A study experiment of auto idle application in the excavator engine performance

NASA Astrophysics Data System (ADS)

Purwanto, Wawan; Maksum, Hasan; Putra, Dwi Sudarno; Azmi, Meri; Wahyudi, Retno

2016-03-01

The purpose of this study was to analyze the effect of applying auto idle to excavator engine performance, such as machine unitization and fuel consumption in Excavator. Steps to be done are to modify the system JA 44 and 67 in Vehicle Electronic Control Unit (V-ECU). The modifications will be obtained from the pattern of the engine speed. If the excavator attachment is not operated, the engine speed will return to the idle speed automatically. From the experiment results the auto idle reduces fuel consumption in excavator engine.

A study experiment of auto idle application in the excavator engine performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Purwanto, Wawan, E-mail: wawan5527@gmail.com; Maksum, Hasan; Putra, Dwi Sudarno, E-mail: dwisudarnoputra@ft.unp.ac.id

2016-03-29

The purpose of this study was to analyze the effect of applying auto idle to excavator engine performance, such as machine unitization and fuel consumption in Excavator. Steps to be done are to modify the system JA 44 and 67 in Vehicle Electronic Control Unit (V-ECU). The modifications will be obtained from the pattern of the engine speed. If the excavator attachment is not operated, the engine speed will return to the idle speed automatically. From the experiment results the auto idle reduces fuel consumption in excavator engine.

Does the availability of artificial cavities affect cavity excavation rates in red-cockaded woodpeckers?

Treesearch

Richard N. Conner; Daniel Saenz; D. Craig Rudolph; Richard R. Schaefer

2002-01-01

Rates of cavity excavation by Red-cockaded Woodpeckers (Picoides borealis) were examined from 1983 to 1999 on the Angelina National Forest in east Texas. We compared the rare of natural cavity excavation between 1983 and 1990 (before artificial cavities were available) with the rate of cavity excavation between 1992 and 1993, a period when...

Continuous Rating for Diggability Assessment in Surface Mines

NASA Astrophysics Data System (ADS)

IPHAR, Melih

2016-10-01

The rocks can be loosened either by drilling-blasting or direct excavation using powerful machines in opencast mining operations. The economics of rock excavation is considered for each method to be applied. If blasting operation is not preferred and also the geological structures and rock mass properties in site are convenient (favourable ground conditions) for ripping or direct excavation method by mining machines, the next step is to determine which machine or excavator should be selected for the excavation purposes. Many researchers have proposed several diggability or excavatability assessment methods for deciding on excavator type to be used in the field. Most of these systems are generally based on assigning a rating for the parameters having importance in rock excavation process. However, the sharp transitions between the two adjacent classes for a given parameter can lead to some uncertainties. In this paper, it has been proposed that varying rating should be assigned for a given parameter called as “continuous rating” instead of giving constant rating for a given class.

The Use of Ground Penetrating Radar to extend the Results of Archaeological Excavation

NASA Astrophysics Data System (ADS)

Utsi, E.

2009-04-01

The condition of the Romano-British archaeological site in Wortley, Gloucestershire, UK is typical of sites of the period in that it has been heavily robbed out since it first fell into disuse. Building materials taken from the site have been re-used over the centuries to construct other local buildings. This makes both preservation of the extant remains and interpretation of the excavation problematic. Following the accidental discovery of the site in the 1980s, a programme of excavation was set in place. This excavation was run as a practical archaeological training school and, as a result, a wide range of archaeological and geophysical techniques were applied to the site. This included the introduction of Ground Penetrating Radar (GPR). The preliminary results of the first GPR used on site were not entirely satisfactory which led to the development of a new radar in the early 1990s, specifically developed for use on archaeological sites. The excavation and GPR results were published in a series of excavation reports [1] [2]. It was not possible to excavate fully for two reasons. Firstly the site crossed present day ownership boundaries and secondly the ownership of the excavation area changed. At this point the excavation was summarily terminated. In 2007, permission was given by the owner of an adjacent property to carry out a GPR survey over their land in order to derive additional information, if possible. An area survey was carried out in May 2007 with reduced transect spacing [3]. The radar data showed similar patterning to that of the original investigation i.e. substantial remains which had been subject to a high degree of post-occupational attrition. Time slices from the radar survey were matched to the principal excavation plans. It proved possible to deduce the full extent of certain partially excavated features, notably the courtyard and bath house. It was also possible to demonstrate that one part of the adjacent property did not contain similar archaeological material. The GPR survey has added significantly to the excavation results and hence to the potential interpretation of the site. Since it will not be possible either to continue the former excavation or to investigate the adjacent land, the information provided by the radar provides a unique insight. [1] Utsi, V (1988) "Ground Radar" in ‘Excavation of a Romano-British Villa at Wortley, Gloucs.' University of Keele Department of Adult & Continuing Education, Keele, 4th interim report. [2] Utsi, V & Utsi, E (1989) "Ground radar survey" in ‘Excavation of a Romano-British Villa at Wortley, Gloucs.' University of Keele, Department of Adult & Continuing Education, Keele, 5th interim report. [3] Utsi Electronics Ltd (2007) "Ground Penetrating Radar Survey of Part of Wortley Romano-British Villa" report to David Wilson, Director, Archaeological Excavation Training School, Cambridge UK.

Impacts of water development on aquatic macroinvertebrates, amphibians, and plants in wetlands of a semi-arid landscape

USGS Publications Warehouse

Euliss, Ned H.; Mushet, David M.

2004-01-01

We compared the macroinvertebrate and amphibian communities of 12 excavated and 12 natural wetlands in western North Dakota, USA, to assess the effects of artificially lengthened hydroperiods on the biotic communities of wetlands in this semi-arid region. Excavated wetlands were much deeper and captured greater volumes of water than natural wetlands. Most excavated wetlands maintained water throughout the study period (May to October 1999), whereas most of the natural wetlands were dry by June. Excavated wetlands were largely unvegetated or contained submergent and deep-marsh plant species. The natural wetlands had two well-defined vegetative zones populated by plant species typical of wet meadows and shallow marshes. Excavated wetlands had a richer aquatic macroinvertebrate community that included several predatory taxa not found in natural wetlands. Taxa adapted to the short hydroperiods of seasonal wetlands were largely absent from excavated wetlands. The amphibian community of natural and excavated wetlands included the boreal chorus frog (Pseudacris maculata), northern leopard frog (Rana pipiens), plains spadefoot (Scaphiopus bombifrons), Woodhouse's toad (Bufo woodhousii woodhousii), and tiger salamander (Ambystoma tigrinum). The plains spadefoot occurred only in natural wetlands while tiger salamanders occurred in all 12 excavated wetlands and only one natural wetland. Boreal chorus frogs and northern leopard frogs were present in both wetland types; however, they successfully reproduced only in wetlands lacking tiger salamanders. Artificially extending the hydroperiod of wetlands by excavation has greatly influenced the composition of native biotic communities adapted to the naturally short hydroperiods of wetlands in this semi-arid region. The compositional change of the biotic communities can be related to hydrological changes and biotic interactions, especially predation related to excavation.

Principles of control for robotic excavation

NASA Astrophysics Data System (ADS)

Bernold, Leonhard E.

The issues of automatic planning and control systems for robotic excavation are addressed. Attention is given to an approach to understanding the principles of path and motion control which is based on scaled modeling and experimentation with different soil types and soil conditions. Control concepts for the independent control of a bucket are discussed, and ways in which force sensors could provide the necessary data are demonstrated. Results of experiments with lunar simulant showed that explosive loosening has a substantial impact on the energy needed during excavation. It is argued that through further laboratory and field research, 'pattern languages' for different excavators and soil conditions could be established and employed for robotic excavation.

Monitoring the excavation damaged zone by three-dimensional reconstruction of electrical resistivity

NASA Astrophysics Data System (ADS)

Lesparre, Nolwenn; Gibert, Dominique; Nicollin, Florence; Nussbaum, Christophe; Adler, Andy

2013-11-01

A damaged zone is formed during the excavation of underground galleries, altering the rock properties. From a perspective of nuclear waste storage in deep geological sites, there is a clear interest to monitor the rock properties in such zones. We constructed electrical resistivity tomograms as a function of time to monitor the damaged area in gallery 04 of the Mont Terri underground rock laboratory (Switzerland). Measurements were performed using electrode rings surrounding the gallery. The experience showed a heterogeneous distribution of damages around the gallery and their fast formation after the excavation. Two main areas were concerned by damage formation, located in regions where the bedding was tangential to the excavated gallery. Such regions represented an extension of about 2 m along the gallery walls and reached a depth of 1.5 m. Main damages were created during the next months following the excavation process. Slight variations were still observed 3 yr after the excavation that may be related to the gallery environmental condition fluctuation. The method applied here demonstrates the interest to monitor the whole region surrounding excavated galleries dedicated to host nuclear wastes.

Conceptual design of equipment to excavate and transport regolith from the lunar maria

NASA Technical Reports Server (NTRS)

Detwiler, Mark; Foong, Chee Seng; Stocklin, Catherine

1990-01-01

NASA hopes to have a manned lunar outpost completed by 2005. In order to establish the base, regolith must be excavated from the lunar surface. Regolith will be used as a source for life-supporting elements and as radiation shielding for the lunar outpost. The design team from the University of Texas at Austin designed excavation and transportation equipment for initial operations of the lunar base. The design team also characterized the elements to be found in the regolith and determined the power required to excavate regolith. The characterization of the soil was based on a literature review of lunar geography. Power requirements for excavation were developed by adapting terrestrial equations for excavation power requirements and adapting them to lunar soil conditions. The design of the excavation and transportation equipment was broken into three functions: loosing, collecting, and transporting. A scarifier was selected to loosen, a bucket was selected to collect, and a load-haul system was selected to transport. The functions are powered by a modular fuel cell powered vehicle that provides power for motion of the equipment.

Intelligent excavator control system for lunar mining system

NASA Astrophysics Data System (ADS)

Lever, Paul J. A.; Wang, Fei-Yue

1995-01-01

A major benefit of utilizing local planetary resources is that it reduces the need and cost of lifting materials from the Earth's surface into Earth orbit. The location of the moon makes it an ideal site for harvesting the materials needed to assist space activities. Here, lunar excavation will take place in the dynamic unstructured lunar environment, in which conditions are highly variable and unpredictable. Autonomous mining (excavation) machines are necessary to remove human operators from this hazardous environment. This machine must use a control system structure that can identify, plan, sense, and control real-time dynamic machine movements in the lunar environment. The solution is a vision-based hierarchical control structure. However, excavation tasks require force/torque sensor feedback to control the excavation tool after it has penetrated the surface. A fuzzy logic controller (FLC) is used to interpret the forces and torques gathered from a bucket mounted force/torque sensor during excavation. Experimental results from several excavation tests using the FLC are presented here. These results represent the first step toward an integrated sensing and control system for a lunar mining system.

GPS-Based Excavation Encroachment Notification

DOT National Transportation Integrated Search

2011-10-31

Excavation damage is the primary threat to the integrity of the natural gas distribution system. According to the Common Ground Alliance, the two primary root causes of excavation damage are failure to notify the one-call center and careless excavati...

29 CFR 1926.913 - Blasting in excavation work under compressed air.

Code of Federal Regulations, 2014 CFR

2014-07-01

... rock face is approaching mixed face, and when tunnel excavation is in mixed face, blasting shall be... tunnel excavation in rock face approaches mixed face, to determine the general nature and extent of rock...

29 CFR 1926.913 - Blasting in excavation work under compressed air.

Code of Federal Regulations, 2012 CFR

2012-07-01

... rock face is approaching mixed face, and when tunnel excavation is in mixed face, blasting shall be... tunnel excavation in rock face approaches mixed face, to determine the general nature and extent of rock...

Reducing Extra-Terrestrial Excavation Forces with Percussion

NASA Technical Reports Server (NTRS)

Mueller, Robert; Schuler, Jason M.; Smith, Jonathan Drew; Nick, Andrew J.; Lippitt, Thomas

2012-01-01

High launch costs and mission requirements drive the need for low mass excavators with mobility platforms, which in turn have little traction and excavation reaction capacity in low gravity environments. This presents the need for precursor and long term future missions with low mass robotic mining technology to perform In-Situ Resource Utilization (ISRU) tasks. This paper discusses a series of experiments that investigate the effectiveness of a percussive digging device to reduce excavation loads and thereby the mass of the excavator itself. A percussive mechanism and 30" wide pivoting bucket were attached at the end of the arm simulating a basic backhoe with a percussion direction tangent to the direction of movement. Impact energies from 13.6J to 30.5J and frequencies from 0 BPM to 700 BPM were investigated. A reduction in excavation force of as much as 50% was achieved in this experimental investigation.

Study on Excavation of Particular Part of Underground Cavern for Hydropower Station

NASA Astrophysics Data System (ADS)

Yang, Yang; Zhang, Feng; Shang, Qin; Zheng, Huakang

2018-01-01

In the present study, regarding four particular parts of underground cavern for hydropower station, i.e., crown, high sidewall, the intersection between high sidewall and tunnel and tailrace tunnel, by summarizing the previous construction experience, we have proposed the excavation approach based on “middle first and edge later, soft first and hard later”, “layered construction by excavating the thin layer first and supporting as the layer advances”, “tunnel first and wall later, small tunnels into large ones” and “excavating tunnels supported by separation piers”. In addition, the proposed excavation approach has been analyzed and verified with finite element numerical simulation. The result has indicated that the proposed special approach is reasonable and effective to reduce the turbulence on surrounding rocks, lower the influence of unloading during excavating and enhance the local and global stability of caverns and surrounding rocks.

Acoustic emission and ultrasonic-velocity methods used to characterise the excavation disturbance associated with deep tunnels in hard rock

NASA Astrophysics Data System (ADS)

Falls, Stephen D.; Young, R. Paul

1998-04-01

Acoustic emission (AE) and ultrasonic-velocity monitoring studies have been undertaken at both the Atomic Energy of Canada Limited (AECL) Underground Research Laboratory (URL) and at the Swedish Nuclear Fuel Waste Management Company (SKB) Hard Rock Laboratory (HRL). At both locations the excavations were tunnels in granitic material at approximately 420 m depth. However, the stress regime was more severe at the URL Mine-by tunnel site than the HRL ZEDEX tunnel. Different parts of the ZEDEX tunnel were created using different excavation techniques. Using AE and ultrasonic techniques to study these tunnels we have been able to examine the nature of the excavation-disturbed zone around the tunnel, as well as examining the effects of different stress regimes and excavation techniques. Studies were undertaken both during and after the Mine-by tunnel excavation and during excavation in the ZEDEX tunnel. AE monitoring in the wall of the Mine-by tunnel during excavation showed that some activity occurred in the sidewall regions, but the spatial density of AE hypocentres increased toward the regions in the floor and roof of the tunnel where breakout notches formed. This sidewall activity was clustered primarily within 0.5 m of the tunnel wall. AE monitoring in the floor of the tunnel showed that small numbers of AE continued to occur in the notch region in the floor of the tunnel over 2 years after excavation was completed. This activity became more acute as the rock was heated, imposing thermally induced stresses on the volume. Ultrasonic-velocity studies both in the floor and the wall of the tunnel showed that the velocity is strongly anisotropic with the direction of slowest velocity orthogonal to the tunnel surface. The velocity increased with distance into the rock from the tunnel surface. In the floor, this effect was seen up to 2 m from the tunnel surface. Most of the change occurred within the first 0.5 m from the tunnel perimeter. At the lower-stress HRL, most of the AE again occur very close to the tunnel surface. The occurrence of AE under relatively low stress conditions suggests that the regions experiencing AE activity were damaged during the excavation process, thereby reducing their strength. The section of tunnel excavated by a tunnel-boring machine had fewer events, clustered much closer to the tunnel surface, than the sections excavated using drill and blast excavation techniques. P-wave velocity changes of only about 0.1% were experienced due to the tunnel excavation for ray paths within zero to 2 m from the tunnel surface indicating that crack damage was relatively low.

Reducing Extra-Terrestrial Excavation Forces with Percussion

NASA Technical Reports Server (NTRS)

Schuler, Jason; Mueller, Robert; Smith, Drew; Nick, Andrew; Lippitt, Thomas

2012-01-01

High launch costs and mission requirements drive the need for low mass excavators with mobility platforms, which in turn have little traction and excavation reaction capacity in low gravity environments. This presents the need for precursor and long term future missions with low mass robotic mining technology to perform In-Situ Resource Utilization (ISRU) tasks. This paper discusses a series of experiments that investigate the effectiveness of a percussive digging device to reduce excavation loads and thereby the mass of the excavator itself. The goal of percussive excavation is to fluidize dry regolith in front of the leading edge of the tool by mechanically separating the microscopic interlocking grains resulting in a reduced force needed to shear the soil. There are several variables involved with this technique; this experiment varied: Impact energy, frequency, and excavation speed and held constant: impact direction, depth of cut, angle of tool, and soil bulk density. The test apparatus consisted of an aluminum truss bridge with a central pivoting arm. Attached to the arm was a winch with a load cell in line that recorded the tension in the cable and therefore the excavation load. The arm could be adjusted for excavation depth which was recorded along with the arm angle relative to the bridge. A percussive mechanism and 30" wide pivoting bucket were attached at the end of the arm simulating a basic backhoe with a percussion direction tangent to the direction of . movement. Internally the mechanism used a set of die springs and barrel cam to produce the percussive blow. By changing the springs and the speed of the motor the impact energy and frequency of percussion could be varied independently. Impact energies from 11.2J to 30.5J and frequencies from 0 BPM to 700 BPM were investigated. A reduction in excavation force of as much as 51% was achieved in this experimental investigation. Smaller percussive digging implements, tested by others, have achieved a reduction of as much as 72%. This paper will examine the effects of impact energy, frequency, scaling and their effect on excavation forces in a dry granular material such as lunar regolith. The past several years have shown an increasing interest in mining space resources both for exploration and commercial enterprises. This work studied the benefits and risks of percussive excavation and preliminry results indicate that this technique may become an enabling technology for extra-terrestrial excavation of regolith and ice.

A Comparative Evaluation of the Efficacy of Different Caries Excavation Techniques in reducing the Cariogenic Flora: An in vivo Study.

PubMed

Hassan, Afrah Fatima; Yadav, Gunjan; Tripathi, Abhay Mani; Mehrotra, Mridul; Saha, Sonali; Garg, Nishita

2016-01-01

Caries excavation is a noninvasive technique of caries removal with maximum preservation of healthy tooth structure. To compare the efficacy of three different caries excavation techniques in reducing the count of cariogenic flora. Sixty healthy primary molars were selected from 26 healthy children with occlusal carious lesions without pulpal involvement and divided into three groups in which caries excavation was done with the help of (1) carbide bur; (2) polymer bur using slow-speed handpiece; and (3) ultrasonic tip with ultrasonic machine. Samples were collected before and after caries excavation for microbiological analysis with the help of sterile sharp spoon excavator. Samples were inoculated on blood agar plate and incubated at 37°C for 48 hours. After bacterial cultivation, the bacterial count of Streptococcus mutans was obtained. All statistical analysis was performed using SPSS 13 statistical software version. Kruskal-Wallis analysis of variance, Wilcoxon matched pairs test, and Z test were performed to reveal the statistical significance. The decrease in bacterial count of S. mutans before and after caries excavation was significant (p < 0.001) in all the three groups. Carbide bur showed most efficient reduction in cariogenic flora, while ultrasonic tip showed almost comparable results, while polymer bur showed least reduction in cariogenic flora after caries excavation. Hassan AF, Yadav G, Tripathi AM, Mehrotra M, Saha S, Garg N. A Comparative Evaluation of the Efficacy of Different Caries Excavation Techniques in reducing the Cariogenic Flora: An in vivo Study. Int J Clin Pediatr Dent 2016;9(3):214-217.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, H.R.; Overbey, W.K. Jr.; Koperna, G.J. Jr.

The purpose of this study is to assess the state-of-the-art of excavation technology as related to environmental remediation applications. A further purpose is to determine which of the excavation technologies reviewed could be used by the US Corp of Engineers in remediating contaminated soil to be excavated in the near future for construction of a new Lock and Dam at Winfield, WV. The study is designed to identify excavation methodologies and equipment which can be used at any environmental remediation site but more specifically at the Winfield site on the Kanawha River in Putnam County, West Virginia. A technical approachmore » was determined whereby a functional analysis was prepared to determine the functions to be conducted during the excavation phase of the remediation operations. A number of excavation technologies were identified from the literature. A set of screening criteria was developed that would examine the utility and ranking of the technologies with respect to the operations that needed to be conducted at the Winfield site. These criteria were performance, reliability, implementability, environmental safety, public health, and legal and regulatory compliance. The Loose Bulk excavation technology was ranked as the best technology applicable to the Winfield site. The literature was also examined to determine the success of various methods of controlling fugitive dust. Depending upon any changes in the results of chemical analyses, or prior remediation of the VOCs from the vadose zone, consideration should be given to testing a new ``Pneumatic Excavator`` which removes the VOCs liberated during the excavation process as they outgas from the soil. This equipment however would not be needed on locations with low levels of VOC emissions.« less

10 CFR 60.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

.... Site characterization includes borings, surface excavations, excavation of exploratory shafts, limited subsurface lateral excavations and borings, and in situ testing at depth needed to determine the suitability of the site for a geologic repository, but does not include preliminary borings and geophysical...

10 CFR 60.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

.... Site characterization includes borings, surface excavations, excavation of exploratory shafts, limited subsurface lateral excavations and borings, and in situ testing at depth needed to determine the suitability of the site for a geologic repository, but does not include preliminary borings and geophysical...

10 CFR 60.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

.... Site characterization includes borings, surface excavations, excavation of exploratory shafts, limited subsurface lateral excavations and borings, and in situ testing at depth needed to determine the suitability of the site for a geologic repository, but does not include preliminary borings and geophysical...

2012 Alabama Lunabotics Systems Engineering Paper

NASA Technical Reports Server (NTRS)

Baker, Justin; Ricks, Kenneth; Hull, Bethanne J.

2012-01-01

Excavation will hold a key role for future lunar missions. NASA has stated that "advances in lunar regolith mining have the potential to significantly contribute to our nation's space vision and NASA space exploration operations." [1]. The Lunabotics Mining Competition is an event hosted by NASA that is meant to encourage "the development of innovative lunar excavation concepts from universities which may result in clever ideas and solutions which could be applied to an actual lunar excavation device or payload." [2]. Teams entering the competition must "design and build a remote controlled or autonomous excavator, called a lunabot, that can collect and deposit a minimum of 10 kilograms of lunar simulant within 10 minutes." [2]. While excavation will play an important part in lunar missions, there will still be many other tasks that would benefit from robotic assistance. An excavator might not be as well suited for these tasks as other types of robots might be. For example a lightweight rover would do well with reconnaissance, and a mobile gripper arm would be fit for manipulation, while an excavator would be comparatively clumsy and slow in both cases. Even within the realm of excavation it would be beneficial to have different types of excavators for different tasks, as there are on Earth. The Alabama Lunabotics Team at the University of Alabama has made it their goal to not only design and build a robot that could compete in the Lunabotics Mining Competition, but would also be a multipurpose tool for future NASA missions. The 2010-2011 resulting robot was named the Modular Omnidirectional Lunar Excavator (MOLE). Using the Systems Engineering process and building off of two years of Lunabotics experience, the 20ll-2012 Alabama Lunabotics team (Team NASACAR) has improved the MOLE 1.0 design and optimized it for the 2012 Lunabotics Competition rules [I]. A CAD model of MOLE 2.0 can be seen below in Fig. 1.

Middle Stone Age stratigraphy and excavations at Die Kelders Cave 1 (Western Cape Province, South Africa): the 1992, 1993, and 1995 field seasons.

PubMed

Marean, C W; Goldberg, P; Avery, G; Grine, F E; Klein, R G

2000-01-01

Die Kelders Cave 1, first excavated under the direction of Franz Schweitzer in 1969-1973, was re-excavated between 1992 and 1995 by a combined team from the South African Museum, SUNY at Stony Brook, and Stanford University. These renewed excavations enlarged the artefactual and faunal samples from the inadequately sampled and less intensively excavated lower Middle Stone Age (MSA) layers, increased our understanding of the complex site formation processes within the cave, enlarged the hominid sample from the MSA deposits, and generated ESR, TL, and OSL dates for the MSA layers. Importantly, these new excavations dramatically improved our comprehension of the vertical and lateral characteristics of the MSA stratigraphy. Surface plotting of the MSA layers has led to the identification of at least two major zones of subsidence that significantly warped the layers, draping some along the eroding surface contours of major blocks of fallen limestone roof rock. A third zone of subsidence is probably present in the older excavations. Dramatic roof falls of very large limestone blocks occurred at least twice-once in the middle of Layer 4/5 where the roof blocks were only slightly weathered after collapse, and at the top of Layer 6 where the blocks weathered heavily after collapse, producing a zone of decomposed rock around the blocks. Many of the sandy strata are cut by small and localized faults and slippages. All of the strata documented by Schweitzer's excavations are present throughout the exposed area to the west of his excavated area, where many of them thicken and become more complex. Layer 6, the thickest MSA layer, becomes less diagenetically altered and compressed to the west. Copyright 2000 Academic Press.

Cratos: A Simple Low Power Excavation and Hauling System for Lunar Oxygen Production and General Excavation Tasks

NASA Technical Reports Server (NTRS)

Caruso, John J.; Greer, Lawrence C.; John, Wentworth T.; Spina, Dan C.; Krasowski, Mike J.; Abel, Phillip B.; Prokop, Norman F.; Flatico, Joseph M.; Sacksteder, Kurt R.

2007-01-01

The development of a robust excavating and hauling system for lunar and planetary excavation is critical to the NASA mission to the Moon and Mars. Cratos was developed as a low center of gravity, small (.75m x .75m x 0.3m), low power tracked test vehicle. The vehicle was modified to excavate and haul because it demonstrated good performance capabilities in a laboratory and field testing. Tested on loose sand in the SLOPE facility, the vehicle was able to pick up, carry, and dump sand, allowing it to accomplish the standard requirements delivery of material to a lunar oxygen production site. Cratos can pick up and deliver raw material to a production plant, as well as deliver spent tailings to a disposal site. The vehicle can complete many other In-Situ Resource Utilization (ISRU) excavation chores and in conjunction with another vehicle or with additional attachments may be able to accomplish all needed ISRU tasks.

Sequential soil transport and its influence on the spatial organisation of collective digging in leaf-cutting ants.

PubMed

Pielström, Steffen; Roces, Flavio

2013-01-01

The Chaco leaf-cutting ant Atta vollenweideri (Forel) inhabits large and deep subterranean nests composed of a large number of fungus and refuse chambers. The ants dispose of the excavated soil by forming small pellets that are carried to the surface. For ants in general, the organisation of underground soil transport during nest building remains completely unknown. In the laboratory, we investigated how soil pellets are formed and transported, and whether their occurrence influences the spatial organisation of collective digging. Similar to leaf transport, we discovered size matching between soil pellet mass and carrier mass. Workers observed while digging excavated pellets at a rate of 26 per hour. Each excavator deposited its pellets in an individual cluster, independently of the preferred deposition sites of other excavators. Soil pellets were transported sequentially over 2 m, and the transport involved up to 12 workers belonging to three functionally distinct groups: excavators, several short-distance carriers that dropped the collected pellets after a few centimetres, and long-distance, last carriers that reached the final deposition site. When initiating a new excavation, the proportion of long-distance carriers increased from 18% to 45% within the first five hours, and remained unchanged over more than 20 hours. Accumulated, freshly-excavated pellets significantly influenced the workers' decision where to start digging in a choice experiment. Thus, pellets temporarily accumulated as a result of their sequential transport provide cues that spatially organise collective nest excavation.

Crane and Excavator Operator.

ERIC Educational Resources Information Center

Marine Corps Inst., Washington, DC.

Developed as part of the Marine Corps Institute (MCI) correspondence training program, this course on crane and excavator operation is designed to enable the crane and excavator operator to perform his/her duties more proficiently. Introductory materials include specific information for MCI students, a course introduction, and a study guide…

Telerobotic Excavator Designed to Compete in NASA's Lunabotics Mining Competition

NASA Technical Reports Server (NTRS)

Nash, Rodney; Santin, Cara; Yousef, Ahmed; Nguyen, Thien; Helferty, John; Pillapakkam, Shriram

2011-01-01

The second annual NASA Lunabotics Mining competition is to be held in May 23-28, 2011. The goal of the competition is for teams of university level students to design, build, test and compete with a fully integrated lunar excavator on a simulated lunar surface. Our team, named Lunar Solutions I, will be representing Temple University's College of Engineering in the competition. The team's main goal was to build a robot which is able to compete with other teams, and ultimately win the competition. The main challenge of the competition was to build a wireless robot that can excavate and collect a minimum of 10 kilograms of the regolith material within 15 minutes. The robot must also be designed to operate in conditions similar to those found on the lunar surface. The design of the lunar excavator is constrained by a set of requirements determined by NASA and detailed in the competition's rulebook. The excavator must have the ability to communicate with the "main base" wirelessly, and over a Wi-Fi network. Human operators are located at a remote site approximately 60 meters away from the simulated lunar surface upon which the robot must excavate the lunar regolith surface. During the competition, the robot will operate in a separate area from the control room in an area referred to as the "Lunarena." From the control room, the operators will have to control the robot using visual feedback from cameras placed both within the arena and on the robot. Using this visual feedback the human operators control the robots movement using both keyboard and joystick commands. In order to place in the competition, a minimum of 10 kg of regolith material has to be excavated, collected, and dumped into a specific location. For that reason, the robot must be provided with an effective and powerful excavation system. Our excavator uses tracks for the drive system. After performing extensive research and trade studies, we concluded that tracks would be the most effective method for transporting the excavator. When designing the excavation system, we analyzed several design options from the previous year's competition. We decided to use a front loader to collect the material, rather than a conveyer belt system or auger. Many of the designs from last year's competition used a conveyer belt mechanism to mine regolith and dump it into a temporary storage bin place on the robot. Using the front end loader approach allowed us to combine the scooping system and storage unit, which meant that the excavation system required less space.

Excavated Soils Management Plan for AOCs 44 and 52, Fort Devens

DTIC Science & Technology

1994-05-01

I FORT DEVENS AOCs 44 AND 52 I I I FINAL EXCAVATED SOILS MANAGEMENT PLAN DATA ITEM A009I I U 20070424310 I CONTRACT DAAA15-91-D-0008 I U.S. ARMY...obselete FINAL EXCAVATED SOILS MANAGEMENT PLAN FOR AOCs 44 AND 52 FORT DEVENS Prepared for. U.S. Army Enviromnental Center Aberdeen Proving Ground, Maryland...BLANK 3 I I I I I I I I I I FINAL EXCAVATED SOILS MANAGEMENT PLAN FOR AOCs 44 AND 52 FORT DEVENS TABLE OF CONTENTS 1 Section Title Page No. 1.0

SLOPE STABILITY EVALUATION AND EQUIPMENT SETBACK DISTANCES FOR BURIAL GROUND EXCAVATIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

MCSHANE DS

2010-03-25

After 1970 Transuranic (TRU) and suspect TRU waste was buried in the ground with the intention that at some later date the waste would be retrieved and processed into a configuration for long term storage. To retrieve this waste the soil must be removed (excavated). Sloping the bank of the excavation is the method used to keep the excavation from collapsing and to provide protection for workers retrieving the waste. The purpose of this paper is to document the minimum distance (setback) that equipment must stay from the edge of the excavation to maintain a stable slope. This evaluation examinesmore » the equipment setback distance by dividing the equipment into two categories, (1) equipment used for excavation and (2) equipment used for retrieval. The section on excavation equipment will also discuss techniques used for excavation including the process of benching. Calculations 122633-C-004, 'Slope Stability Analysis' (Attachment A), and 300013-C-001, 'Crane Stability Analysis' (Attachment B), have been prepared to support this evaluation. As shown in the calculations the soil has the following properties: Unit weight 110 pounds per cubic foot; and Friction Angle (natural angle of repose) 38{sup o} or 1.28 horizontal to 1 vertical. Setback distances are measured from the top edge of the slope to the wheels/tracks of the vehicles and heavy equipment being utilized. The computer program utilized in the calculation uses the center of the wheel or track load for the analysis and this difference is accounted for in this evaluation.« less

2010 NASA Exploration Systems Mission Directorate: Lunabotics Mining Competition Systems Engineering Paper

NASA Technical Reports Server (NTRS)

2010-01-01

A fast growing approach in determining the best design concept for a problem is to hold a competition in which the rules are based on requirements similar to the actual problem. By going public with such competitions, sponsoring entities receive some of the most innovative engineering solutions in a fraction of the time and cost it would have taken to develop such concepts internally. Space exploration is a large benefactor of such design competitions as seen by the results of X-Prize Foundation and NASA lunar excavation competitions [1]. The results of NASA's past lunar excavator challenges has led to the need for an effective means of collecting lunar regolith in the absence of human beings. The 2010 Exploration Systems Mission Directorate (ESMD) Lunar Excavation Challenge was created "to engage and retain students in science, technology, engineering, and mathematics, or STEM, in a competitive environment that may result in innovative ideas and solutions, which could be applied to actual lunar excavation for NASA." [2]. The ESMD Challenge calls for "teams to use telerobotics or autonomous operations to excavate at least 10kg of lunar regolith simulant in a 15 minute time limit" [2]. The Systems Engineering approach was used in accordance with Auburn University's mechanical engineering senior design course (MECH 4240-50) to develop a telerobotic lunar excavator, seen in Fig. 1, that fulfilled requirements imposed by the NASA ESMD Competition Rules. The goal of the senior design project was to have a validated lunar excavator that would be used in the NASA ESMD lunar excavation challenge.

A Top Pilot Tunnel Preconditioning Method for the Prevention of Extremely Intense Rockbursts in Deep Tunnels Excavated by TBMs

NASA Astrophysics Data System (ADS)

Zhang, Chuanqing; Feng, Xiating; Zhou, Hui; Qiu, Shili; Wu, Wenping

2012-05-01

The headrace tunnels at the Jinping II Hydropower Station cross the Jinping Mountain with a maximum overburden depth of 2,525 m, where 80% of the strata along the tunnels consist of marble. A number of extremely intense rockbursts occurred during the excavation of the auxiliary tunnels and the drainage tunnel. In particular, a tunnel boring machine (TBM) was destroyed by an extremely intense rockburst in a 7.2-m-diameter drainage tunnel. Two of the four subsequent 12.4-m-diameter headrace tunnels will be excavated with larger size TBMs, where a high risk of extremely intense rockbursts exists. Herein, a top pilot tunnel preconditioning method is proposed to minimize this risk, in which a drilling and blasting method is first recommended for the top pilot tunnel excavation and support, and then the TBM excavation of the main tunnel is conducted. In order to evaluate the mechanical effectiveness of this method, numerical simulation analyses using the failure approaching index, energy release rate, and excess shear stress indices are carried out. Its construction feasibility is discussed as well. Moreover, a microseismic monitoring technique is used in the experimental tunnel section for the real-time monitoring of the microseismic activities of the rock mass in TBM excavation and for assessing the effect of the top pilot tunnel excavation in reducing the risk of rockbursts. This method is applied to two tunnel sections prone to extremely intense rockbursts and leads to a reduction in the risk of rockbursts in TBM excavation.

Visualization of lunar excavation test in NASA Glenn's GRUVE Lab

NASA Image and Video Library

1969-12-31

Calvin Robinson of NASA Glenn's GVIS Team demonstrates a visualization of an excavation test conducted at NASA Glenn Research Center's SLOPE Lab ( https://rt.grc.nasa.gov/main/rlc/simu... ) . The visualization shows the flow of a lunar soil simulant as it flows in and past a proposed excavation bucket.

29 CFR 1926.913 - Blasting in excavation work under compressed air.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 8 2010-07-01 2010-07-01 false Blasting in excavation work under compressed air. 1926.913... Use of Explosives § 1926.913 Blasting in excavation work under compressed air. (a) Detonators and... connecting wires are connected up. (b) When detonators or explosives are brought into an air lock, no...

Regolith Advanced Surface Systems Operations Robot Excavator

NASA Technical Reports Server (NTRS)

Mueller, Robert P.; Smith, Jonathan D.; Ebert, Thomas; Cox, Rachel; Rahmatian, Laila; Wood, James; Schuler, Jason; Nick, Andrew

2013-01-01

The Regolith Advanced Surface Systems Operations Robot (RASSOR) excavator robot is a teleoperated mobility platform with a space regolith excavation capability. This more compact, lightweight design (<50 kg) has counterrotating bucket drums, which results in a net-zero reaction horizontal force due to the self-cancellation of the symmetrical, equal but opposing, digging forces.

Gravity anomaly at a Pleistocene lake bed in NW Alaska interpreted by analogy with Greenland's Lake Taserssauq and its floating ice tongue

USGS Publications Warehouse

Barnes, D.F.

1987-01-01

A possible example of a very deep glacial excavation is provided by a distinctive gravity low located at the front of a valley glacier that once flowed into glacial Lake Aniuk (formerly Lake Noatak) in the western Brooks Range. Geologic and geophysical data suggest that sediments or ice filling a glacially excavated valley are the most probable cause of the 30-50 mGal anomaly. Reasonable choices of geometric models and density contrasts indicate that the former excavation is now filled with a buried-ice thickness of 700 m or sediment thicknesses greater than 1 km. No direct evidence of efficient excavation was observed in Greenland, but efficient glacial erosion behind a floating polar ice tongue could explain the excavation that caused the Alaskan gravity anomaly. -from Author

Impact-Actuated Digging Tool for Lunar Excavation

NASA Technical Reports Server (NTRS)

Wilson, Jak; Chu, Philip; Craft, Jack; Zacny, Kris; Santoro, Chris

2013-01-01

NASA s plans for a lunar outpost require extensive excavation. The Lunar Surface Systems Project Office projects that thousands of tons of lunar soil will need to be moved. Conventional excavators dig through soil by brute force, and depend upon their substantial weight to react to the forces generated. This approach will not be feasible on the Moon for two reasons: (1) gravity is 1/6th that on Earth, which means that a kg on the Moon will supply 1/6 the down force that it does on Earth, and (2) transportation costs (at the time of this reporting) of $50K to $100K per kg make massive excavators economically unattractive. A percussive excavation system was developed for use in vacuum or nearvacuum environments. It reduces the down force needed for excavation by an order of magnitude by using percussion to assist in soil penetration and digging. The novelty of this excavator is that it incorporates a percussive mechanism suited to sustained operation in a vacuum environment. A percussive digger breadboard was designed, built, and successfully tested under both ambient and vacuum conditions. The breadboard was run in vacuum to more than 2..times the lifetime of the Apollo Lunar Surface Drill, throughout which the mechanism performed and held up well. The percussive digger was demonstrated to reduce the force necessary for digging in lunar soil simulant by an order of magnitude, providing reductions as high as 45:1. This is an enabling technology for lunar site preparation and ISRU (In Situ Resource Utilization) mining activities. At transportation costs of $50K to $100K per kg, reducing digging forces by an order of magnitude translates into billions of dollars saved by not launching heavier systems to accomplish excavation tasks necessary to the establishment of a lunar outpost. Applications on the lunar surface include excavation for habitats, construction of roads, landing pads, berms, foundations, habitat shielding, and ISRU.

The Haw River Sites: Archaeological Investigations at Two Stratified Sites in the North Carolina Piedmont. Volume III.

DTIC Science & Technology

1982-04-01

Excavation Unit 5 - Square 8 - Level 4 - Feature 12 - n - 12 (ID numbers 368-379 in Appendix 3, Table 3) Vessel II Block C - Excavation Unit 6 - Square 8...Level 4 - Feature 7 - See Figure 7.13 - n 38 (ID numbers 380-417 In Appendix 3, Table 3) OO Vessel Ill Block C - Excavation Unit 7 - Square 1 - levels...4-8 - Feature 5 - See Figure 7.12 - n - 90 (ID numbers 418-507 In Appendix 3, Table 3) Vessel IV Block C - Excavation Unit 7 - Square 1 - Levels 4-8

Woodpecker Excavation and Use of Cavities in Polystyrene Snags

Treesearch

Richard N. Conner; Daniel Saenz

1996-01-01

We examined woodpecker excavation and use of artificial polystyrene snags in four forest types in eastern Texas for five years. Twenty-three of 47 artificial snags were used by Downy Woodpeckers (Picoides pubescens) for cavity excavation and subsequent nocturnal roosting; they did not use the artificial snags for nesting. Although six ather species of woodpeckers...

Woodpecker woes: the right tree can be hard to find

Treesearch

Natasha Vizcarra; Teresa. Lorenz

2017-01-01

Woodpeckers and other cavity-excavating birds worldwide are keystone species. These birds excavate their nests out of solid wood, and because their nests are often well protected against predators and the environment, other species use and compete for their old, vacant nests. The presence of cavity-excavating birds in forests has far-reaching effects on species...

Measurement of PM and its chemical composition in real-world emissions from non-road and on-road diesel vehicles

NASA Astrophysics Data System (ADS)

Cui, Min; Chen, Yingjun; Feng, Yanli; Li, Cheng; Zheng, Junyu; Tian, Chongguo; Yan, Caiqing; Zheng, Mei

2017-06-01

With the rapid growth in the number of both non-road and on-road diesel vehicles, the adverse effects of particulate matter (PM) and its constituents on air quality and human health have attracted increasing attentions. However, studies on the characteristics of PM and its composition emitted from diesel vehicles are still scarce, especially under real-world driving conditions. In this study, six excavators and five trucks that provided a wide range of emission standards and operation modes were tested, and PM emissions and their constituents - including organic carbon (OC), elemental carbon (EC), water-soluble ions (WSIs), elements, and organic species like polycyclic aromatic hydrocarbons (PAHs), n-alkanes, and hopanes - as well as steranes were analyzed and characterized. The average emission factors for PM (EFPM) from excavator and truck emissions were 829 ± 806 and 498 ± 234 mg kg-1 fuel, respectively. EFPM and PM constituents were significantly affected by fuel quality, operational mode, and emission standards. A significant correlation (R2 = 0. 79, p < 0. 01) was found between EFPM for excavators and the sulfur contents in fuel. The highest average EFPM for working excavators was 904 ± 979 mg kg-1 fuel as a higher engine load required in this mode. From pre-stage 1 to stage 2, the average EFPM for excavators decreased by 58 %. For trucks, the average non-highway EFPM at 548 ± 311 mg kg-1 fuel was higher than the highway EFPM at 497 ± 231 mg kg-1 fuel. Moreover, the reduction rates were 63.5 and 65.6 % when switched from China II and III to China IV standards, respectively. Generally, the PM composition emitted from excavators was dominated by OC (39. 2 ± 21. 0 %) and EC (33. 3 ± 25. 9 %); PM from trucks was dominated by EC (26. 9 ± 20. 8 %), OC (9. 89 ± 12 %), and WSIs (4. 67 ± 5. 74 %). The average OC / EC ratios for idling and working excavators were 3 to 4 times higher than those for moving excavators. Although the EFPM for excavators and trucks was reduced with the constraint of regulations, the element fractions for excavators increased from 0.49 % in pre-stage 1 to 3.03 % in stage 2, and the fraction of WSIs for the China IV truck was 5 times higher than the average value of all other-level trucks. Furthermore, as compared with other diesel vehicles, wide ranges were found for excavators of the ratios of benzo[a]anthracene / (benzo[a]anthracene + chrysene) (0.26-0.86), indeno[1,2,3-cd]pyrene / (indeno[1,2,3-cd]pyrene + benzo[ghi]perylene) (0.20-1.0), and fluoranthene / (fluoranthene + pyrene) (0.24-0.87), which might be a result of the complex characteristics of the excavator operation modes. A comparison of our results with those in the literature revealed that on-board measurement data more accurately reflect actual conditions. Although the fractions of the 16 priority PAHs in PM from the excavator and truck emissions were similar, the equivalent concentrations of total benzo[a]pyrene of excavators were 31 times than that for trucks, implying that more attention should be paid to non-road vehicle emissions.

Failure Mechanisms and Evolution Assessment of the Excavation Damaged Zones in a Large-Scale and Deeply Buried Underground Powerhouse

NASA Astrophysics Data System (ADS)

Li, Hai-bo; Liu, Ming-chang; Xing, Wan-bo; Shao, Shuai; Zhou, Jia-wen

2017-07-01

The Jinping I underground powerhouse is deeply buried and is one of the largest underground powerhouses in China. As a result of high levels of in situ stress, complex geological conditions and the effects of excavation in adjacent caverns, the surrounding rock mass has been severely deformed and broken, and excavation damaged zones (EDZs) have become major obstacles to the design of cavern excavation and support. Field investigations and monitoring data indicated that there are two main modes of failure: high tangential stress induced failure and progressive failure, which have occurred on the mountain side and the river valley side of the Jinping I underground powerhouse. These two main modes of failure were due to strong secondary principal stress forces in the sub-parallel directions and sub-vertical directions, acting on the axes of the main powerhouse on the mountain side and on the river valley side, respectively. Deformations and EDZs on the river valley side were generally larger than those found along the mountain side, and the distribution of deformations was consistent with the distribution of EDZs. The evolution of the EDZ on the river valley side has clearly been time dependent, especially along the downstream arch abutment, and the EDZ was considerably enlarged with further excavation. Additionally, the deformation of the surrounding rock mass was first initiated from the edge of the excavation area and gradually extended to deeper areas away from the opening. However, the EDZ on the mountain side was enlarged only during the first two phases of excavation. The extension of pre-existing cracks and the creation of new fractures has mainly occurred in the oldest EDZ section, and the HDZ has been visibly enlarged, whereas the EDZ has shown little change in other excavation phases.

Energy-saving analysis of hydraulic hybrid excavator based on common pressure rail.

PubMed

Shen, Wei; Jiang, Jihai; Su, Xiaoyu; Karimi, Hamid Reza

2013-01-01

Energy-saving research of excavators is becoming one hot topic due to the increasing energy crisis and environmental deterioration recently. Hydraulic hybrid excavator based on common pressure rail (HHEC) provides an alternative with electric hybrid excavator because it has high power density and environment friendly and easy to modify based on the existing manufacture process. This paper is focused on the fuel consumption of HHEC and the actuator dynamic response to assure that the new system can save energy without sacrificing performance. Firstly, we introduce the basic principle of HHEC; then, the sizing process is presented; furthermore, the modeling period which combined mathematical analysis and experiment identification is listed. Finally, simulation results show that HHEC has a fast dynamic response which can be accepted in engineering and the fuel consumption can be reduced 21% to compare the original LS excavator and even 32% after adopting another smaller engine.

Energy-Saving Analysis of Hydraulic Hybrid Excavator Based on Common Pressure Rail

PubMed Central

Jiang, Jihai; Su, Xiaoyu

2013-01-01

Energy-saving research of excavators is becoming one hot topic due to the increasing energy crisis and environmental deterioration recently. Hydraulic hybrid excavator based on common pressure rail (HHEC) provides an alternative with electric hybrid excavator because it has high power density and environment friendly and easy to modify based on the existing manufacture process. This paper is focused on the fuel consumption of HHEC and the actuator dynamic response to assure that the new system can save energy without sacrificing performance. Firstly, we introduce the basic principle of HHEC; then, the sizing process is presented; furthermore, the modeling period which combined mathematical analysis and experiment identification is listed. Finally, simulation results show that HHEC has a fast dynamic response which can be accepted in engineering and the fuel consumption can be reduced 21% to compare the original LS excavator and even 32% after adopting another smaller engine. PMID:24194683

Choice of rock excavation method for tramway tunnel in Zurich

NASA Astrophysics Data System (ADS)

Andráskay, E.; Ramer, E.; Berger, E.

1983-02-01

Within the city of Zurich a new tramway line is under construction. One section consists of a tunnel, 350 m long, which is to be built undergound. Different rock excavation methods were evaluated for this tunnel in the light of the many constraints given by the urban environment, such as disturbance of residents in nearby residential houses and closeness of other structures (bridges, road tunnel, university laboratory with vibration-sensitive equipment, etc.). The excavation methods considered were blasting, hydraulic hammer, bulldozer with ripper tooth and mechanical boring with roadheader. The evaluation was made on the basis of vibrations and noise caused by the different excavation methods and on the basis of their respective construction time and cost. Finally the decisions which led to the choice of the excavation method and to the instructions in the tender, documents are presented, and first experiences from the site are discussed.

MONITORING OF PORE WATER PRESSURE AND WATER CONTENT AROUND A HORIZONTAL DRIFT THROUGH EXCAVATION - MEASUREMENT AT THE 140m GALLERY IN THE HORONOBE URL -

NASA Astrophysics Data System (ADS)

Yabuuchi, Satoshi; Kunimaru, Takanori; Kishi, Atsuyasu; Komatsu, Mitsuru

Japan Atomic Energy Agency has been conducting the Horonobe Underground Research Laboratory (URL) project in Horonobe, Hokkaido, as a part of the research and development program on geological disposal of high-level radioactive waste. Pore water pressure and water content around a horizontal drift in the URL have been monitored for over 18 months since before the drift excavation was started. During the drift excavation, both pore water pressure and water content were decreasing. Pore water pressure has been still positive though it continued to decrease with its gradient gradually smaller after excavation, while water content turned to increase about 6 months after the completion of the excavation. It turned to fall again about 5 months later. An unsaturated zone containing gases which were dissolved in groundwater may have been formed around the horizontal drift.

Drill, baby, drill: the influence of woodpeckers on post-fire vertebrate communities through cavity excavation

Treesearch

Gina L. Tarbill; Patricia N. Manley; Angela M. White

2015-01-01

Several studies have addressed the importance of woodpeckers as ecological engineers in forests due to their excavation of cavities. Although research in green, unburned forests has identified the influence of different excavators on secondary use by cavity-dependent species, little is known about the relative importance of cavities created by woodpeckers in recently...

The role of wood hardness in limiting nest site selection in avian cavity excavators

Treesearch

Teresa J. Lorenz; Kerri T. Vierling; Timothy R. Johnson; Philip C. Fischer

2015-01-01

Woodpeckers and other primary cavity excavators (PCEs) are important worldwide for excavating cavities in trees, and a large number of studies have examined their nesting preferences. However, quantitative measures of wood hardness have been omitted from most studies, and ecologists have focused on the effects of external tree- and habitat-level features on nesting....

Characterization of the emissions impacts of hybrid excavators with a portable emissions measurement system (PEMS)-based methodology.

PubMed

Cao, Tanfeng; Russell, Robert L; Durbin, Thomas D; Cocker, David R; Burnette, Andrew; Calavita, Joseph; Maldonado, Hector; Johnson, Kent C

2018-04-13

Hybrid engine technology is a potentially important strategy for reduction of tailpipe greenhouse gas (GHG) emissions and other pollutants that is now being implemented for off-road construction equipment. The goal of this study was to evaluate the emissions and fuel consumption impacts of electric-hybrid excavators using a Portable Emissions Measurement System (PEMS)-based methodology. In this study, three hybrid and four conventional excavators were studied for both real world activity patterns and tailpipe emissions. Activity data was obtained using engine control module (ECM) and global positioning system (GPS) logged data, coupled with interviews, historical records, and video. This activity data was used to develop a test cycle with seven modes representing different types of excavator work. Emissions data were collected over this test cycle using a PEMS. The results indicated the HB215 hybrid excavator provided a significant reduction in tailpipe carbon dioxide (CO 2 ) emissions (from -13 to -26%), but increased diesel particulate matter (PM) (+26 to +27%) when compared to a similar model conventional excavator over the same duty cycle. Copyright © 2018 Elsevier B.V. All rights reserved.

Collective workload organization in confined excavation of granular media

NASA Astrophysics Data System (ADS)

Monaenkova, Daria; Linevich, Vadim; Goodisman, Michael A.; Goldman, Daniel I.

2015-03-01

Many social insects collectively construct large nests in complex substrates; such structures are often composed of narrow tunnels. The benefits of collective construction, including reduced construction costs per worker come with challenges of navigation in crowded, confined spaces. Here we study the workforce organization of groups of S. invicta fire ants creating tunnels in wet granular media. We monitor the activity levels of marked (painted) workers-defined as a number of tunnel visits over 12 hours- during initiation of tunnels. The activity levels are described by a Lorenz curve with a Gini coefficient of ~ 0 . 7 indicating that a majority of the excavation is performed by a minority of workers. We hypothesize that this workload distribution is beneficial for excavation in crowded conditions, and use a 2D cellular automata (CA) model to reproduce behaviors of the excavating ants. CA simulations reveal that tunnel construction rates decrease in groups of equally active animals compared to groups with the natural workload distribution. We use predictions of the CA model to organize collective excavation of granular material by teams of digging robots, and use the robots to test hypotheses of crowded excavation in the physical world. We acknowledge support of National Science Foundation, Physics of Living Systems division.

In Situ Observation of Hard Surrounding Rock Displacement at 2400-m-Deep Tunnels

NASA Astrophysics Data System (ADS)

Feng, Xia-Ting; Yao, Zhi-Bin; Li, Shao-Jun; Wu, Shi-Yong; Yang, Cheng-Xiang; Guo, Hao-Sen; Zhong, Shan

2018-03-01

This paper presents the results of in situ investigation of the internal displacement of hard surrounding rock masses within deep tunnels at China's Jinping Underground Laboratory Phase II. The displacement evolution of the surrounding rock during the entire excavation processes was monitored continuously using pre-installed continuous-recording multi-point extensometers. The evolution of excavation-damaged zones and fractures in rock masses were also observed using acoustic velocity testing and digital borehole cameras, respectively. The results show four kinds of displacement behaviours of the hard surrounding rock masses during the excavation process. The displacement in the inner region of the surrounding rock was found to be greater than that of the rock masses near the tunnel's side walls in some excavation stages. This leads to a multi-modal distribution characteristic of internal displacement for hard surrounding rock masses within deep tunnels. A further analysis of the evolution information on the damages and fractures inside the surrounding rock masses reveals the effects of excavation disturbances and local geological conditions. This recognition can be used as the reference for excavation and supporting design and stability evaluations of hard-rock tunnels under high-stress conditions.

Factors influencing occupancy of nest cavities in recently burned forests

USGS Publications Warehouse

Saab, V.A.; Dudley, J.; Thompson, W.L.

2004-01-01

Recently burned forests in western North America provide nesting habitat for many species of cavity-nesting birds. However, little is understood about the time frame and the variables affecting occupancy of postfire habitats by these birds. We studied factors influencing the occupancy and reuse of nest cavities from 1-7 years after fire in two burned sites of western Idaho during 1994-1999. Tree cavities were used for nesting by 12 species of cavity nesters that were classified by the original occupant (strong excavator, weak excavator, or nonexcavator) of 385 nest cavities. We used logistic regression to model cavity occupancy by strong excavators (n = 575 trials) and weak excavators (n = 206 trials). Year after fire had the greatest influence on occupancy of nest cavities for both groups, while site of the burn was secondarily important in predicting occupancy by strong excavators and less important for weak excavators. Predicted probability of cavity occupancy was highest during the early years (1-4) after fire, declined over time (5-7 years after fire), and varied by site, with a faster decline in the smaller burned site with a greater mosaic of unburned forest. Closer proximity and greater interspersion of unburned forest (15% unburned) may have allowed a quicker recolonization by nest predators into the smaller burn compared to the larger burn with few patches of unburned forest (4% unburned). In combination with time and space effects, the predicted probability of cavity occupancy was positively affected by tree and nest heights for strong and weak excavators, respectively.

Recovery of Missing Persons in Cyprus: Heavy Equipment Methods and Techniques for Complex Well Excavations.

PubMed

Ceker, Deren; Stevens, William D

2015-11-01

This technical note presents the methods and techniques developed by the Bi-communal Forensic Team (BCFT) of the Committee on Missing Persons in Cyprus (CMP) used to excavate and exhume the remains of missing persons, many of whom were buried in deep wells at sites across the island of Cyprus during the conflict period of the 1960s and 1970s. A total of 493 Turkish Cypriots and 1508 Greek Cypriots were officially reported missing by the two communities as a result of the conflict. Since the team's formation, in 2005, the BCFT has excavated 114 wells, resulting in the recovery of 195 missing individuals from 35 of these well excavations. The standard excavation approach used by the BCFT, especially for deep well recovery, consists of "ramp," "pocket," and "pool" components. These excavation features enable CMP archaeologists to excavate deep wells safely and efficiently while simultaneously permitting time for thorough documentation and unimpeded recovery of human remains. The team uses three variants of this approach to cope with the variety of geological, physical, and hydrological contexts faced in Cyprus' wells, including hard and soft landforms, the presence or absence of water, and limitations imposed by surrounding infrastructure. The "terracing", "double-ramp", and "single-ramp" variations are detailed with respect to the environmental contexts which prescribe their use. The BCFT's general procedures for human remains recovery and standard well safety protocols conclude the article. © 2015 American Academy of Forensic Sciences.

Prey capture behavior and kinematics of the Atlantic cownose ray, Rhinoptera bonasus.

PubMed

Sasko, Desirée E; Dean, Mason N; Motta, Philip J; Hueter, Robert E

2006-01-01

The structurally reinforced jaws of the cownose ray, Rhinoptera bonasus testify to this species' durophagous diet of mollusks, but seem ill-suited to the behaviors necessary for excavating such prey. This study explores this discordance by investigating the prey excavation and capture kinematics of R. bonasus. Based on the basal suction feeding mechanism in this group of fishes, we hypothesized a hydraulic method of excavation. As expected, prey capture kinematics of R. bonasus show marked differences relative to other elasmobranchs, relating to prey excavation and use of the cephalic lobes (modified anterior pectoral fin extensions unique to derived myliobatiform rays). Prey are excavated by repeated opening and closing of the jaws to fluidize surrounding sand. The food item is then enclosed laterally by the depressed cephalic lobes, which transport it toward the mouth for ingestion by inertial suction. Unlike in most sharks, upper jaw protrusion and mandibular depression are simultaneous. During food capture, the ray's spiracle, mouth, and gill slit movements are timed such that water enters only the mouth (e.g., the spiracle closes prior to prey capture and reopens immediately following). Indigestible parts are then hydraulically winnowed from edible prey portions, by mouth movements similar to those used in excavation, and ejected through the mouth. The unique sensory/manipulatory capabilities of the cephalic lobes, as well as the cownose ray's hydraulic excavation/winnowing behaviors and suction feeding, make this species an effective benthic predator, despite its epibenthic lifestyle.

A low-cost approach for the documentation and monitoring of an archaeological excavation site

NASA Astrophysics Data System (ADS)

Hoffmeister, Dirk; Orrin, Joel; Richter, Jürgen

2016-04-01

The documentation of archaeological excavations and in particular a constant monitoring is often time-consuming and depending on humańs capabilities. Thus, remote sensing methods, which allow an objective reproduction of the current state of an excavation and additional information are of interest. Therefore, a low-cost approach was tested on an open-air excavation site for two days in September 2015. The Magdalenian excavation site of Bad Kösen-Lengefeld, Germany is one important site in a system of about 100 sites in the area of the small rivers Saale and Unstrut. The whole site and the surrounding area (200 by 200 m) was first observed by a GoPro Hero 3+ mounted on a DJI-Phantom 2 UAV. Ground control points were set-up in a regular grid covering the whole area. The achieved accuracy is 20 mm with a ground resolution of 45 mm. As a test, the GoPro Hero 3+ camera was additionally mounted on a small, extendable pole. With this second low-cost, easy to apply monitoring approach, pictures were automatically taken every second in a stop-and-go mode. In order to capture the excavation pit (7 by 4 m), two different angles were used for holding the pole, which focused on the middle and on the border of the pit. This procedure was repeated on the following day in order to document the excavation process. For the registration of the images, the already existing and measured excavation nails were used, which are equally distributed over the whole site in a 1 m grid. Thus, a high accurate registration of the images was possible (>10 mm). In order to approve the accuracy of the already derived data, the whole site was also observed by a Faro Focus 3D LS 120 laser scanner. The measurements of this device were registered by spherical targets, which were measured in the same reference system. The accuracy of the registration and the ground resolution for the image based approach for both days was about 4 mm. From these two measurements the process of the excavation was easily derived by computing the differences between the point clouds. The mean difference between the laser scanner measurements and the corresponding image observations of about 5 mm proves the overall accuracy. The results show, that the study site can fastly and easily be documented and monitored in a high-resolution by low-cost systems. The approach uses the surveying information of already existing measurements, as tachymetric measurements are usually conducted on nearly all excavation sites. Overall the presented approach worked successfully. The high-resolution dataset allows to easily document the ongoing excavation. A daily observation would lead to a complete documentation in 3D.

Development and demonstration of a telerobotic excavation system

NASA Technical Reports Server (NTRS)

Burks, Barry L.; Thompson, David H.; Killough, Stephen M.; Dinkins, Marion A.

1994-01-01

Oak Ridge National Laboratory is developing remote excavation technologies for the Department of Energy's Office (DOE) of Technology Development, Robotics Technology Development Program, and also for the Department of Defense (DOD) Project Manager for Ammunition Logistics. This work is being done to meet the need for remote excavation and removal of radioactive and contaminated buried waste at several DOE sites and unexploded ordnance at DOD sites. System requirements are based on the need to uncover and remove waste from burial sites in a way that does not cause unnecessary personnel exposure or additional environmental contamination. Goals for the current project are to demonstrate dexterous control of a backhoe with force feedback and to implement robotic operations that will improve productivity. The Telerobotic Small Emplacement Excavator is a prototype system that incorporates the needed robotic and telerobotic capabilities on a commercially available platform. The ability to add remote dexterous teleoperation and robotic operating modes is intended to be adaptable to other commercially available excavator systems.

Preliminary Investigations of the Archaic in the Region of Las Cruces, New Mexico

DTIC Science & Technology

1993-01-01

Excavated in the Jornada Region ................... 110 111-14 Characteristics of Proto-Maiz de Ocho Excavated in the Jornada Region...IlI 111-15 Characteristics of Maiz de Ocho Excavated in the Jornada Region ..................... 112 111-16 Characteristics of Pima-Papago Corn... de - scriptive data that are needed badly in the Southwest so that generalizations can be made about culture change. In Chapter V we attempt to

Big Creek Flood Control Project, Cleveland, Ohio. Phase II. General Design Memorandum. Appendix A. Soils, Geology, and Construction Materials.

DTIC Science & Technology

1979-02-01

maximum thickness of about 4 feet of shale excavation will be required. The upper 1 foot of shale is weathered and easily rippable . A44. From Station...weathered and easily rippable . AS0. From Station 75+60M to 83+50M, maximum excavation in shale is about 3 feet. Most of the excavation in this section will be

Physical soil properties and slope treatments effects on hydraulic excavator productivity for forest road construction.

PubMed

Parsakho, Aidin; Hosseini, Seyed Ataollah; Jalilvand, Hamid; Lotfalian, Majid

2008-06-01

Effects of moisture, porosity and soil bulk density properties, grubbing time and terrain side slopes on pc 220 komatsu hydraulic excavator productivity were investigated in Miana forests road construction project which located in the northern forest of Iran. Soil moisture and porosity determined by samples were taken from undisturbed soil. The elements of daily works were measured with a digital stop watch and video camera in 14 observations (days). The road length and cross section profiles after each 20 m were selected to estimate earthworks volume. Results showed that the mean production rates for the pc 220 komatsu excavators were 60.13 m3 h(-1) and earthwork 14.76 m h(-1) when the mean depth of excavation or cutting was 4.27 m3 m(-1), respectively. There was no significant effects (p = 0.5288) from the slope classes' treatments on productivity, whereas grubbing time, soil moisture, bulk density and porosity had significantly affected on excavator earthworks volume (p < 0.0001). Clear difference was showed between the earthwork length by slope classes (p = 0.0060). Grubbing time (p = 0.2180), soil moisture (p = 0.1622), bulk density (p = 0.2490) and porosity (p = 0.2159) had no significant effect on the excavator earthworks length.

Environmental impacts of forest road construction on mountainous terrain.

PubMed

Caliskan, Erhan

2013-03-15

Forest roads are the base infrastructure foundation of forestry operations. These roads entail a complex engineering effort because they can cause substantial environmental damage to forests and include a high-cost construction. This study was carried out in four sample sites of Giresun, Trabzon(2) and Artvin Forest Directorate, which is in the Black Sea region of Turkey. The areas have both steep terrain (30-50% gradient) and very steep terrain (51-80% gradient). Bulldozers and hydraulic excavators were determined to be the main machines for forest road construction, causing environmental damage and cross sections in mountainous areas.As a result of this study, the percent damage to forests was determined as follows: on steep terrain, 21% of trees were damaged by excavators and 33% of trees were damaged by bulldozers during forest road construction, and on very steep terrain, 27% of trees were damaged by excavators and 44% of trees were damaged by bulldozers during forest road construction. It was also determined that on steep terrain, when excavators were used, 12.23% less forest area was destroyed compared with when bulldozers were used and 16.13% less area was destroyed by excavators on very steep terrain. In order to reduce the environmental damage on the forest ecosystem, especially in steep terrains, hydraulic excavators should replace bulldozers in forest road construction activities.

Numerical Simulation of Rock Mass Damage Evolution During Deep-Buried Tunnel Excavation by Drill and Blast

NASA Astrophysics Data System (ADS)

Yang, Jianhua; Lu, Wenbo; Hu, Yingguo; Chen, Ming; Yan, Peng

2015-09-01

Presence of an excavation damage zone (EDZ) around a tunnel perimeter is of significant concern with regard to safety, stability, costs and overall performance of the tunnel. For deep-buried tunnel excavation by drill and blast, it is generally accepted that a combination of effects of stress redistribution and blasting is mainly responsible for development of the EDZ. However, few open literatures can be found to use numerical methods to investigate the behavior of rock damage induced by the combined effects, and it is still far from full understanding how, when and to what degree the blasting affects the behavior of the EDZ during excavation. By implementing a statistical damage evolution law based on stress criterion into the commercial software LS-DYNA through its user-subroutines, this paper presents a 3D numerical simulation of the rock damage evolution of a deep-buried tunnel excavation, with a special emphasis on the combined effects of the stress redistribution of surrounding rock masses and the blasting-induced damage. Influence of repeated blast loadings on the damage extension for practical millisecond delay blasting is investigated in the present analysis. Accompanying explosive detonation and secession of rock fragments from their initial locations, in situ stress in the immediate vicinity of the excavation face is suddenly released. The transient characteristics of the in situ stress release and induced dynamic responses in the surrounding rock masses are also highlighted. From the simulation results, some instructive conclusions are drawn with respect to the rock damage mechanism and evolution during deep-buried tunnel excavation by drill and blast.

Hydromechanical Advanced Coal Excavator

NASA Technical Reports Server (NTRS)

Estus, Jay M.; Summers, David

1990-01-01

Water-jet cutting reduces coal dust and its hazards. Advanced mining system utilizes full-face, hydromechanical, continuous miner. Coal excavator uses high-pressure water-jet lances, one in each of cutting heads and one in movable lance, to make cuts across top, bottom and middle height, respectively, of coal face. Wedge-shaped cutting heads advance into lower and upper cuts in turn, thereby breaking coal toward middle cut. Thrust cylinders and walking pads advance excavator toward coal face.

A New Conception of Bucket Wheel Excavator Cab and Seat Mounting

NASA Astrophysics Data System (ADS)

Blekta, J.; Mevald, J.; Petríková, I.; Petříček, J.; Lufinka, A.

One of the most important problem of coal mining by bucket wheel excavators is how to minimize influence of vibrations on driver's body. Project of Ministry of Trade and Industry of the Czech Republic solved in Technical University of Liberec was engaged in this problem. The aim of this project was to design a new cab and seat mounting of wheel excavator Schrs 1320. A suitable possibilities of cab suspensions were investigated to minimize driver body vibrations and to improve influence of mining process to drivers health. After optimization one concept was chosen. A new methodic of measured data evaluation was created for using in excavators as well as in laboratory. The new concept of dynamic seat absorber were designed also.

Lunar Regolith Excavation Competition

NASA Technical Reports Server (NTRS)

Liles, Cassandra

2009-01-01

The Lunar Regolith Excavation Competition is a new competition that needs graphics, logos, rules, as well as an arena. Although this is the first year of the competition, the competition is modeled after an existing competition, the Centennial Lunar Excavator Challenge. This competition however is aimed at college students. This makes the challenge identifying key aspects of the original competition and modeling them to fit into an easier task, and creating exciting advertisement that helps encourage participation. By using a youth focus group, young insight, as well as guiding advice from experts in the field, hopefully an arena can be designed and built, rules can be molded and created to fit, and alluring graphics can be printed to bring about a successful first year of the Lunar Regolith Excavation Competition.

Mobile continuous lunar excavation

NASA Technical Reports Server (NTRS)

Paterson, John L.

1992-01-01

A novel approach to the concept of lunar mining and the use of in situ oxygen, metallics, and ceramics is presented. The EVA time required to set up, relocate, and maintain equipment, as well as the cost per pound of shipping the mining and processing equipment to the moon are considered. The proposed soil fracturing/loading mechanisms are all based loosely on using the Apollo Lunar Roving Vehicle (LRV) Frame. All use motor driven tracks for mobility in the forward/reverse and left/right direction. All mechanisms employ the concept of rototillers which are attached to a gantry which, through the use of motor-driven lead screws, provide the rototillers with an up/down capability. A self-reactant excavator, a local mass enhanced excavator, and a soil reactant excavator are illustrated.

Lunar construction/mining equipment

NASA Technical Reports Server (NTRS)

Ozdemir, Levent

1990-01-01

For centuries, mining has utilized drill and blast as the primary method of rock excavation. Although this technique has undergone significant improvements, it still remains a cyclic, labor intensive operation with inherent safety hazards. Other drawbacks include damage to the surrounding ground, creation of blast vibrations, rough excavation walls resulting in increased ventilation requirements, and the lack of selective mining ability. Perhaps the most important shortcoming of drill and blast is that it is not conducive to full implementation of automation or robotics technologies. Numerous attempts have been made in the past to automate drill and blast operations to remove personnel from the hazardous work environment. Although most of the concepts devised look promising on paper, none of them was found workable on a sustained production basis. In particular, the problem of serious damage to equipment during the blasting cycle could not be resolved regardless of the amount of charge used in excavation. Since drill and blast is not capable of meeting the requirements of a fully automated rock fragmentation method, its role is bound to gradually decrease. Mechanical excavation, in contrast, is highly suitable to automation because it is a continuous process and does not involve any explosives. Many of the basic principles and trends controlling the design of an earth-based mechanical excavator will hold in an extraterrestrial environment such as on the lunar surface. However, the economic and physical limitations for transporting materials to space will require major rethinking of these machines. In concept, then, a lunar mechanical excavator will look and perform significantly different from one designed for use here on earth. This viewgraph presentation gives an overview of such mechanical excavator systems.

BILATERAL CHOROIDAL EXCAVATION IN JUVENILE LOCALIZED SCLERODERMA.

PubMed

Franklin, Mackenzie L; Day, Shelley

2018-01-01

To describe a case of bilateral choroidal excavation in a patient with juvenile localized scleroderma. Case report. An asymptomatic 12-year-old boy with localized scleroderma presented for examination and was found to have bilateral areas of choroidal excavation temporal to the fovea. Previous reports of ocular complications of localized scleroderma have primarily described adnexal and anterior segment changes. This is the second report of choroidal changes in a patient with localized scleroderma, and the first in a pediatric patient.

Consumption of pondweed rhizomes by Yellowstone grizzly bears

USGS Publications Warehouse

Mattson, D.J.; Podruzny, S.R.; Haroldson, M.A.

2005-01-01

Pondweeds (Potamogeton spp.) are common foods of waterfowl throughout the Northern Hemisphere. However, consumption of pondweeds by bears has been noted only once, in Russia. We documented consumption of pondweed rhizomes by grizzly bears (Ursus arctos) in the Yellowstone region, 1977-96, during investigations of telemetry locations obtained from 175 radiomarked bears. We documented pondweed excavations at 25 sites and detected pondweed rhizomes in 18 feces. We observed grizzly bears excavating and consuming pondweed on 2 occasions. All excavations occurred in wetlands that were inundated during and after snowmelt, but dry by late August or early September of most years. These wetlands were typified by the presence of inflated sedge (Carex vesicaria) and occurred almost exclusively on plateaus of Pliocene-Pleistocene detrital sediments or volcanic rhyolite flows. Bears excavated wetlands with pondweeds when they were free of standing water, most commonly during October and occasionally during spring prior to the onset of terminal snowmelt. Most excavations were about 4.5 cm deep, 40 cubic decimeter (dm3) in total volume, and targeted the thickened pondweed rhizomes. Starch content of rhizomes collected near grizzly bear excavations averaged 28% (12% SD; n = 6). These results add to the documented diversity of grizzly bear food habits and, because pondweed is distributed circumboreally, also raise the possibility that consumption of pondweed by grizzly bears has been overlooked in other regions.

Monitoring of Deformation in Ground Before and After Tunnel Excavation

NASA Astrophysics Data System (ADS)

Eren, Mehmet; Hilmi Erkoç, Muharrem

2017-04-01

As population increase in metropolitan city, we need transportation and transmission tunnel. In this context, the engineers and administors attach impotance to building and planning underground-tunnel. Moreover, we must at regular intervals monitoring to deformation in underground-tunnel for quality and safety. Firstly, a deformation monitoring network is designed as perpendicular to the tunnel main axis. Secondly, the prescribed number of deformation measurements must be made. Finally, the deformation analysis is evaluated and its results is interpreted. This study investigates how deformation in monitoring network during and after tunnel excavate change.For this purpose, a deformation monitoring network of 18 object point and 4 reference point was established. Object points networks was designed steeply to the tunnel main axis as 3 cross section. Each cross section consisted of 3 point left, 2 point right and 1 point at the flowing line. Initial conditional measurement was made before tunnel excavation. Then the deformation measurement was made 5 period (1 period measured after tunnel excavate). All data sets were adjusted according to free adjustment method. The results from the investigation considering the tunnel line, a symmetrical subsidence was observed. The following day of tunnel excavation, we were observed %68 per of the total deformation. At the end of the last period measurements, %99 per of the total deformation was detected. Keywords: Tunnel, Deformation, Subsidence, Excavation

Environmental impacts of forest road construction on mountainous terrain

PubMed Central

2013-01-01

Forest roads are the base infrastructure foundation of forestry operations. These roads entail a complex engineering effort because they can cause substantial environmental damage to forests and include a high-cost construction. This study was carried out in four sample sites of Giresun, Trabzon(2) and Artvin Forest Directorate, which is in the Black Sea region of Turkey. The areas have both steep terrain (30-50% gradient) and very steep terrain (51-80% gradient). Bulldozers and hydraulic excavators were determined to be the main machines for forest road construction, causing environmental damage and cross sections in mountainous areas. As a result of this study, the percent damage to forests was determined as follows: on steep terrain, 21% of trees were damaged by excavators and 33% of trees were damaged by bulldozers during forest road construction, and on very steep terrain, 27% of trees were damaged by excavators and 44% of trees were damaged by bulldozers during forest road construction. It was also determined that on steep terrain, when excavators were used, 12.23% less forest area was destroyed compared with when bulldozers were used and 16.13% less area was destroyed by excavators on very steep terrain. In order to reduce the environmental damage on the forest ecosystem, especially in steep terrains, hydraulic excavators should replace bulldozers in forest road construction activities. PMID:23497078

Mitigating clogging and arrest in confined self-propelled systems

NASA Astrophysics Data System (ADS)

Savoie, William; Aguilar, Jeffrey; Monaenkova, Daria; Linevich, Vadim; Goldman, Daniel

Ensembles of self-propelling elements, like colloidal surfers, bacterial biofilms, and robot swarms can spontaneously form density heterogeneities. To understand how to prevent potentially catastrophic clogs in task-oriented active matter systems (like soil excavating robots), we present a robophysical study of excavation of granular media in a confined environment. We probe the efficacy of two social strategies observed in our studies of fire ants (S. invicta). The first behavior (denoted as unequal workload) prescribes to each excavator a different probability to enter the digging area. The second behavior (denoted as reversal\\x9D), is characterized by a probability to forfeit excavation when progress is sufficiently obstructed. For equal workload distribution and no reversal behavior, clogs at the digging site prevent excavation for sufficient numbers of robots. Measurements of aggregation relaxation times reveal how the strategies mitigate clogs. The unequal workload behavior reduces the tunnel density, decreasing the probability of clog formation. Reversal behavior, while allowing clogs to form, reduces aggregation relaxation time. We posit that application of social behaviors can be useful for swarm robot systems where global control and organization may not be possible.

Numerical Simulation and Monitoring of Surface Environment Influence of Waterless Sand Layer Shield Tunneling

NASA Astrophysics Data System (ADS)

Shang, Yanliang; Han, Tongyin; Shi, Wenjun; Du, Shouji; Qin, Zhichao

2017-10-01

The development of urban subway is becoming more and more rapid and plays an increasingly important role. The shield tunneling method has become the first choice for the construction of urban subway tunnel in the construction of urban subway. The paper takes the interval of Shijiazhuang Metro Line 3 Administrative Center Station and Garden Park Station as the engineering background. The establishment of double shield finite difference model by considering the thickness of covering soil, tunnel excavation and excavation at the same time, distance and other factors, the surface deformation, and soil thickness. The ground deformation law is obtained, the surface settlement is inversely proportional to the overburden thickness and the double line spacing, and the gradual excavation is smaller than the synchronous excavation.

Experimental research data on stress state of salt rock mass around an underground excavation

NASA Astrophysics Data System (ADS)

Baryshnikov, VD; Baryshnikov, DV

2018-03-01

The paper presents the experimental stress state data obtained in surrounding salt rock mass around an excavation in Mir Mine, ALROSA. The deformation characteristics and the values of stresses in the adjacent rock mass are determined. Using the method of drilling a pair of parallel holes in a stressed area, the authors construct linear relationship for the radial displacements of the stress measurement hole boundaries under the short-term loading of the perturbing hole. The resultant elasticity moduli of rocks are comparable with the laboratory core test data. Pre-estimates of actual stresses point at the presence of a plasticity zone in the vicinity of the underground excavation. The stress state behavior at a distance from the excavation boundary disagrees with the Dinnik–Geim hypothesis.

Quantifying Contaminant Mass for the Feasibility Study of the DuPont Chambers Works FUSRAP Site - 13510

DOE Office of Scientific and Technical Information (OSTI.GOV)

Young, Carl; Rahman, Mahmudur; Johnson, Ann

2013-07-01

The U.S. Army Corps of Engineers (USACE) - Philadelphia District is conducting an environmental restoration at the DuPont Chambers Works in Deepwater, New Jersey under the Formerly Utilized Sites Remedial Action Program (FUSRAP). Discrete locations are contaminated with natural uranium, thorium-230 and radium-226. The USACE is proposing a preferred remedial alternative consisting of excavation and offsite disposal to address soil contamination followed by monitored natural attenuation to address residual groundwater contamination. Methods were developed to quantify the error associated with contaminant volume estimates and use mass balance calculations of the uranium plume to estimate the removal efficiency of the proposedmore » alternative. During the remedial investigation, the USACE collected approximately 500 soil samples at various depths. As the first step of contaminant mass estimation, soil analytical data was segmented into several depth intervals. Second, using contouring software, analytical data for each depth interval was contoured to determine lateral extent of contamination. Six different contouring algorithms were used to generate alternative interpretations of the lateral extent of the soil contamination. Finally, geographical information system software was used to produce a three dimensional model in order to present both lateral and vertical extent of the soil contamination and to estimate the volume of impacted soil for each depth interval. The average soil volume from all six contouring methods was used to determine the estimated volume of impacted soil. This method also allowed an estimate of a standard deviation of the waste volume estimate. It was determined that the margin of error for the method was plus or minus 17% of the waste volume, which is within the acceptable construction contingency for cost estimation. USACE collected approximately 190 groundwater samples from 40 monitor wells. It is expected that excavation and disposal of contaminated soil will remove the contaminant source zone and significantly reduce contaminant concentrations in groundwater. To test this assumption, a mass balance evaluation was performed to estimate the amount of dissolved uranium that would remain in the groundwater after completion of soil excavation. As part of this evaluation, average groundwater concentrations for the pre-excavation and post-excavation aquifer plume area were calculated to determine the percentage of plume removed during excavation activities. In addition, the volume of the plume removed during excavation dewatering was estimated. The results of the evaluation show that approximately 98% of the aqueous uranium would be removed during the excavation phase. The USACE expects that residual levels of contamination will remain in groundwater after excavation of soil but at levels well suited for the selection of excavation combined with monitored natural attenuation as a preferred alternative. (authors)« less

Modeling and stability of electro-hydraulic servo of hydraulic excavator

NASA Astrophysics Data System (ADS)

Jia, Wenhua; Yin, Chenbo; Li, Guo; Sun, Menghui

2017-11-01

The condition of the hydraulic excavator is complicated and the working environment is bad. The safety and stability of the control system is influenced by the external factors. This paper selects hydraulic excavator electro-hydraulic servo system as the research object. A mathematical model and simulation model using AMESIM of servo system is established. Then the pressure and flow characteristics are analyzed. The design and optimization of electro-hydraulic servo system and its application in engineering machinery is provided.

Asteroid Icy Regolith Excavation and Volatile Capture Project

NASA Technical Reports Server (NTRS)

Zeitlin, Nancy; Mantovani, James; Swanger, Adam; Townsend, Ivan

2015-01-01

Icy regolith simulants will be produced in a relevant vacuum environment using various minerals, including hydrated minerals, that are found in C-type meteorites and in other types of planetary regolith. This will allow us to characterize the mechanical strength of the icy regolith as a function of ice content using penetration, excavation, and sample capture devices. The results of this study will benefit engineers in designing efficient regolith excavators and ISRU processing systems for future exploration missions to asteroids and other planetary bodies.

Pajarito Plateau archaeological surveys and excavations. II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steen, C R

1982-04-01

Los Alamos National Laboratory continues its archaeological program of data gathering and salvage excavations. Sites recently added to the archaeological survey are described, as well as the results of five excavations. Among the more interesting and important discoveries are (1) the apparently well-established local use of anhydrous lime, and (2) a late pre-Columbian use of earlier house sites and middens for garden plots. Evidence indicated that the local puebloan population was the result of an expansion of upper Rio Grande peoples, not an influx of migrants.

49 CFR 195.442 - Damage prevention program.

Code of Federal Regulations, 2011 CFR

2011-10-01

... of this section, the term “excavation activities” includes excavation, blasting, boring, tunneling... by paragraph (a) of this section must, at a minimum: (1) Include the identity, on a current basis, of...

49 CFR 195.442 - Damage prevention program.

Code of Federal Regulations, 2014 CFR

2014-10-01

... of this section, the term “excavation activities” includes excavation, blasting, boring, tunneling... by paragraph (a) of this section must, at a minimum: (1) Include the identity, on a current basis, of...

49 CFR 195.442 - Damage prevention program.

Code of Federal Regulations, 2010 CFR

2010-10-01

... of this section, the term “excavation activities” includes excavation, blasting, boring, tunneling... by paragraph (a) of this section must, at a minimum: (1) Include the identity, on a current basis, of...

49 CFR 195.442 - Damage prevention program.

Code of Federal Regulations, 2012 CFR

2012-10-01

... of this section, the term “excavation activities” includes excavation, blasting, boring, tunneling... by paragraph (a) of this section must, at a minimum: (1) Include the identity, on a current basis, of...

49 CFR 195.442 - Damage prevention program.

Code of Federal Regulations, 2013 CFR

2013-10-01

... of this section, the term “excavation activities” includes excavation, blasting, boring, tunneling... by paragraph (a) of this section must, at a minimum: (1) Include the identity, on a current basis, of...

Material Excavated by a Fresh Impact and Identified as Water Ice

NASA Image and Video Library

2009-09-24

The Compact Reconnaissance Imaging Spectrometer for Mars, an instrument on NASA Mars Reconnaissance Orbiter, obtained information confirming material excavated by a fresh impact and Identified as water ice.

16. TAILRACE ARCH FROM 1814 MILL BROKEN THROUGH DURING EXCAVATION ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

16. TAILRACE ARCH FROM 1814 MILL BROKEN THROUGH DURING EXCAVATION FOR A SURFACE WATER RUNOFF POLLUTION TRAP, SUBSEQUENTLY FILLED. - Boston Manufacturing Company, 144-190 Moody Street, Waltham, Middlesex County, MA

Multi-layer waste containment barrier

DOEpatents

Smith, Ann Marie; Gardner, Bradley M.; Nickelson, David F.

1999-01-01

An apparatus for constructing an underground containment barrier for containing an in-situ portion of earth. The apparatus includes an excavating device for simultaneously (i) excavating earthen material from beside the in-situ portion of earth without removing the in-situ portion and thereby forming an open side trench defined by opposing earthen sidewalls, and (ii) excavating earthen material from beneath the in-situ portion of earth without removing the in-situ portion and thereby forming a generally horizontal underground trench beneath the in-situ portion defined by opposing earthen sidewalls. The apparatus further includes a barrier-forming device attached to the excavating device for simultaneously forming a side barrier within the open trench and a generally horizontal, multi-layer barrier within the generally horizontal trench. The multi-layer barrier includes at least a first layer and a second layer.

Silica exposure to excavation workers during the excavation of a low level radiological waste pit and tritium disposal shafts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, K.M.

1995-01-01

This study evaluated the task-length average (TLA) respirable dust and respirable silica airborne concentrations to which construction workers excavating volcanic tuff at Los Alamos National Laboratory (LANL) were exposed. These workers were excavating a low level radiological waste disposal pit of final dimensions 720 feet long, 132 feet wide and 60 feet deep. The objectives of this study were as follows: (1) evaluate exposures; (2) determine if the type of machinery used affects the respirable dust concentration in the breathing zone of the worker; (3) evaluate the efficacy of wetting the pit to reduce the respirable dust exposure; and (4)more » determine if exposure increases with increasing depth of pit due to the walls of the pit blocking the cross wind ventilation.« less

A study on the dynamic behavior of the Meuse/Haute-Marne argillite

NASA Astrophysics Data System (ADS)

Cai, M.; Kaiser, P. K.; Suorineni, F.; Su, K.

Excavation of underground tunnels can be conducted by tunnel boring machines (TBM) or drill-and-blast. TBMs cause minimum damage to excavation walls. Blasting effects on excavation walls depend on the care with which the blasting is executed. For blast-induced damage in excavation walls, two issues have to be addressed: rate of loss of confinement (rate of excavation) and dynamic loading from wave propagation that causes both intended and unintended damage. To address these two aspects, laboratory dynamic tests were conducted for the determination of the dynamic properties of the Meuse/Haute-Marne argillite. In the present study, 17 tensile (Brazilian) and 15 compression split Hopkinson pressure bar (SHPB) tests were conducted. The test revealed that the dynamic strengths of the argillite are strain rate dependent. The average dynamic increase factors (ratio of dynamic strength to static strength) for tensile and compressive strength are about 3.3 and 2.4, respectively. A high-speed video camera was used to visualize the initiation of failure and subsequent deformation of the specimens. The direct compression specimens were found to deform and fail uniformly around the circumference of the specimen, by a spalling process. The SHPB Brazilian tests indicated that failure occurred in tension along the line of load application. Radial fractures were also observed. The test results can be used for the development of a dynamic constitutive model for the argillite for the prediction of damage in underground excavation utilizing the drill-and blast method.

Physico-chemical properties of excavated plastic from landfill mining and current recycling routes.

PubMed

Canopoli, L; Fidalgo, B; Coulon, F; Wagland, S T

2018-06-01

In Europe over 5.25 billion tonnes of waste has been landfilled between 1995 and 2015. Among this large amount of waste, plastic represents typically 5-25 wt% which is significant and has the potential to be recycled and reintroduced into the circular economy. To date there is still however little information available of the opportunities and challenges in recovering plastics from landfill sites. In this review, the impacts of landfill chemistry on the degradation and/or contamination of excavated plastic waste are analysed. The feasibility of using excavated plastic waste as feedstock for upcycling to valuable chemicals or liquid fuels through thermochemical conversion is also critically discussed. The limited degradation that is experienced by many plastics in landfills (>20 years) which guarantee that large amount is still available is largely due to thermooxidative degradation and the anaerobic conditions. However, excavated plastic waste cannot be conventionally recycled due to high level of ash, impurities and heavy metals. Recent studies demonstrated that pyrolysis offers a cost effective alternative option to conventional recycling. The produced pyrolysis oil is expected to have similar characteristics to petroleum diesel oil. The production of valuable product from excavated plastic waste will also increase the feasibility of enhanced landfill mining projects. However, further studies are needed to investigate the uncertainties about the contamination level and degradation of excavated plastic waste and address their viability for being processed through pyrolysis. Copyright © 2018 Elsevier Ltd. All rights reserved.

Deep Fracturing of the Hard Rock Surrounding a Large Underground Cavern Subjected to High Geostress: In Situ Observation and Mechanism Analysis

NASA Astrophysics Data System (ADS)

Feng, Xia-Ting; Pei, Shu-Feng; Jiang, Quan; Zhou, Yang-Yi; Li, Shao-Jun; Yao, Zhi-Bin

2017-08-01

Rocks that are far removed from caverns or tunnels peripheries and subjected to high geostress may undergo `deep fracturing'. Deep fracturing of hard rock can cause serious hazards that cause delays and increase the cost of construction of underground caverns with high sidewalls and large spans (especially when subjected to high geostress). To extensively investigate the mechanism responsible for deep fracturing, and the relationship between fracturing and the excavation & support of caverns, this paper presents a basic procedure for making in situ observations on the deep fracturing process in hard rock. The basic procedure involves predicting the stress concentration zones in the surrounding rocks of caverns induced by excavation using geomechanical techniques. Boreholes are then drilled through these stress concentration zones from pre-existing tunnels (such as auxiliary galleries) toward the caverns before its excavation. Continuous observations of the fracturing of the surrounding rocks are performed during excavation using a borehole camera in the boreholes in order to analyze the evolution of the fracturing process. The deep fracturing observed in a large underground cavern (high sidewalls and large span) in southwest China excavated in basalt under high geostress is also discussed. By continuously observing the hard rock surrounding the arch on the upstream side of the cavern during the excavation of the first three layers, it was observed that the fracturing developed into the surrounding rocks with downward excavation of the cavern. Fracturing was found at distances up to 8-9 m from the cavern periphery during the excavation of Layer III. Also, the cracks propagated along pre-existing joints or at the interfaces between quartz porphyry and the rock matrix. The relationship between deep fracturing of the surrounding rocks and the advance of the cavern working faces was analyzed during excavation of Layer Ib. The results indicate that the extent of the stress relief zone is about 7 m if footage of 3 m is adopted for the rate of advance of the cavern faces. An analysis of the effects of the initial geostress and evolving stress concentration on deep fracturing was also made. It could be concluded that the deep fracturing of the rocks in the upstream side of the cavern is caused by the combined effect of the high initial geostress, the transfer of the stress concentration zone toward the deep surrounding rocks, and the occurrence of discontinuities.

Damage initiation and propagation assessed from stress-induced microseismic events during a mine-by test in the Opalinus Clay

NASA Astrophysics Data System (ADS)

Le Gonidec, Y.; Sarout, J.; Wassermann, J.; Nussbaum, C.

2014-07-01

We report in this paper an original analysis of microseismic events (MSEs) induced by an excavation operation in the clay environment of the Mont Terri underground rock laboratory. In order to identify the MSEs with confidence, we develop a restrictive but efficient multistep method for filtering the recorded events. We deduce the spatial distribution and processes associated with the excavation-induced damage from the spatial location and focal mechanisms of the MSEs. We observe an asymmetric geometry of the excavation damaged zone around the excavated gallery, without notable microseismic activity in the sandy facies sidewall, in contrast with the shaly facies sidewall where a first burst of events is recorded, followed by two smaller bursts: one locates ahead of the excavation front and is associated with a dominant double-couple component, suggesting bedding plane reworking, that is, shear fracture mode, and the MSEs of the other cluster inside the shaly sidewall of the gallery, with a dominant compensated linear vector dipole component, suggesting extensive cracking. We identify and discuss four major factors that seem to control the MSEs source mechanisms: lithology, geometry of the geological features, gallery orientation and direction of the main compressive stress.

Behavior of braced excavation in sand under a seismic condition: experimental and numerical studies

NASA Astrophysics Data System (ADS)

Konai, Sanku; Sengupta, Aniruddha; Deb, Kousik

2018-04-01

The behavior of braced excavation in dry sand under a seismic condition is investigated in this paper. A series of shake table tests on a reduced scale model of a retaining wall with one level of bracing were conducted to study the effect of different design parameters such as excavation depth, acceleration amplitude and wall stiffness. Numerical analyses using FLAC 2D were also performed considering one level of bracing. The strut forces, lateral displacements and bending moments in the wall at the end of earthquake motion were compared with experimental results. The study showed that in a post-seismic condition, when other factors were constant, lateral displacement, bending moment, strut forces and maximum ground surface displacement increased with excavation depth and the amplitude of base acceleration. The study also showed that as wall stiffness decreased, the lateral displacement of the wall and ground surface displacement increased, but the bending moment of the wall and strut forces decreased. The net earth pressure behind the walls was influenced by excavation depth and the peak acceleration amplitude, but did not change significantly with wall stiffness. Strut force was the least affected parameter when compared with others under a seismic condition.

Endoscopic excavation for the treatment of small esophageal subepithelial tumors originating from the muscularis propria.

PubMed

Ye, Li-ping; Zhu, Lin-hong; Zhou, Xian-bin; Mao, Xin-li; Zhang, Yu

2015-01-01

This study was designed to evaluate the safety and efficacy of endoscopic excavation for esophageal subepithelial tumors originating from the muscularis propria. Forty-five patients with esophageal subepithelial tumors originating from the muscularis propria were treated with endoscopic excavation between January 2010 and June 2012. The key steps were: (1) making several dots around the tumor; (2) incising the mucosa along with the marker dots, and then seperating the tumor from the muscularis propria by using a hook knife or an insulated-tip knife; (3) closing the artificial ulcer with clips after the tumor was removed. The mean tumor diameter was 1.1 ± 0.6 cm. Endoscopic excavation was successfully performed in 43 out of 45 cases (95.6%), the other 2 cases were ligated with nylon rope. During the procedure perforation occurred in 4 (8.9%) patients, who recovered after conservative treatment. No massive bleeding or delayed bleeding occurred. Histologic diagnosis was obtained from 43 (95.6%) patients. Pathological diagnoses of these tumors were leiomyomas (38/43) and gastrointestinal stromal tumors (5/43). Endoscopic excavation is a safe and effective method for the treatment of small esophageal subepithelial tumors originating from the muscularis propria.

4. VIEW OF AREA EXCAVATED FOR ACCESS TO MERCURY RETORT. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. VIEW OF AREA EXCAVATED FOR ACCESS TO MERCURY RETORT. VIEW SOUTH FROM RETORT. (OCTOBER, 1995) - McCormick Group Mine, Mercury Retort, East slope of Buckskin Mountain, Paradise Valley, Humboldt County, NV

Navy Pier roundabout, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation during the excavation process did not exceed theinstrument threshold previously stated, and ranged from a minimum of 2,300 cpm to a maximum of 4,300cpm unshielded.

305 E. Erie Street, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation during the excavation process did not exceed theinstrument threshold previously stated, and ranged from a minimum of 1,900 cpm to a maximum of 3,900cpm unshielded.

400-420 N St Clair St, May 2014, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation and the spoil materials generatedduring the excavation process did not exceed the respective instrument threshold previously stated witha maximum of 8,000 cpm unshielded.

301-45 E Illinois St, May 2014, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation and the spoil materials generatedduring the excavation process did not exceed the respective instrument threshold previously stated with amaximum of 7,500 cpm unshielded.

215 E. Grand Ave, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation during the excavation process did not exceed theinstrument threshold previously stated, and ranged from a minimum of 1,300 cpm to a maximum of 3,500cpm shielded.

18 CFR 1304.207 - Channel excavation on TVA-owned residential access shoreland.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Resources TENNESSEE VALLEY AUTHORITY APPROVAL OF CONSTRUCTION IN THE TENNESSEE RIVER SYSTEM AND REGULATION... the reservoir bottom is exposed and dry. (h) Spoil material from channel excavations must be placed in...

41. Upstream end of emergency spillway excavation. Photographer unknown, 1929. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

41. Upstream end of emergency spillway excavation. Photographer unknown, 1929. Source: Arizona Department of Water Resources (ADWR). - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

Calculation of Excavation Force for ISRU on Lunar Surface

NASA Technical Reports Server (NTRS)

Zeng, Xiangwu (David); Burnoski, Louis; Agui, Juan H.; Wilkinson, Allen

2007-01-01

Accurately predicting the excavation force that will be encountered by digging tools on the lunar surface is a crucial element of in-situ resource utilization (ISRU). Based on principles of soil mechanics, this paper develops an analytical model that is relatively simple to apply and uses soil parameters that can be determined by traditional soil strength tests. The influence of important parameters on the excavation force is investigated. The results are compared with that predicted by other available theories. Results of preliminary soil tests on lunar stimulant are also reported.

Analysis of rockbolt performance at the Waste Isolation Pilot Plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Terrill, L.J.; Francke, C.T.; Saeb, S.

Rockbolt failures at the Waste Isolation Pilot Plant have been recorded since 1990 and are categorized in terms of mode of failure. The failures are evaluated in terms of physical location of installation within the mine, local excavation geometry and stratigraphy, proximity to other excavations or shafts, and excavation age. The database of failures has revealed discrete ares of the mine containing relatively large numbers of failures. The results of metallurgical analyses and standard rockbolt load testing have generally been in agreement with the in situ evaluations.

Excavation of red squirrel middens by grizzly bears in the whitebark pine zone

USGS Publications Warehouse

Mattson, D.J.; Reinhart, Daniel P.

1997-01-01

Whitebark pine seeds Pinus albicaulis are an important food of grizzly Ursus arctos horribilis bears wherever whitebark pine is abundant in the contiguous United States of America; availability of seeds affects the distribution of bears, and the level of conflict between bears and humans. Almost all of the seeds consumed by bears are excavated from middens where red squirrels Tamiasciurus hudsonicus have cached whitebark pine cones.Relationships among the occupancy of middens by squirrels, the excavation of middens by bears, and site features were investigated in this study. Data were collected from radio-marked bears and from middens located from line transects on two study sites in the Yellowstone ecosystem.Densities of active middens were positively related to lodgepole pine Pinus contorta basal area and negatively related to steepness of slope.The probability that a midden was occupied by a squirrel (i.e. active) was positively related to lodgepole pine basal area in the surrounding stand, size of the midden and size of the whitebark pine cone crop, and negatively related to elevation and to bear excavation during the previous 2-12 months.The probability that a midden had been excavated by a bear during the previous 12 months was positively related to size of the midden, and to whitebark pine basal area and cone crop, and negatively related to nearness of roads and town sites.The influence of midden size on bear use was attributable to a positive relationship with the number of excavated cones. The positive association between bear excavations and whitebark pine basal area or cone crops was attributable to availability of pine seeds.Grizzly bears would benefit from the minimization of roads and other human facilities in the whitebark pine zone and from increases in the availability of whitebark pine seeds, potentially achieved by increasing the numbers of cone-producing whitebark pine trees, especially in lower elevations of the whitebark pine zone where red squirrels are more abundant.

A Review of Lunar Regolith Excavation Robotic Device Prototypes

NASA Technical Reports Server (NTRS)

Mueller, Robert P.; Van Susante, Paul J.

2011-01-01

The excavation of lunar regolith is desirable for use as a feedstock for oxygen production processes as well as civil engineering purposes and for the fabrication of parts and structures. This is known as In-Situ Resource Utilization (ISRU). More recently, there has been mounting evidence that water ice exists at the poles of the Moon, buried in the regolith where thermally stable conditions exist. This means that regolith excavation will be required to mine the water ice which is believed to be. mixed in with the regolith, or bonded to it. The mined water ice can then be electrolyzed to produce hydrogen and oxygen propellants which could form the basis of a cis-lunar transportation system using in-situ derived propellants. In 2007, the National Aeronautics & Space Administration (NASA) sponsored a Lunar Regolith Excavation Competition as part of its Centennial Challenges program, The competition was not won and it was held again in 2008 and 2009, when it was won by a university team. A $500,000 prize was awarded to the winning team by NASA. In 2010, NASA continued the competition as a spinoff of the Centennial Challenges, which is restricted to university participation only. This competition is known as the "Lunabotics Mining Competition" and is hosted by NASA at Kennedy Space Center. Twenty three American university teams competed in the 2010 Lunabotics Mining Competition. The competition was held again in May 2011 with over 60 teams registered, including international participation. The competition will be held again in May 2012 at Kennedy Space Center in Florida. . This paper contains a thorough review of the various regolith eX,cavation robotic device prototypes that competed in these NASA competitions, and will. classify the machines and their methods of excavation to document the variety of ideas that were spawned and built to compete at these events. It is hoped that documentation of these robots will serve to help future robotic excavation designers and provide a historical reference for future lunar mining machine endeavors.

301-15 East Illinois St, December 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation during the excavation process did not exceed theinstrument threshold previously stated, and ranged from a minimum of 800 cpm to a maximum of 2,800cpm shielded.

335 E. Erie, January 2016, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation during the excavation process did not exceed theinstrument threshold previously stated and ranged from a minimum of 4,900 cpm to a maximum of 10,200cpm unshielded.

215 E. Grand Ave, December 2015, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation during the excavation process did not exceed theinstrument threshold previously stated and ranged from a minimum of 6,800 cpm to a maximum of 7,200cpm unshielded.

243 E. Ontario Street - Water, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation during the excavation process did not exceed theinstrument threshold previously stated, and ranged from a minimum of 1,400 cpm to a maximum of 2,600cpm shielded.

224 E Ontario, February 2015, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation during the excavation process did not exceed theinstrument threshold previously stated and ranged from a minimum of 6,200 cpm to a maximum of 7,500cpm unshielded.

54-63 East Ohio St., Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation during the excavation process did not exceed theinstrument threshold previously stated, and ranged from a minimum of 2,000 cpm to a maximum of 2,300cpm shielded.

225 E. Grand Ave, Septmber 2015, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation during the excavation process did not exceed theinstrument threshold previously stated and ranged from a minimum of 5,300 cpm to a maximum of 9,700cpm unshielded.

78 FR 47205 - National Oil and Hazardous Substances Pollution Contingency Plan; National Priorities List...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-05

... material, isolation and capping of non- hazardous materials, installation of fencing, posting of warning... on the site, No excavations causing erosion, No excavation below base material of the road bed (State...

243 E. Ontario Street - Sewer, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation during the excavation process did not exceed theinstrument threshold previously stated, and ranged from a minimum of 1,100 cpm to a maximum of 3,600cpm shielded.

228 E. Ontario, February 2016, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation during the excavation process did not exceed theinstrument threshold previously stated and ranged from a minimum of 5,400 cpm to a maximum of 10,000cpm unshielded.

A novel energy recovery system for parallel hybrid hydraulic excavator.

PubMed

Li, Wei; Cao, Baoyu; Zhu, Zhencai; Chen, Guoan

2014-01-01

Hydraulic excavator energy saving is important to relieve source shortage and protect environment. This paper mainly discusses the energy saving for the hybrid hydraulic excavator. By analyzing the excess energy of three hydraulic cylinders in the conventional hydraulic excavator, a new boom potential energy recovery system is proposed. The mathematical models of the main components including boom cylinder, hydraulic motor, and hydraulic accumulator are built. The natural frequency of the proposed energy recovery system is calculated based on the mathematical models. Meanwhile, the simulation models of the proposed system and a conventional energy recovery system are built by AMESim software. The results show that the proposed system is more effective than the conventional energy saving system. At last, the main components of the proposed energy recovery system including accumulator and hydraulic motor are analyzed for improving the energy recovery efficiency. The measures to improve the energy recovery efficiency of the proposed system are presented.

Alternative cytoskeletal landscapes: cytoskeletal novelty and evolution in basal excavate protists

PubMed Central

Dawson, Scott C.; Paredez, Alexander R.

2016-01-01

Microbial eukaryotes encompass the majority of eukaryotic evolutionary and cytoskeletal diversity. The cytoskeletal complexity observed in multicellular organisms appears to be an expansion of components present in genomes of diverse microbial eukaryotes such as the basal lineage of flagellates, the Excavata. Excavate protists have complex and diverse cytoskeletal architectures and life cycles – essentially alternative cytoskeletal “landscapes” – yet still possess conserved microtubule- and actin-associated proteins. Comparative genomic analyses have revealed that a subset of excavates, however, lack many canonical actin-binding proteins central to actin cytoskeleton function in other eukaryotes. Overall, excavates possess numerous uncharacterized and “hypothetical” genes, and may represent an undiscovered reservoir of novel cytoskeletal genes and cytoskeletal mechanisms. The continued development of molecular genetic tools in these complex microbial eukaryotes will undoubtedly contribute to our overall understanding of cytoskeletal diversity and evolution. PMID:23312067

Performance Evaluation of Bucket based Excavating, Loading and Transport (BELT) Equipment - An OEE Approach

NASA Astrophysics Data System (ADS)

Mohammadi, Mousa; Rai, Piyush; Gupta, Suprakash

2017-03-01

Overall Equipment Effectiveness (OEE) has been used since last over two decades as a measure of performance in manufacturing industries. Unfortunately, enough, application of OEE in mining and excavation industry has not been duly adopted. In this paper an effort has been made to identify the OEE for performance evaluation of Bucket based Excavating, Loading and Transport (BELT) equipment. The conceptual model of OEE, as used in the manufacturing industries, has been revised to adapt to the BELT equipment. The revised and adapted model considered the operational time, speed and bucket capacity utilization losses as the key OEE components for evaluating the performance of BELT equipment. To illustrate the efficacy of the devised model on real-time basis, a case study was undertaken on the biggest single bucket excavating equipment - the dragline, in a large surface coal mine. One-year data was collected in order to evaluate the proposed OEE model.

The Method of Validity Evaluation of Hard Coal Excavation in Residual Seam Parts

NASA Astrophysics Data System (ADS)

Wodarski, Krzysztof; Bijańska, Jolanta; Gumiński, Adam

2017-12-01

The excavation of residual seam parts should be justified by positive assessment of the purposefulness, technical feasibility and economic effectiveness. The results of the profitability evaluation are crucial in a decision making process. The excavation of residual seam parts, even if it is possible from a technical point of view, should not be implemented if it is economically inefficient or when accompanied by a very high risk of non-recovery of invested capital resources. The article presents the evaluation method of possibilities of excavating hard coal from residual seam parts, and the example of its use in one of collieries in the Upper Silesian Coal Basin. Working in line with the developed method, allows to indicate the variant of residual seam part exploitation, which is feasible to implement from a technical point of view, and which is characterized by the highest economic effectiveness and lowest risk.

A Novel Energy Recovery System for Parallel Hybrid Hydraulic Excavator

PubMed Central

Li, Wei; Cao, Baoyu; Zhu, Zhencai; Chen, Guoan

2014-01-01

Hydraulic excavator energy saving is important to relieve source shortage and protect environment. This paper mainly discusses the energy saving for the hybrid hydraulic excavator. By analyzing the excess energy of three hydraulic cylinders in the conventional hydraulic excavator, a new boom potential energy recovery system is proposed. The mathematical models of the main components including boom cylinder, hydraulic motor, and hydraulic accumulator are built. The natural frequency of the proposed energy recovery system is calculated based on the mathematical models. Meanwhile, the simulation models of the proposed system and a conventional energy recovery system are built by AMESim software. The results show that the proposed system is more effective than the conventional energy saving system. At last, the main components of the proposed energy recovery system including accumulator and hydraulic motor are analyzed for improving the energy recovery efficiency. The measures to improve the energy recovery efficiency of the proposed system are presented. PMID:25405215

Generation of sedimentary fabrics and facies by repetitive excavation and storm infilling of burrow networks Holocene of south Florida and Caicos Platform, B. W. I

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tedesco, L.P.; Wanless, H.R.

Excavation of deep, open burrow networks and subsequent infilling with sediment from the surface produces an entirely new sedimentary deposit and results in obliteration to severe diagenetic transformation of precursor depositional facies. Repetitive excavation and infilling is responsible for creating the preserved depositional facies of many marine deposits. Excavating burrowers occur from intertidal to abyssal depths, and are important throughout the Phanerozoic. The repetitive coupling of deep, open burrow excavation with subsequent storm sediment infilling of open burrow networks is a gradual process that ultimately results in the loss of the original deposit and the generation of new lithologies, fabricsmore » and facies. The new lithologies are produced in the subsurface and possess fabrics, textures and skeletal assemblages that are not a direct reflection of either precursor facies or the surficial depositional conditions. Sedimentary facies generated by repetitive burrow excavation and infilling commonly are massively bedded and generally are mottled skeletal packstones. Skeletal grains usually are well-preserved and coarser components are concentrated in burrow networks, pockets and patches. The coarse skeletal components of burrow-generated facies are a mixture of coarse bioclasts from the precursor facies and both the coarse and fine skeletal material introduced from the sediment surface. Many so-called bioturbated or massive facies may, in fact, be primary depositional facies generated in the subsurface and represent severe diagenetic transformation of originally deposited sequences. In addition, mudstones and wackestones mottled with packstone patches may record storm sedimentation.« less

Steel Sheet Piles - Applications and Elementary Design Issues

NASA Astrophysics Data System (ADS)

Sobala, Dariusz; Rybak, Jarosław

2017-10-01

High-intensity housing having been carried out in town’s centres causes that many complex issues related to earthworks and foundations must be resolved. Project owners are required to ensure respective number of parking bays, which in turn demands 2-3 storeys of underground car parks. It is especially difficult to fulfil in dense buildings of old town areas where apart from engineering problems, very stringent requirements of heritage conservator supervision are also raised. The problems with ensuring stability of excavation sidewalls need to be, at the same time, dealt with analysis of foundations of neighbouring structures, and possible strengthening them at the stages of installing the excavation protection walls, progressing the excavations and constructing basement storeys. A separate problem refers to necessity of constructing underground storeys below the level of local groundwater. This requires long-term lowering of water table inside excavation while at possibly limited intervention in hydrological regime beyond the project in progress. In river valleys such “hoarding off” the excavation and cutting off groundwater leads to temporary or permanent disturbances of groundwater run-off and local swellings. Traditional way to protect vertical fault and simultaneously to cut-off groundwater inflow consists in application of steel sheet pilings. They enable to construct monolithic reinforced concrete structures of underground storeys thus ensuring both their tightness and high rigidity of foundation. Depending on situation, steel sheet pilings can be in retrieving or staying-in-place versions. This study deals with some selected aspects of engineering design and fabrication of sheet piling for deep excavations and underground parts of buildings.

545 N McClurg Ct, February 2015, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation during the excavation process did not exceed theinstrument threshold previously stated and ranged from a minimum of 5,700 cpm to a maximum of 13,500cpm unshielded.

13. AERIAL VIEW SHOWING IN THE FOREGROUND, EXCAVATION FOR THE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

13. AERIAL VIEW SHOWING IN THE FOREGROUND, EXCAVATION FOR THE SPILLWAY APRON.... Volume XVII, No. 12, December 26, 1939. - Prado Dam, Spillway, Santa Ana River near junction of State Highways 71 & 91, Corona, Riverside County, CA

29 CFR 570.68 - Occupations in excavation operations (Order 17).

Code of Federal Regulations, 2010 CFR

2010-07-01

... Hazardous for the Employment of Minors Between 16 and 18 Years of Age or Detrimental to Their Health or Well-Being § 570.68 Occupations in excavation operations (Order 17). (a) Finding and declaration of fact. The...

356 E Grand, July 2016, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavations and of the spoil during the excavation process didnot exceed the instrument threshold previously stated and ranged from a minimum of 5,000 cpm to amaximum of 9,600 cpm unshielded.

237 E Ontario, July 2016, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavations and of the spoil during the excavation process didnot exceed the instrument threshold previously stated and ranged from a minimum of 8,600 cpm to amaximum of 9,500 cpm unshielded.

226-228 E Ontario St, December 2014, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation during the excavation process did not exceed theunshielded instrument threshold previously stated and ranged from a minimum of 6,200 cpm to amaximum of 8,800 cpm unshielded.

76 FR 19129 - Excavations (Design of Cave-in Protection Systems); Extension of the Office of Management and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-06

... paragraphs require employers to use protective systems to prevent cave-ins during excavation work; these... work, thereby assuring employees of maximum protection against cave-ins. II. Special Issues for Comment...

441 E Ontario, August 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gammameasurements within the excavation and the spoil materials generated during the excavation process did notexceed the respective threshold values previously stated and ranged from a minimum of 5,200 cpm to amaximum of 9,200 cpm.

502 N Peshtigo, October 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation andthe spoil materials generated during the excavation process did not exceed the respective thresholdvalues previously stated and ranged from a minimum of 690 cpm to a maximum of 6,950 cpm.

380 E. North Water St, April 2016, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation during the excavation process did not exceed theinstrument threshold previously stated and ranged from a minimum of 6,800 cpm to a maximum of 12,100cpm unshielded.

Abduction of Toe-excavation Induced Failure Process from LEM and FDM for a Dip Slope with Rock Anchorage in Taiwan

NASA Astrophysics Data System (ADS)

Huang, W.-S.; Lin, M.-L.; Liu, H.-C.; Lin, H.-H.

2012-04-01

On April 25, 2010, without rainfall and earthquake triggering a massive landslide (200000 m3) covered a 200m stretch of Taiwan's National Freeway No. 3, killing 4 people, burying three cars and destroying a bridge. The failure mode appears to be a dip-slope type failure occurred on a rock anchorage cut slope. The strike of Tertiary sedimentary strata is northeast-southwest and dip 15˚ toward southeast. Based on the investigations of Taiwan Geotechnical Society, there are three possible factors contributing to the failure mechanism as follow:(1) By toe-excavation during construction in 1998, the daylight of the sliding layer had induced the strength reduction in the sliding layer. It also caused the loadings of anchors increased rapidly and approached to their ultimate capacity; (2) Although the excavated area had stabilized soon with rock anchors and backfills, the weathering and groundwater infiltration caused the strength reduction of overlying rock mass; (3) The possible corrosion and age of the ground anchors deteriorate the loading capacity of rock anchors. Considering the strength of sliding layer had reduced from peak to residual strength which was caused by the disturbance of excavation, the limit equilibrium method (LEM) analysis was utilized in the back analysis at first. The results showed the stability condition of slope approached the critical state (F.S.≈1). The efficiency reduction of rock anchors and strength reduction of overlying stratum (sandstone) had been considered in following analysis. The results showed the unstable condition (F.S. <1). This research also utilized the result of laboratory test, geological strength index(GSI) and finite difference method (FDM, FLAC 5.0) to discuss the failure process with the interaction of disturbance of toe-excavation, weathering of rock mass, groundwater infiltration and efficiency reduction of rock anchors on the stability of slope. The analysis indicated that the incremental load of anchors have similar tendency comparing to the monitoring records in toe-excavation stages. This result showed that the strength of the sliding layer was significantly influenced by toe-excavation. The numerical model which calibrated with monitoring records in excavation stage was then used to discuss the failure process after backfilling. The results showed the interaction of different factors into the failure process. Keyword: Dip slope failure, rock anchor, LEM, FDM, GSI, back analysis

355 E Riverwalk, February 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 2,600 cpm to 4,300 cpm. No count rates were found at any time that exceeded the threshold limit of 7,029 cpm.

230 E. Ontario, May 2018, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,800 cpm to 2,600 cpm.No count rates were found at any time that exceeded the threshold limit of 7,366 cpm.

PLANT AND PIER #2 EXCAVATION. View is to the northeast, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PLANT AND PIER #2 EXCAVATION. View is to the northeast, looking from Humboldt County side of river toward Trinity County side - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

Project Report: Active Pipeline Encroachment Detector (Phase I)

DOT National Transportation Integrated Search

2008-06-10

Of the many pipeline accident causes that occur to oil and gas pipelines, approximately 40% of are caused by third-party excavating activities into the buried pipeline right of way (ROW). According to DOT statistics, excavation damage is the second l...

26. EXCAVATION OF EAST (FRONT) BASEMENT WELL AND DRAINAGE SYSTEM, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

26. EXCAVATION OF EAST (FRONT) BASEMENT WELL AND DRAINAGE SYSTEM, WITH ARCHED ENTRY INTO BASEMENT UNDER FRONT ENTRY IN BACKGROUND, LOOKING NORTH (NOTE GALLETING IN BRICK FOUNDATION) - Belair, Tulip Grove Drive, Belair-at-Bowie, Bowie, Prince George's County, MD

450 N. Cityfront Plaza, October 2016, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavations and of the spoil during the excavation process didnot exceed the instrument threshold previously stated and ranged from a minimum of 4,400 cpm to amaximum of 6,000 cpm unshielded.

465 E. Illinois St., February 2015, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Field gamma measurements within the excavation and the spoil materials generatedduring the excavation process did not exceed the field instrument threshold previously stated and rangedfrom a minimum of 10,000 cpm to a maximum of 15,500 cpm unshielded.

CONSTRUCTION PROGRESS PHOTO SHOWING EXCAVATION PIT FOR MAIN PROCESSING BUILDING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

CONSTRUCTION PROGRESS PHOTO SHOWING EXCAVATION PIT FOR MAIN PROCESSING BUILDING (CPP-601) LOOKING SOUTH. INL PHOTO NUMBER NRTS-50-693. Unknown Photographer, 1950 - Idaho National Engineering Laboratory, Idaho Chemical Processing Plant, Fuel Reprocessing Complex, Scoville, Butte County, ID

465 N. Park Ave, October 2016, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavations and of the spoil during the excavation process didnot exceed the instrument threshold previously stated and ranged from a minimum of 4,100 cpm to amaximum of 16,600 cpm unshielded.

300 E Randolph, May 2011, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation andthe spoil materials generated during the excavation process did not exceed the respective threshold valuespreviously stated and ranged from a minimum of 4,900 cpm to a maximum of 9,300 cpm.

222 North Columbus Dr., August 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation andthe spoil materials generated during the excavation process did not exceed the respective thresholdvalues previously stated and ranged from a minimum of 2,200 cpm to a maximum of 3,500 cpm.

425 E Randolph, August 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation andthe spoil materials generated during the excavation process did not exceed the respective thresholdvalues previously stated and ranged from a minimum of 1,800 cpm to a maximum of 4,900 cpm.

248 E. South Water, August 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation andthe spoil materials generated during the excavation process did not exceed the respective thresholdvalues previously stated and ranged from a minimum of 1,600 cpm to a maximum of 2,900 cpm.

200 N Columbus Dr, August 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation andthe spoil materials generated during the excavation process did not exceed the respective thresholdvalues previously stated and ranged from a minimum of 2,500 cpm to a maximum of 3,300 cpm.

301 E South Water, August 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation andthe spoil materials generated during the excavation process did not exceed the respective thresholdvalues previously stated and ranged from a minimum of 2,200 cpm to a maximum of 4,500 cpm.

426 East Grand Ave, October 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation andthe spoil materials generated during the excavation process did not exceed the respective thresholdvalues previously stated and ranged from a minimum of 740 cpm to a maximum of 5,930 cpm.

165 E Ontario, October 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation and the spoil materials generatedduring the excavation process did not exceed the respective threshold values previously stated andranged from a minimum of 2, 150 cpm to a maximum of 6,270 cpm.

659-663 N Michigan, March 2011, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation and the spoilmaterials generated during the excavation process did not exceed the respective threshold valuepreviously stated and ranged from a minimum of 4,180 cpm to a maximum of 5,545 cpm.

633 N. Michigan Ave, May 2016, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavations and of the spoil during the excavation process didnot exceed the instrument threshold previously stated and ranged from a minimum of 4,400 cpm to amaximum of 5,900 cpm unshielded.

157 - 165 E. Ohio, May 2016, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavations and of the spoil during the excavation process didnot exceed the instrument threshold previously stated and ranged from a minimum of 5,000 cpm to amaximum of 5,900 cpm unshielded.

400 E Randolph, August 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation andthe spoil materials generated during the excavation process did not exceed the respective thresholdvalues previously stated and ranged from a minimum of 1,600 cpm to a maximum of 4,200 cpm.

400 E North Water, August 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation andthe spoil materials generated during the excavation process did not exceed the respective thresholdvalues previously stated and ranged from a minimum of 2,400 cpm to a maximum of 4,500 cpm.

512 N McClurg, August 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurementswithin the excavation and the spoil materials generated during the excavation process did not exceed therespective threshold values previously stated and ranged from a minimum of 6,500 cpm to a maximum of9,500 cpm.

Use of ground-penetrating radar techniques in archaeological investigations

NASA Technical Reports Server (NTRS)

Doolittle, James A.; Miller, W. Frank

1991-01-01

Ground-penetrating radar (GPR) techniques are increasingly being used to aid reconnaissance and pre-excavation surveys at many archaeological sites. As a 'remote sensing' tool, GPR provides a high resolution graphic profile of the subsurface. Radar profiles are used to detect, identify, and locate buried artifacts. Ground-penetrating radar provides a rapid, cost effective, and nondestructive method for identification and location analyses. The GPR can be used to facilitate excavation strategies, provide greater areal coverage per unit time and cost, minimize the number of unsuccessful exploratory excavations, and reduce unnecessary or unproductive expenditures of time and effort.

Digging the termite way: crowding simple robots to excavate ramification structures

NASA Astrophysics Data System (ADS)

Bardunias, Paul

The complex ramification network that termites excavate in soil in search of resources has been shown to emerge from interactions between individuals during periodic crowding at the tips of tunnels. Excavation in these social insects is carried out by a rotation of termites removing soil from the tip of an expanding tunnel and depositing it back along the tunnel walls. Bristle bots, modified to either rock or turn on contact with soil in an artificial tunnel, were used to replicate this process. As in termites, congestion at tunnel tips leads to the widening and branching of tunnels.

Support system, excavation arrangement, and process of supporting an object

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arnold, Bill W.

2017-08-01

A support system, an excavation arrangement, and a process of supporting an object are disclosed. The support system includes a weight-bearing device and a camming mechanism positioned below the weight-bearing device. A downward force on the weight-bearing device at least partially secures the camming mechanism to opposing surfaces. The excavation arrangement includes a borehole, a support system positioned within and secured to the borehole, and an object positioned on and supported by the support system. The process includes positioning and securing the support system and positioning the object on the weight-bearing device.

Selection of Excavators for Earth Work on the Basis of their Performance

NASA Astrophysics Data System (ADS)

Vondráčková, Terezie; Voštová, Věra

2017-10-01

For the specific construction of the reconstruction of the railway section Ostrov nad Oslavou and Žďár nad Sázavou will be done removed the railway superstructure and the partial adjustment of the substructure including drainage. For the earthwork will be used excavators of the company Komatsu, with the possibility of adjustment of parameters of the working tool - the length of the bracket and the volume of the shovel. The determined value will be purely indicative, as it does not affect how the operator of the excavator handles the discharge of cargo means.

Hominid visitation of the Moravian Karst during the Middle-Upper Paleolithic transition: New results from Pod Hradem Cave (Czech Republic).

PubMed

Nejman, L; Wood, R; Wright, D; Lisá, L; Nerudová, Z; Neruda, P; Přichystal, A; Svoboda, J

2017-07-01

In 1956-1958, excavations of Pod Hradem Cave in Moravia (eastern Czech Republic) revealed evidence for human activity during the Middle-Upper Paleolithic transition. This spanned 25,050-44,800 cal BP and contained artefacts attributed to the Aurignacian and Szeletian cultures, including those made from porcelanite (rarely used at Moravian Paleolithic sites). Coarse grained excavation techniques and major inversions in radiocarbon dates meant that site chronology could not be established adequately. This paper documents re-excavation of Pod Hradem in 2011-2012. A comprehensive AMS dating program using ultrafiltration and ABOx-SC pre-treatments provides new insights into human occupation at Pod Hradem Cave. Fine-grained excavation reveals sedimentary units spanning approximately 20,000 years of the Early Upper Paleolithic and late Middle Paleolithic periods, thus making it the first archaeological cave site in the Czech Republic with such a sedimentary and archaeological record. Recent excavation confirms infrequent human visitation, including during the Early Aurignacian by people who brought with them portable art objects that have no parallel in the Czech Republic. Raw material diversity of lithics suggests long-distance imports and ephemeral visits by highly mobile populations throughout the EUP period. Copyright © 2017 Elsevier Ltd. All rights reserved.

Stability Calculation Method of Slope Reinforced by Prestressed Anchor in Process of Excavation

PubMed Central

Li, Zhong; Wei, Jia; Yang, Jun

2014-01-01

This paper takes the effect of supporting structure and anchor on the slope stability of the excavation process into consideration; the stability calculation model is presented for the slope reinforced by prestressed anchor and grillage beam, and the dynamic search model of the critical slip surface also is put forward. The calculation model of the optimal stability solution of each anchor tension of the whole process is also given out, through which the real-time analysis and checking of slope stability in the process of excavation can be realized. The calculation examples indicate that the slope stability is changed with the dynamic change of the design parameters of anchor and grillage beam. So it is relatively more accurate and reasonable by using dynamic search model to determine the critical slip surface of the slope reinforced by prestressed anchor and grillage beam. Through the relationships of each anchor layout and the slope height of various stages of excavation, and the optimal stability solution of prestressed bolt tension design value in various excavation stages can be obtained. The arrangement of its prestressed anchor force reflects that the layout of the lower part of bolt and the calculation of slope reinforcement is in line with the actual. These indicate that the method is reasonable and practical. PMID:24683319

Stability calculation method of slope reinforced by prestressed anchor in process of excavation.

PubMed

Li, Zhong; Wei, Jia; Yang, Jun

2014-01-01

This paper takes the effect of supporting structure and anchor on the slope stability of the excavation process into consideration; the stability calculation model is presented for the slope reinforced by prestressed anchor and grillage beam, and the dynamic search model of the critical slip surface also is put forward. The calculation model of the optimal stability solution of each anchor tension of the whole process is also given out, through which the real-time analysis and checking of slope stability in the process of excavation can be realized. The calculation examples indicate that the slope stability is changed with the dynamic change of the design parameters of anchor and grillage beam. So it is relatively more accurate and reasonable by using dynamic search model to determine the critical slip surface of the slope reinforced by prestressed anchor and grillage beam. Through the relationships of each anchor layout and the slope height of various stages of excavation, and the optimal stability solution of prestressed bolt tension design value in various excavation stages can be obtained. The arrangement of its prestressed anchor force reflects that the layout of the lower part of bolt and the calculation of slope reinforcement is in line with the actual. These indicate that the method is reasonable and practical.

30. DETAILED FRONTAL VIEW WEST OF EXCAVATION AT SUSPECTED MICA ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

30. DETAILED FRONTAL VIEW WEST OF EXCAVATION AT SUSPECTED MICA PIT, SHOWING SOIL MIXED WITH MICA FLAKES AT REAR, AND DEEPER HOLE OF VIRGIN SOIL AT FRONT. - Vulcan Crucible Steel Company, Building No. 3, 100 First Street, Aliquippa, Beaver County, PA

A new bee species that excavates sandstone nests

USDA-ARS?s Scientific Manuscript database

Many wonder why animals act in seemingly injurious ways. Understanding the behavior of pollinators such as bees is especially important because of the necessary ecosystem service they provide. The new species Anthophora pueblo, discovered excavating sandstone nests, provides a model system for addre...

501-59 E Illinois Street, January 2018, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavations and of the spoil during the excavation process did not exceed the instruments threshold previously stated and ranged from a minimum of 1,000 cpm to amaximum of 4,000 cpm shielded.

200 E Illinois St, December 2011, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Field gamma measurements within the excavation and the spoil materials generated during the excavation process did not exceed the respective threshold value previously stated and ranged from a minimum of 7,100 cpm to amaximum of 9,400 cpm unshielded.

9. Excavation work at Pleasant Dam (now called Waddell Dam). ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. Excavation work at Pleasant Dam (now called Waddell Dam). Photographer unknown, July, 22, 1926. Source: Maricopa County Municipal Water Conservation District Number One (MWD). - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

371 E. Lower Wacker Drive, March 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,600 cpm to 2,600 cpm.No count rates were found at any time that exceeded the threshold limit of 7,029 cpm.

220 E. Illinois St., March 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,500 cpm to 5,600 cpm.No count rates were found at any time that exceeded the threshold limit of 7,029 cpm.

8-37 W. Hubbard, March 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,800 cpm to 5,200 cpm. No count rates were found at any time that exceeded the threshold limit of 7,389 cpm.

429 E. Grand Ave, March 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,700 cpm to 3,700 cpm.No count rates were found at any time that exceeded the threshold limit of 7,029 cpm.

201-211 E. Grand Ave, January 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,700 cpm to 3,900 cpm. No count rates were found at any time that exceeded the threshold limit of 7,029 cpm.

230 N. Michigan Ave, April 2018, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,400 cpm to 3,800 cpm. No count rates were found at any time that exceeded the threshold limit of 6,542 cpm.

36 W. Illinois St, March 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,800 cpm to 2,400 cpm.No count rates were found at any time that exceeded the threshold limit of 7,029 cpm.

1-37 W. Hubbard, March 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,800 cpm to 5,000 cpm. No count rates were found at any time that exceeded the threshold limit of 7,389 cpm.

211 E. Ohio St., March 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,700 cpm to 2,300 cpm.No count rates were found at any time that exceeded the threshold limit of 6,338 cpm.

140-200 E. Grand Ave, February 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,700 cpm to 2,400 cpm. No count rates were found at any time that exceeded the threshold limit of 6,738 cpm.

430 N. Michigan Ave, January 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,600 cpm to 2,100 cpm. No count rates were found at any time that exceeded the threshold limit of 6,338 cpm.

401-599 N. Dearborn St., March 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation, The count rates in the excavation ranged from 1,700 cpm to 5,800 cpm.No count rates were found at any time that exceeded the threshold limit of 6,738 cpm.

VIEW OF SOUTH GUN EMPLACEMENT. NOTE THE EXCAVATED EDGE OF ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF SOUTH GUN EMPLACEMENT. NOTE THE EXCAVATED EDGE OF THE GUN BLOCK IN THE FOREGROUND. VIEW FACING NORTH - U.S. Naval Base, Pearl Harbor, Ford Island 5-Inch Antiaircraft Battery, South Gun Emplacement, Ford Island, Pearl City, Honolulu County, HI

639-640 E. Ohio St, August 2014, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation and of the spoil materials generatedduring the excavation process did not exceed the instrument threshold previously stated and ranged froma minimum of 5,100 cpm to a maximum of 6,700 cpm unshielded.

500-03 N. Peshtigo, October 2016, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation and of the spoil during the excavation process didnot exceed the instrument threshold previously stated and predominantly ranged from a minimum of5,600 cpm to a maximum of 11,000 cpm unshielded.

CONSTRUCTION PROGRESS PHOTO SHOWING EXCAVATION PIT FOR MAIN PROCESSING BUILDING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

CONSTRUCTION PROGRESS PHOTO SHOWING EXCAVATION PIT FOR MAIN PROCESSING BUILDING (CPP-601) LOOKING NORTHWEST. INL PHOTO NUMBER NRTS-50-885. Unknown Photographer, 10/30/1950 - Idaho National Engineering Laboratory, Idaho Chemical Processing Plant, Fuel Reprocessing Complex, Scoville, Butte County, ID

301-40 N. Field, October 2016, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavations and of the spoil during the excavation process didnot exceed the instrument threshold previously stated and predominantly ranged from a minimum of3,000 cpm to a maximum of 10,000 cpm unshielded.

405 E Illinois St, May 2014, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation and the spoil materials generatedduring the excavation process did not exceed the field instrument threshold previously stated and rangedfrom a minimum of 6,000 cpm to a maximum of 8,050 cpm unshielded

200-210 E. Ohio St., May 2014, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation and the spoil materials generatedduring the excavation process did not exceed the field instrument threshold previously stated and rangedfrom a minimum of 6,000 cpm to a maximum of 7,500 cpm unshielded

201 E South Water, December 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation and the spoil materials generated during the excavation process did not exceed the respective threshold values previously stated and ranged from a minimum of7,234 cpm to a maximum of 9,872 cpm.

543 N McClurg, October 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation andthe spoil materials generated during the excavation process did not exceed the respective thresholdvalues previously stated and ranged from a minim um of 1,020 cpm to a maxim um of 7,150 cpm.

237 E. Ontario St., January 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The measurements within the excavations and of the soil did not exceed the instrument USEPA threshold and ranged from a minimum of 4,800 cpm to a maximum of 8,300 cpm unshielded.

Modeling of damage, permeability changes and pressure responses during excavation of the TSX tunnel in granitic rock at URL, Canada

NASA Astrophysics Data System (ADS)

Rutqvist, Jonny; Börgesson, Lennart; Chijimatsu, Masakazu; Hernelind, Jan; Jing, Lanru; Kobayashi, Akira; Nguyen, Son

2009-05-01

This paper presents numerical modeling of excavation-induced damage, permeability changes, and fluid-pressure responses during excavation of a test tunnel associated with the tunnel sealing experiment (TSX) at the Underground Research Laboratory (URL) in Canada. Four different numerical models were applied using a wide range of approaches to model damage and permeability changes in the excavation disturbed zone (EDZ) around the tunnel. Using in situ calibration of model parameters, the modeling could reproduce observed spatial distribution of damage and permeability changes around the tunnel as a combination of disturbance induced by stress redistribution around the tunnel and by the drill-and-blast operation. The modeling showed that stress-induced permeability increase above the tunnel is a result of micro and macrofracturing under high deviatoric (shear) stress, whereas permeability increase alongside the tunnel is a result of opening of existing microfractures under decreased mean stress. The remaining observed fracturing and permeability changes around the periphery of the tunnel were attributed to damage from the drill-and-blast operation. Moreover, a reasonably good agreement was achieved between simulated and observed excavation-induced pressure responses around the TSX tunnel for 1 year following its excavation. The simulations showed that these pressure responses are caused by poroelastic effects as a result of increasing or decreasing mean stress, with corresponding contraction or expansion of the pore volume. The simulation results for pressure evolution were consistent with previous studies, indicating that the observed pressure responses could be captured in a Biot model using a relatively low Biot-Willis’ coefficient, α ≈ 0.2, a porosity of n ≈ 0.007, and a relatively low permeability of k ≈ 2 × 10-22 m2, which is consistent with the very tight, unfractured granite at the site.

Association of Hospital Construction with the Development of Healthcare Associated Environmental Mold Infections (HAEMI) in Pediatric Patients with Leukemia

PubMed Central

Pokala, Hanumantha R.; Leonard, David; Cox, Jennifer; Metcalf, Pat; McClay, John; Siegel, Jane; Winick, Naomi

2014-01-01

Background Healthcare associated mold infections (HAEMI) increase morbidity and mortality in children with leukemia. Excavation adjacent to Children’s Medical Center Dallas (CMCD) April 2006–February 2007 provided an opportunity to determine if excavation adjacent to a hospital building is associated with increased risk of developing HAEMI in children receiving intensive chemotherapy for acute leukemia. Methods Children who began receiving intensive chemotherapy for acute leukemia at CMCD from 2004–2008 were identified (N=275). Exposures to the CMCD campus during intensive chemotherapy and duration of neutropenia per exposure were recorded. Proven, probable or possible invasive fungal disease (IFD) was classified using EORTC/MSG guidelines. Institutional guidelines categorized mold infections as definite or possible HAEMI. A bivariate time-to-event model compared the association of excavation with HAEMI and yeast infections, controlling for neutropenia. Results There were 7454 CMCD exposures, 1007(13.5%) during excavation. Of 50 cases of IFD, 31 were HAEMI. By time-to-event analysis exposure to the CMCD campus during the excavation period was significantly associated with HAEMI (HR=2.8, P=0.01) but not yeast infections (HR=0.75, P=0.75). Neutropenia was significantly associated with both HAEMI and yeast infections (P<0.001). Voriconazole prophylaxis did not prevent HAEMI in 42% of the 14 patients with AML who had been receiving this agent. Conclusion This study is the first to demonstrate an association between exposure to hospital construction that includes excavation and HAEMI in pediatric oncology patients. Since neutropenic patients need protection from aerosolized fungal spores during visits to expanding medical centers, preventive strategies with adherence monitoring need additional study. PMID:23970381

Endoscopic excavation for gastric heterotopic pancreas: an analysis of 42 cases from a tertiary center.

PubMed

Zhang, Yu; Huang, Qin; Zhu, Lin-hong; Zhou, Xian-bin; Ye, Li-ping; Mao, Xin-li

2014-09-01

Because of the difficulty associated with making an accurate diagnosis of gastric heterotopic pancreas (HP) before surgery, surgical resection is usually performed in suspected cases. However, this is an invasive procedure and prone to certain surgical complications. This study was designed to evaluate the feasibility of endoscopic excavation for gastric HP, as well as the value of endoscopic ultrasonography (EUS) in diagnosing gastric HP. Between January 2007 and January 2013, 42 consecutive patients with gastric HP were enrolled in this retrospective study. Key steps: (1) Injection of a solution (100 ml saline + 2 ml indigo carmine + 1 ml epinephrine) into the submucosal layer after making several dots around the lesion; (2) Incision of the mucosa outside the marker dots with a needle-knife, and then circumferential excavation until complete resection of the lesion; (3) Closure of the artificial ulcer with several clips after tumor removal. In this study, 18 cases (42.9%) were suspected as gastric HP (assessed by two experienced endoscopists before endoscopic excavation), 8 (19.0%) were suspected as gastrointestinal stromal tumors, 7 (16.7%) as gastric polyp, and the remaining 9 cases (21.4%) were still unknown. The mean procedure duration was 28.6 min. En bloc resection by endoscopic excavation was achieved in 40 cases (95.2%), and no massive bleeding, delayed bleeding, perforation, or other severe complication occurred in these patients. Among the 42 lesions, a tube echo could be detected in 11 cases by EUS. Those 11 cases were diagnosed as gastric HP by histopathology. Endoscopic excavation appears to be a safe and feasible procedure for accurate histopathologic evaluation and curative treatment in gastric HP. Use of EUS has some value in the diagnosis of gastric HP before the procedure

In Situ Observation of Failure Mechanisms Controlled by Rock Masses with Weak Interlayer Zones in Large Underground Cavern Excavations Under High Geostress

NASA Astrophysics Data System (ADS)

Duan, Shu-Qian; Feng, Xia-Ting; Jiang, Quan; Liu, Guo-Feng; Pei, Shu-Feng; Fan, Yi-Lin

2017-09-01

A weak interlayer zone (WIZ) is a poor rock mass system with loose structure, weak mechanical properties, variable thickness, random distribution, strong extension, and high risk due to the shear motion of rock masses under the action of tectonism, bringing many stability problems and geological hazards, especially representing a potential threat to the overall stability of rock masses with WIZs in large underground cavern excavations. Focusing on the deformation and failure problems encountered in the process of excavation unloading, this research proposes comprehensive in situ observation schemes for rock masses with WIZs in large underground cavern on the basis of the collection of geological, construction, monitoring, and testing data. The schemes have been fully applied in two valuable project cases of an underground cavern group under construction in the southwest of China, including the plastic squeezing-out tensile failure and the structural stress-induced collapse of rock masses with WIZs. In this way, the development of rock mass failure, affected by the step-by-step excavations along the cavern's axis and the subsequent excavation downward, could be observed thoroughly. Furthermore, this paper reveals the preliminary analyses of failure mechanism of rock masses with WIZs from several aspects, including rock mass structure, strength, high stress, ground water effects, and microfracture mechanisms. Finally, the failure particularities of rock masses with WIZs and rethink on prevention and control of failures are discussed. The research results could provide important guiding reference value for stability analysis, as well as for rethinking the excavation and support optimization of rock masses with WIZs in similar large underground cavern under high geostress.

Integration Of 3D Geographic Information System (GIS) For Effective Waste Management Practice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rood, G.J.; Hecox, G.R.

2006-07-01

Soil remediation in response to the presence of residual radioactivity resulting from past MED/AEC activities is currently in progress under the Formerly Utilized Sites Remedial Action Program near the St. Louis, MO airport. During GY05, approximately 92,000 cubic meters (120,000 cubic yards) of radioactive soil was excavated, packaged and transported via rail for disposal at U.S. Ecology or Envirocare of Utah, LLC. To facilitate the management of excavation/transportation/disposal activities, a 3D GIS was developed for the site that was used to estimate the in-situ radionuclide activities, activities in excavation block areas, and shipping activities using a sum-of ratio (SOR) methodmore » for combining various radionuclide compounds into applicable transportation and disposal SOR values. The 3D GIS was developed starting with the SOR values for the approximately 900 samples from 90 borings. These values were processed into a three-dimensional (3D) point grid using kriging with nominal grid spacing of 1.5 by 1.5 meter horizontal by 0.3 meter vertical. The final grid, clipped to the area and soil interval above the planned base of excavation, consisted of 210,000 individual points. Standard GIS volumetric and spatial join procedures were used to calculate the volume of soil represented by each grid point, the base of excavation, depth below ground surface, elevation, surface elevation and SOR values for each point in the final grid. To create the maps needed for management, the point grid results were spatially joined to each excavation area in 0.9 meter (3 foot) depth intervals and the average SOR and total volumes were calculations. The final maps were color-coded for easy identification of areas above the specific transportation or disposal criteria. (authors)« less

401 N. Lakeshore Dr - DuSable Bike Trail, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Field gamma measurements within the remaining excavation areas, and for the spoil removed duringthe excavation process, did not exceed the instrument thresholds previously stated and ranged from aminimum of 1,300 cpm to a maximum of 4,400 cpm shielded.

17. Photocopy of photograph showing excavation of South Bank Substation ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

17. Photocopy of photograph showing excavation of South Bank Substation site, 15 May 1939 (from the BPA Photo Archives, Portland, Oregon, Negative No. 345), LOOKING WEST - Bonneville Power Administration South Bank Substation, I-84, South of Bonneville Dam Powerhouse, Bonneville, Multnomah County, OR

Muck Utilization Planning - Urban Transportation Tunneling : A Handbook of Rational Practices for Planners and Designers

DOT National Transportation Integrated Search

1977-05-01

This handbook alerts transportation system planners and designers to planning methods which can lead to more efficient use of earth and rock materials produced during excavation for transportation tunnels and large excavations. The earth and rock mat...

406 E Grand, October 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation and the spoil materials generated during the excavation process did not exceed the respective threshold values previously stated and ranged from a minim um of 1, 120 cpm to a maxim um of 6,640 cpm.

Multiple addresses: 500-59 E. Illinois St. and 500-91 E. Grand Ave., Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation during the excavation process did not exceed theinstrument threshold previously stated, and ranged from a minimum of 1,200 cpm to a maximum of 3,100cpm shielded.

Installation restoration program. Closure assessment report for UST removals at sites 4 and 5 - petroleum, oils, and lubricants facility. Virginia Air National Guard, 192nd Fighter Group, Richmond International Airport, Sandston, Virginia. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

The objectives of the closure assessment were to determine the extent of contaminated soil adjacent to the USTs requiring excavation, to provide documentation of soil and groundwater conditions following excavation, and to document closure activities in accordance with applicable VADEQ regulations. During closure activities, ASI provided technical support to the Base to ensure that the UST removal contractor (E K, Inc.) hereinafter referred to as the Contractor was in compliance with the technical requirements (as specified in the Plans and Specifications for Removal of Abandoned Underground Storage Tanks, Virginia Air National Guard, Richmond International Airport, Sandston, VA., dated July 1991more » and revised April 1992, and Addendum Numbers 1 through 7) of the contract. ASI was also responsible for collecting soil and/or groundwater closure samples from the excavations, and providing off-site fixed based laboratory analysis to verify clean conditions within the excavations.« less

Remediation of subsurface and groundwater contamination with uranium from fuel fabrication facilities at Hanau (Germany)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nitzsche, Olaf; Thierfeldt, Stefan; Hummel, Lothar

2013-07-01

This paper presents aspects of site decommissioning and clearance of a former fuel fabrication facility (development and production of fuel assemblies for research reactors and HTR) at Hanau (Germany). The main pathways for environmental contamination were deposition on soil surface and topsoil and pollution of deep soil and the aquifer by waste water channel leakage. Soil excavation could be done by classical excavator techniques. An effective removal of material from the saturated zone was possible by using advanced drilling techniques. A large amount of demolished building structure and excavated soil had to be classified. Therefore the use of conveyor detectormore » was necessary. Nearly 100000 Mg of material (excavated soil and demolished building material) were disposed of at an underground mine. A remaining volume of 700 m{sup 3} was classified as radioactive waste. Site clearance started in 2006. Groundwater remediation and monitoring is still ongoing, but has already provided excellent results by reducing the remaining Uranium considerably. (authors)« less

Analysis of 19th century ceramic fragments excavated from Pirenópolis (Goiás, Brazil) using FT-IR, Raman, XRF and SEM

NASA Astrophysics Data System (ADS)

Freitas, Renato P.; Coelho, Filipe A.; Felix, Valter S.; Pereira, Marcelo O.; de Souza, Marcos André Torres; Anjos, Marcelino J.

2018-03-01

This study used Raman, FT-IR and XRF spectroscopy and SEM to analyze ceramic fragments dating from the 19th century, excavated from an old farm in the municipality of Pirenópolis, Goiás, Brazil. The results show that the samples were produced in an open oven at a firing temperature below 500 °C, using raw materials including kaolinite, hematite, magnetite, quartz, microcline, albite, anhydrite, calcite, illite, orthoclase and MnO2. Although the analyses showed similarities in the manufacturing process and the presence of many minerals was common in all samples, multivariate statistical methods (PCA) allowed a more detailed assessment of similarities and differences in the mineral composition of the samples. The results of the PCA showed that the samples excavated in one of the slave quarters (senzalas) group with those excavated at the farmhouse, where the landowner lived, which indicates a paternalistic attitude towards captives, including the sharing of ceramic materials of everyday use.

Historical Photogrammetry: Bird's Paluxy River Dinosaur Chase Sequence Digitally Reconstructed as It Was prior to Excavation 70 Years Ago

PubMed Central

Falkingham, Peter L.; Bates, Karl T.; Farlow, James O.

2014-01-01

It is inevitable that some important specimens will become lost or damaged over time, conservation is therefore of vital importance. The Paluxy River dinosaur tracksite is among the most famous in the world. In 1940, Roland T. Bird described and excavated a portion of the site containing associated theropod and sauropod trackways. This excavated trackway was split up and housed in different institutions, and during the process a portion was lost or destroyed. We applied photogrammetric techniques to photographs taken by Bird over 70 years ago, before the trackway was removed, to digitally reconstruct the site as it was prior to excavation. The 3D digital model offers the opportunity to corroborate maps drawn by R.T. Bird when the tracksite was first described. More broadly, this work demonstrates the exciting potential for digitally recreating palaeontological, geological, or archaeological specimens that have been lost to science, but for which photographic documentation exists. PMID:24695537

Historical photogrammetry: Bird's Paluxy River dinosaur chase sequence digitally reconstructed as it was prior to excavation 70 years ago.

PubMed

Falkingham, Peter L; Bates, Karl T; Farlow, James O

2014-01-01

It is inevitable that some important specimens will become lost or damaged over time, conservation is therefore of vital importance. The Paluxy River dinosaur tracksite is among the most famous in the world. In 1940, Roland T. Bird described and excavated a portion of the site containing associated theropod and sauropod trackways. This excavated trackway was split up and housed in different institutions, and during the process a portion was lost or destroyed. We applied photogrammetric techniques to photographs taken by Bird over 70 years ago, before the trackway was removed, to digitally reconstruct the site as it was prior to excavation. The 3D digital model offers the opportunity to corroborate maps drawn by R.T. Bird when the tracksite was first described. More broadly, this work demonstrates the exciting potential for digitally recreating palaeontological, geological, or archaeological specimens that have been lost to science, but for which photographic documentation exists.

Influence of Short Distance Super-large Diameter Shield Tunneling on Existing Tunnels in Sea Areas

NASA Astrophysics Data System (ADS)

Li, Zhuolin; Liu, Dagang; Wang, Mingnian; Xiao, Shihui; Yuan, Jiawei

2018-03-01

In oder to find out the influence of large diameter shield tunneling on the existing tunnel under the condition of compound strata in the sea area, taking the Maliuzhou traffic tunnel as the research background, numerical simulation and field test were combined to get the regulation of the additional internal force and deformation of the existing tunnel caused by the shield tunneling. Analysis of the data showed that: the shield construction caused the secondary additional internal force; The moment of the vault was most affected by the tunnel excavation; The axial force of the arch bottom was most affected by the excavation of the tunnel. The deformation of arch waist near excavation tunnel was more affected by tunnel excavation than that of the other side. Combined with the construction experience, the influence of the tunnel close-distance construction on the existing tunnel was within the control range, which could ensure the normal construction.

Comparison of ISRU Excavation System Model Blade Force Methodology and Experimental Results

NASA Technical Reports Server (NTRS)

Gallo, Christopher A.; Wilkinson, R. Allen; Mueller, Robert P.; Schuler, Jason M.; Nick, Andrew J.

2010-01-01

An Excavation System Model has been written to simulate the collection and transportation of regolith on the Moon. The calculations in this model include an estimation of the forces on the digging tool as a result of excavation into the regolith. Verification testing has been performed and the forces recorded from this testing were compared to the calculated theoretical data. A prototype lunar vehicle built at the NASA Johnson Space Center (JSC) was tested with a bulldozer type blade developed at the NASA Kennedy Space Center (KSC) attached to the front. This is the initial correlation of actual field test data to the blade forces calculated by the Excavation System Model and the test data followed similar trends with the predicted values. This testing occurred in soils developed at the NASA Glenn Research Center (GRC) which are a mixture of different types of sands and whose soil properties have been well characterized. Three separate analytical models are compared to the test data.

A Comparison Between The NORCAT Rover Test Results and the ISRU Excavation System Model Predictions Results

NASA Technical Reports Server (NTRS)

Gallo, Christopher A.; Agui, Juan H.; Creager, Colin M.; Oravec, Heather A.

2012-01-01

An Excavation System Model has been written to simulate the collection and transportation of regolith on the moon. The calculations in this model include an estimation of the forces on the digging tool as a result of excavation into the regolith. Verification testing has been performed and the forces recorded from this testing were compared to the calculated theoretical data. The Northern Centre for Advanced Technology Inc. rovers were tested at the NASA Glenn Research Center Simulated Lunar Operations facility. This testing was in support of the In-Situ Resource Utilization program Innovative Partnership Program. Testing occurred in soils developed at the Glenn Research Center which are a mixture of different types of sands and whose soil properties have been well characterized. This testing is part of an ongoing correlation of actual field test data to the blade forces calculated by the Excavation System Model. The results from this series of tests compared reasonably with the predicted values from the code.

3. "TEST STAND NO. 13, EXCAVATION PLAN & SECTIONS." Specifications ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. "TEST STAND NO. 1-3, EXCAVATION PLAN & SECTIONS." Specifications No. ENG 04-353-50-10; Drawing No. 60-0906; no sheet number within title block; D.O. SERIES 1109/10. Stamped: AS BUILT. No revisions or revision dates. Last work date on this drawing "Checked by EAG, 1/31/49." Though this drawing is specific to Test Stand 1-3, it also illustrates the general methods used for excavation design and retaining wall construction at Test Stand 1-5. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-3, Test Area 1-115, northwest end of Saturn Boulevard, Boron, Kern County, CA

Percussive Excavation of Lunar Soil

NASA Technical Reports Server (NTRS)

Whittaker, Matthew P.

2008-01-01

It has been suggested using a percussive motion could improve the efficiency of excavation by up to 90%. If this is proven to be true it would be very beneficial to excavation projects on the Moon and Mars. The purpose of this study is to design, build and test a percussive tool which could dig a trench and then compare this data against that of a non-percussive tool of the same shape and size. The results of this test thus far have been inconclusive due to malfunctions in the testbed and percussive bucket; however, experimental results from small scale experiments confirm this higher efficiency and support further testing.

2011 NASA Lunabotics Mining Competition for Universities: Results and Lessons Learned

NASA Technical Reports Server (NTRS)

Mueller, Robert P.; Murphy, Gloria A.

2011-01-01

Overview: Design, build & compete remote controlled robot (Lunabot). Excavate Black Point 1 (BP-1) Lunar Simulant. Deposit minimum of 10 kg of BP-1 within 15 minutes $5000, $2500, $1000 Scholarships for most BP-1 excavated. May 23-28, 2011. Kennedy Space Center, FL. International Teams Allowed for the First Time. What is a Lunabot? a) Robot Controlled Remotely or Autonomously. b) Visual and Auditory Isolation from Operator. c) Excavates Black Point 1 (BP-l) Simulant. d) Weight Limit - 80 kg. e)Dimension Limits -1.5m width x .75m length x 2m height. f) Designed, Built and Tested by University Student Teams.

0 - 36 W. Illinois St., January 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,600 cpm to 3,700 cpm.No count rates were found at any time that exceeded the threshold limits of 6,738 cpm and 7,029 cpm.

400-449 N. State St, March 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,600 cpm to 4,300 cpm. No count rates were found at any time that exceeded the threshold limits of 6,338 cpm and 7,038 cpm.

77 FR 19799 - Pipeline Safety: Pipeline Damage Prevention Programs

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-02

...,602 to $3,445,975. Evaluating just the lower range of benefits over ten years results in a total... consequences resulting from excavation damage to pipelines. A comprehensive damage prevention program requires..., including that resulting from excavation, digging, and other impacts, is also precipitated by operators...

APPLICATION ANALYSIS REPORT - DEMONSTRATION OF A TRIAL EXCAVATION AT THE MCCOLL SUPERFUND SITE

EPA Science Inventory

In June 1990, the U.S. Environmental Protection Agency’s Region IX Superfund Program, in cooperation with EPA’s Air and Energy Engineering Research Laboratory (AEERL), and EPA’s Superfund Innovative Technology Evaluation (SITE) Program performed a trial excavation of approximatel...

150-211 E. Illinois St and 450-51 N St. Clair Streets, February 2018, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation during the excavation process did not exceed the instrument threshold previously stated and ranged from a minimum of 1,100 cpm to a maximum of 2,100cpm shielded.

9. VIEW NORTH, EXCAVATED LOCK FROM WATER STREET (Numbers painted ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. VIEW NORTH, EXCAVATED LOCK FROM WATER STREET (Numbers painted on stones for reconstruction purposes) - Bald Eagle Cross-Cut Canal Lock, North of Water Street along West Branch of Susquehanna River South bank, 500 feet East of Jay Street Bridge, Lock Haven, Clinton County, PA

MX Siting Investigation. Geotechnical Siting Status Report. Volume 2.

DTIC Science & Technology

1978-06-21

greater tnan a nominal 50 feet deep. Rock is considered any earth material which is not readily rippable by conventional excavation techniques. b. Surface...material which is not readily rippable by conventional excavation techniques. _ b. Surface water absent and occurrences of ground water greater than a

Inexpensive Device for Demonstrating Rock Slope Failure and Other Collapse Phenomena.

ERIC Educational Resources Information Center

Stimpson, B.

1980-01-01

Describes an inexpensive modeling technique for demonstrating large-scale displacement phenomena in rock masses, such as slope collapse and failure of underground openings. Excavation of the model material occurs through openings made in the polyurethane foam in the correct excavation sequence. (Author/SA)

Characteristics of H2S emission from aged refuse after excavation exposure.

PubMed

Shen, Dong-Sheng; Du, Yao; Fang, Yuan; Hu, Li-Fang; Fang, Cheng-Ran; Long, Yu-Yang

2015-05-01

Hydrogen sulfide (H2S(g)) emission from landfills is a widespread problem, especially when aged refuse is excavated. H2S(g) emission from aged refuse exposed to air was investigated and the results showed that large amounts of H2S(g) can be released, especially in the first few hours after excavation, when H2S(g) concentrations in air near refuse could reach 2.00 mg m(-3). Initial exposure to air did not inhibit the emission of H2S(g), as is generally assumed, but actually promoted it. The amounts of H2S(g) emitted in the first 2 d after excavation can be very dangerous, and the risks associated with the emission of H2S(g) could decrease significantly with time. Unlike a large number of sulfide existed under anaerobic conditions, the sulfide in aged municipal solid waste can be oxidized chemically to elemental sulfur (but not sulfate) under aerobic conditions, and its conversion rate was higher than 80%. Only microorganisms can oxidize the reduced sulfur species to sulfate, and the conversion rate could reach about 50%. Using appropriate techniques to enhance these chemical and biological transformations could allow the potential health risks caused by H2S(g) after refuse excavation to be largely avoided. Copyright © 2015 Elsevier Ltd. All rights reserved.

Lightweight Bulldozer Attachment for Construction and Excavation on the Lunar Surface

NASA Technical Reports Server (NTRS)

Mueller, Robert; Wilkinson, R. Allen; Gallo, Christopher A.; Nick, Andrew J.; Schuler, Jason M.; King, Robert H.

2009-01-01

A lightweight bulldozer blade prototype has been designed and built to be used as an excavation implement in conjunction with the NASA Chariot lunar mobility platform prototype. The combined system was then used in a variety of field tests in order to characterize structural loads, excavation performance and learn about the operational behavior of lunar excavation in geotechnical lunar simulants. The purpose of this effort was to evaluate the feasibility of lunar excavation for site preparation at a planned NASA lunar outpost. Once the feasibility has been determined then the technology will become available as a candidate element in the NASA Lunar Surface Systems Architecture. In addition to NASA experimental testing of the LANCE blade, NASA engineers completed analytical work on the expected draft forces using classical soil mechanics methods. The Colorado School of Mines (CSM) team utilized finite element analysis (FEA) to study the interaction between the cutting edge of the LANCE blade and the surface of soil. FEA was also used to examine various load cases and their effect on the lightweight structure of the LANCE blade. Overall it has been determined that a lunar bulldozer blade is a viable technology for lunar outpost site preparation, but further work is required to characterize the behavior in 1/6th G and actual lunar regolith in a vacuum lunar environment.

Reconstruction of measurable three-dimensional point cloud model based on large-scene archaeological excavation sites

NASA Astrophysics Data System (ADS)

Zhang, Chun-Sen; Zhang, Meng-Meng; Zhang, Wei-Xing

2017-01-01

This paper outlines a low-cost, user-friendly photogrammetric technique with nonmetric cameras to obtain excavation site digital sequence images, based on photogrammetry and computer vision. Digital camera calibration, automatic aerial triangulation, image feature extraction, image sequence matching, and dense digital differential rectification are used, combined with a certain number of global control points of the excavation site, to reconstruct the high precision of measured three-dimensional (3-D) models. Using the acrobatic figurines in the Qin Shi Huang mausoleum excavation as an example, our method solves the problems of little base-to-height ratio, high inclination, unstable altitudes, and significant ground elevation changes affecting image matching. Compared to 3-D laser scanning, the 3-D color point cloud obtained by this method can maintain the same visual result and has advantages of low project cost, simple data processing, and high accuracy. Structure-from-motion (SfM) is often used to reconstruct 3-D models of large scenes and has lower accuracy if it is a reconstructed 3-D model of a small scene at close range. Results indicate that this method quickly achieves 3-D reconstruction of large archaeological sites and produces heritage site distribution of orthophotos providing a scientific basis for accurate location of cultural relics, archaeological excavations, investigation, and site protection planning. This proposed method has a comprehensive application value.

Geomys bursars burrowing patterns: influence of season and food patch structure

USGS Publications Warehouse

Andersen, Douglas C.

1987-01-01

The relationship between belowground food resources and the pattern and pace of soil excavation by Geomys bursarius, the plains pocket gopher, was assessed during spring and autumn using replicated 18 x 18 m enclosures containing uniform arrays of food plants (Daucus carota) at spacings assumed to result in burrowing being energetically profitable (25 and 50 cm) or unprofitable (100 cm and empty). Soil excavation rate, measured in terms of either daily additions to tunnel length or volume, or the maximum volume excavated during a 3-d interval, varied greatly among individuals. No significant effect due to season or density of belowground plant biomass was detected when burrowing was profitable. Individuals readily initiated aboveground travel in unprofitable treatments. Soil bulk density was negatively related and animal body mass positively related to excavation rate. Individuals deposited from 41 to 87% of excavated soil on the ground surface; the remainder was used to backfill previously created tunnels or chambers. Plant size, but not plant spacing, affected the ratio of the volumes deposited aboveground and belowground. There was no evidence that animals in enclosures disturbed soil in a manner quantitatively or qualitatively different from free-ranging adults. The large proportions and absolute quantities (up to 30 L/d) of soil involved suggest that backfilling may affect ecosystem structure and functioning as much as surface mound-building.

Geophysical surveys and archaeological insights at Fort Pierre Chouteau, a frontier trading post on the Middle Missouri

NASA Astrophysics Data System (ADS)

Patton, Margaret Maurine

Fort Pierre Chouteau in present day South Dakota was the most important fur trading post of the American Fur Company in the 1830s, serving as a regional hub for the fur trade. The Fort was sold to the U.S. Military in 1855 for use as a base in the Sioux Wars but was abandoned in 1856. Geophysical surveys and previous excavations indicate evidence of both occupations. Geophysics is an important tool for determining the extent of archaeological sites, yet the relationships between geophysical anomalies and excavation features may not be readily evident. Initial geophysical surveys (Kvamme 2007) were completed to determine the extent of the fur trading Fort, and additional surveys in August 2012 used magnetometry and electrical resistance to determine if evidence of military structures exists outside of the Fort. This study examines connections between excavation features and geophysical anomalies in order to better interpret anomalies inside the Fort palisade. The palisade builder's trench, adobe pavement, post holes, and unknown structures are characterized through the analysis of the excavations and anomalies. The location of one of the military structures outside of the palisade is also identified. As many sites have histories of excavations prior to any geophysical surveys, combining the two sets of information is important in order to more fully understand site layout and the archaeological causes of geophysical anomalies.

1-99 W. Hubbard St, May 2018, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation.The count rates in the excavation ranged from 2,100 cpm to 4,200 cpm.No count rates were found at any time that exceeded the instrument specific threshold limits of 7,366 and 6,415 cpm.

STARTING EXCAVATION PIER 2. This view is roughly northeast, with ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

STARTING EXCAVATION PIER 2. This view is roughly northeast, with Pier 2 on the Trinity County end of the bridge. The old suspension bridge, at upper right, was upstream of new bridge - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

OEM unveil new ideas for shovels and excavators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fiscor, S.

2006-08-15

From upgrades to new loading arrangements, vendors are looking at new ways to optimize the production process. The paper describes P & M equipment's new C series electric shovels equipped with the centurion system, Hitachi's super-sized excavator to Canadian oil sands, and Bucyrus and Siemens' engineer shovels. 3 figs., 1 photo.

360° Video: World's First 3D Printed Excavator

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

Oak Ridge National Laboratory produced the world's first 3D printed excavator. It debuted in March 2017 at the CONEXPO-Con/AGG in Las Vegas and does more than just move dirt. It demonstrates the latest advancements in additive manufacturing - including the ability to print with metal alloys.

Challenges in Bulk Soil Sampling and Analysis for Vapor Intrusion Screening of Soil

EPA Science Inventory

This draft Engineering Issue Paper discusses technical issues with monitoring soil excavations for VOCs and describes options for such monitoring as part of a VI pathway assessment at sites where soil excavation is being considered or used as part of the remedy for VOC-contaminat...

Are pileated woodpeckers attracted to red-cockaded woodpecker cavity trees?

Treesearch

Daniel Saenz; Richard N. Conner; James R. McCormick

2002-01-01

Pileated Woodpeckers (Dryocopus pileatus) cause damage to Red-cockaded Woodpecker (Picoides borealis) cavity trees in the form of cavity enlargement or other excavations on the surface of the pine tree. However, it is not known whether Pileated Woodpeckers excavate more frequently on Red-cockaded Woodpecker cavity trees than on...

Modelling and Analysis of the Excavation Phase by the Theory of Blocks Method of Tunnel 4 Kherrata Gorge, Algeria

NASA Astrophysics Data System (ADS)

Boukarm, Riadh; Houam, Abdelkader; Fredj, Mohammed; Boucif, Rima

2017-12-01

The aim of our work is to check the stability during excavation tunnel work in the rock mass of Kherrata, connecting the cities of Bejaia to Setif. The characterization methods through the Q system (method of Barton), RMR (Bieniawski classification) allowed us to conclude that the quality of rock mass is average in limestone, and poor in fractured limestone. Then modelling of excavation phase using the theory of blocks method (Software UNWEDGE) with the parameters from the recommendations of classification allowed us to check stability and to finally conclude that the use of geomechanical classification and the theory of blocks can be considered reliable in preliminary design.

Remote Excavation System technology evaluation report: Buried Waste Robotics Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1993-09-01

This document describes the results from the Remote Excavation System demonstration and testing conducted at the Idaho National Engineering Laboratory during June and July 1993. The purpose of the demonstration was to ascertain the feasibility of the system for skimming soil and removing various types of buried waste in a safe manner and within all regulatory requirements, and to compare the performances of manual and remote operation of a backhoe. The procedures and goals of the demonstration were previously defined in The Remote Excavation System Test Plan, which served as a guideline for evaluating the various components of the systemmore » and discussed the procedures used to conduct the tests.« less

Regolith Advanced Surface Systems Operations Robot (RASSOR) Phase 2 and Smart Autonomous Sand-Swimming Excavator

NASA Technical Reports Server (NTRS)

Sandy, Michael

2015-01-01

The Regolith Advanced Surface Systems Operations Robot (RASSOR) Phase 2 is an excavation robot for mining regolith on a planet like Mars. The robot is programmed using the Robotic Operating System (ROS) and it also uses a physical simulation program called Gazebo. This internship focused on various functions of the program in order to make it a more professional and efficient robot. During the internship another project called the Smart Autonomous Sand-Swimming Excavator was worked on. This is a robot that is designed to dig through sand and extract sample material. The intern worked on programming the Sand-Swimming robot, and designing the electrical system to power and control the robot.

CUTS FOR MTR EXCAVATION ILLUSTRATE SEDIMENTARY MANTLE OF SOIL AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

CUTS FOR MTR EXCAVATION ILLUSTRATE SEDIMENTARY MANTLE OF SOIL AND GRAVEL OVERLAYING LAVA ROCK FIFTY FEET BELOW. SAGEBRUSH HAS BEEN SCOURED FROM REST OF SITE. CAMERA PROBABLY FACES SOUTHWEST. INL NEGATIVE NO. 67. Unknown Photographer, 6/4/1950 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

VIEW OF PARTIALLY EXCAVATED MILL RUINS LOOKING NORTHWEST SHOWING UNIDENTIFIED ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF PARTIALLY EXCAVATED MILL RUINS LOOKING NORTHWEST SHOWING UNIDENTIFIED PIT IN RIGHT FOREGROUND, MASONRY BASE FOR STEAM ENGINE AND CANE MILL IN LEFT CENTER, PURGING HOUSE AND CHIMNEY IN BACKGROUND - Hacienda Azucarera La Esperanza, Mill (Ruins), 2.65 miles North of PR Route 2 Bridge Over Manati River, Manati, Manati Municipio, PR

Resisting English: Excavating English Ideologies of Young Boys through Chutkule at an Indian Orphanage

ERIC Educational Resources Information Center

Bhattacharya, Usree

2017-01-01

The prevailing scholarship on Indians' beliefs about English has, with few exceptions, largely failed to capture ideological resistance. Given the supremacy of English within the hierarchically ordered and unequal linguistic landscape in India, this study intervenes within this limited area of research. This investigation excavates ideologies of…

56. Historic photo of excavation work at Building 202, shows ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

56. Historic photo of excavation work at Building 202, shows facility with exhaust scrubber in foreground, February 24, 1969. On file at NASA Plumbrook Research Center, Sandusky, Ohio. NASA photo number C-69-712. - Rocket Engine Testing Facility, GRC Building No. 202, NASA Glenn Research Center, Cleveland, Cuyahoga County, OH

55. Historic photo of excavation work at Building 202, shows ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

55. Historic photo of excavation work at Building 202, shows facility with detention tank in foreground, February 24, 1969. On file at NASA Plumbrook Research Center, Sandusky, Ohio. NASA photo number C-69-711. - Rocket Engine Testing Facility, GRC Building No. 202, NASA Glenn Research Center, Cleveland, Cuyahoga County, OH

Supersonic air jets preserve tree roots in underground pipeline installation

Treesearch

Rob Gross; Michelle Julene

2002-01-01

Tree roots are often damaged during construction projects, particularly during trenching operations for pipeline installation. Although mechanical soil excavation using heavy equipment, such as an excavator or backhoe is considered the fastest the most economical method, it damages and destroys tree roots and can lead to unintentional tree loss, poor public relations,...

Environmental Assessment for Explosives Ordnance Disposal Proficiency Training Range at Wright-Patterson Air Force Base, Ohio

DTIC Science & Technology

2010-06-01

s) __ Test Plt(s) __ Test Trench(es) __ Deep Test(s) __ PZ or Humus Removal __ Testing/Excav. (strategy unknown) __ Mitigation/Block Excavation...Collection __ Surface Collection _Auger/Soil Corer _Shovel Test (s) .lL... Test Pit (s) _Test Trench (es) __ Deep Test (s) _ PZ or Humus Removal

The Li(f)e of the Self: Missing Persons and Auto/Archeological Excavations

ERIC Educational Resources Information Center

Burdick, Jake

2014-01-01

This article describes and enacts a process of autobiographical inquiry, auto/archeology, which seeks to address problematic confluences of memory and identity in reconstructing one's historical narrative. Drawing on curriculum theory and Lacanian psychoanalysis, the author describes a process of excavation in which understandings of a prior…

29 CFR 1926.650 - Scope, application, and definitions applicable to this subpart.

Code of Federal Regulations, 2010 CFR

2010-07-01

... excavation that are inclined away from the excavation so as to prevent cave-ins. The angle of incline... members of a trench shoring system placed in contact with the earth and usually positioned so that individual members do not contact each other. Uprights placed so that individual members are closely spaced...

The longevity of large pine snags in eastern Texas

Treesearch

Richard N. Conner; Daniel Saenz

2005-01-01

Habitat for cavity-nesting wildlife is closely tied to the availability of standing dead trees (snags). Large snags (>40 cm dbh) are particularly important because they provide cavity- excavation substrate for both large and small cavity excavators. Historically in the southern United States, common belief has been that the utility of pine (Pinus...

29 CFR 1926.650 - Scope, application, and definitions applicable to this subpart.

Code of Federal Regulations, 2012 CFR

2012-07-01

... excavation face or into an excavation, or from the collapse of adjacent structures. Protective systems... point from another, and is constructed from earth or from structural materials such as steel or wood... other members of the shoring system. Shield (Shield system) means a structure that is able to withstand...

29 CFR 1926.650 - Scope, application, and definitions applicable to this subpart.

Code of Federal Regulations, 2013 CFR

2013-07-01

... excavation face or into an excavation, or from the collapse of adjacent structures. Protective systems... point from another, and is constructed from earth or from structural materials such as steel or wood... other members of the shoring system. Shield (Shield system) means a structure that is able to withstand...

29 CFR 1926.650 - Scope, application, and definitions applicable to this subpart.

Code of Federal Regulations, 2014 CFR

2014-07-01

... excavation face or into an excavation, or from the collapse of adjacent structures. Protective systems... point from another, and is constructed from earth or from structural materials such as steel or wood... other members of the shoring system. Shield (Shield system) means a structure that is able to withstand...

29 CFR 1926.650 - Scope, application, and definitions applicable to this subpart.

Code of Federal Regulations, 2011 CFR

2011-07-01

... excavation face or into an excavation, or from the collapse of adjacent structures. Protective systems... point from another, and is constructed from earth or from structural materials such as steel or wood... other members of the shoring system. Shield (Shield system) means a structure that is able to withstand...

Task allocation in the tunneling behavior of workers of the formosan subterranean termite, coptotermes formosanus shiraki

USDA-ARS?s Scientific Manuscript database

Technical Abstract: There is variation in the tunneling behavior of workers of the Formosan subterranean termite, Coptotermes formosanus Shiraki, where most of the excavation is conducted by a small number of individuals in a group, while the majority of individuals do little or no excavation. This ...

77 FR 50044 - National Oil and Hazardous Substances Pollution Contingency Plan; National Priorities List...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-20

..., the USACE conducted additional subsurface soil sampling at four VPs in May and June 2003. Following... excavated. Post excavation sampling indicated all cleanup levels for these soils had been met. After five... license for radioactive materials was terminated by the NRC following Site decommissioning and the Site...

75 FR 78234 - Lock+TM

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-15

... project (Project No. 13780-000) would consist of: (1) An 85-foot-long, 100-foot-wide, 14-foot-deep excavated power canal; (2) a 95-foot-long, 100-foot-wide, 10-foot-deep excavated tailrace; (3) a 100-foot...)(iii) and the instructions on the Commission's Web site http://www.ferc.gov/docs-filing/efiling.asp...

The Effect of Projectile Density and Disruption on the Crater Excavation Flow-Field

NASA Technical Reports Server (NTRS)

Anderson, Jennifer L. B.; Schultz, P. H.

2005-01-01

The ejection parameters of material excavated by a growing crater directly relate to the subsurface excavation flow-field. The ejection angles and speeds define the end of subsurface material streamlines at the target surface. Differences in the subsurface flow-fields can be inferred by comparing observed ejection parameters of various impacts obtained using three-dimensional particle image velocimetry (3D PIV). The work presented here investigates the observed ejection speeds and angles of material ejected during vertical (90 impact angle) experimental impacts for a range of different projectile types. The subsurface flow-fields produced during vertical impacts are simple when compared with that of oblique impacts, affected primarily by the depth of the energy and momentum deposition of the projectile. This depth is highly controlled by the projectile/target density ratio and the disruption of the projectile (brittle vs. ductile deformation). Previous studies indicated that cratering efficiency and the crater diameter/depth ratio were affected by projectile disruption, velocity, and the projectile/target density ratio. The effect of these projectile properties on the excavation flow-field are examined by comparing different projectile materials.

Site remediation considerations and foundation excavation plan for the Walter Reed Army Institute of Research building, Forest Glen, Maryland

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hambley, D.F.; Harrison, W.; Foster, S.A.

1991-04-01

The US Army Corps of Engineers North Atlantic Division, Baltimore District (CENAB), intends to design and construct a medical and dental research facility for the Walter Reed Army Institute of Research (WRAIR) at the Walter Reed Army Medical Center (WRAMC) at Forest Glen, Maryland. Because almost 100% of the proposed building site is located on an uncontrolled landfill that was thought to possibly contain medical, toxic, radioactive, or hazardous waste, it was assumed that remediation of the site might be necessary prior to or in conjunction with excavation. To assess (1) the need for remediation and (2) the potential hazardsmore » to construction workers and the general population, the Baltimore District contracted with Argonne National Laboratory to undertake a site characterization and risk assessment and to develop a foundation-excavation plan. The results of the site characterization and a qualitative risk assessment have been presented in a previous report. This report presents the foundation-excavation plan. 38 refs., 16 figs., 11 tabs.« less

A novel use of the caesium-137 technique to estimate human interference and historical water level in a Mediterranean Temporary Pond.

PubMed

Foteinis, Spyros; Mpizoura, Katerina; Panagopoulos, Giorgos; Chatzisymeon, Efthalia; Kallithrakas-Kontos, Nikolaos; Manutsoglu, Emmanouil

2014-01-01

The sustainability of, and the effects of human pressures on, Omalos Mediterranean Temporary Pond (MTP), Chanea, Greece was assessed. The (137)Cs technique was used to identify alleged anthropogenic interference (excavation) in the studied area. It was found that about one third of the ponds bed surface material had been removed and disposed of on the northeast edge, confirming unplanned excavations that took place in the MTP area some years ago. Nonetheless, five years after the excavation, the MTP's ecosystem (flora and fauna) had recovered, which indicates that these small ecosystems are resilient to direct human pressures, like excavations. Moreover, with the (137)Cs technique it was possible to identify the historical water level of Omalos MTP, when the fallout from the Chernobyl accident reached this area, in May of 1986. Therefore, the (137)Cs technique can be useful in the identification of the historical water level of small MTPs and other ephemeral water bodies. Applications include the verification and validation of hydrological models. Copyright © 2013 Elsevier Ltd. All rights reserved.

Black-footed ferret digging activity in summer

USGS Publications Warehouse

Eads, David A.; Biggins, Dean E.; Marsh, Dustin; Millspaugh, Joshua J.; Livieri, Travis M.

2012-01-01

Black-footed ferrets (Mustela nigripes) excavate soil from prairie dog (Cynomys spp.) burrows, thereby creating characteristic soil deposits at burrow openings. These soil deposits have been observed only rarely in summer. We monitored adult ferrets during June–October of the years 2007 and 2008 on a 452-ha colony of black-tailed prairie dogs (Cynomys ludovicianus) in the Conata Basin, South Dakota. We located and identified ferret excavations during nighttime spotlight surveys for ferrets and daytime sampling of prairie dog burrow openings around locations where ferrets were located via spotlight. We accumulated 48 observations of in-process or recently completed ferret excavations during spotlight surveys (21 in 2007, 27 in 2008) and located 51 diggings during daytime burrow sampling (25 in 2007, 26 in 2008). We located diggings during 5.5% of spotlight observations, most frequently in July–August. These results collectively suggest ferrets may frequently excavate soil in summer, because prairie dogs frequently use soil to plug burrow openings and tunnels in defense against ferrets. Prairie dogs might frequently destroy soil deposits left by ferrets during summer, thereby reducing detection of diggings by biologists.

Reliability assessment of serviceability performance of braced retaining walls using a neural network approach

NASA Astrophysics Data System (ADS)

Goh, A. T. C.; Kulhawy, F. H.

2005-05-01

In urban environments, one major concern with deep excavations in soft clay is the potentially large ground deformations in and around the excavation. Excessive movements can damage adjacent buildings and utilities. There are many uncertainties associated with the calculation of the ultimate or serviceability performance of a braced excavation system. These include the variabilities of the loadings, geotechnical soil properties, and engineering and geometrical properties of the wall. A risk-based approach to serviceability performance failure is necessary to incorporate systematically the uncertainties associated with the various design parameters. This paper demonstrates the use of an integrated neural network-reliability method to assess the risk of serviceability failure through the calculation of the reliability index. By first performing a series of parametric studies using the finite element method and then approximating the non-linear limit state surface (the boundary separating the safe and failure domains) through a neural network model, the reliability index can be determined with the aid of a spreadsheet. Two illustrative examples are presented to show how the serviceability performance for braced excavation problems can be assessed using the reliability index.

Assessment of exposure to manganese in welding operations during the assembly of heavy excavation machinery accessories.

PubMed

Smargiassi, A; Baldwin, M; Savard, S; Kennedy, G; Mergler, D; Zayed, J

2000-10-01

Welder exposure to metals in various industrial sectors is poorly characterized. We had the opportunity to carry out an exploratory study to characterize manganese exposure in welding operations in a recently established Quebec factory that assembled accessories for heavy excavation machinery. Ten workers were sampled for total manganese for at least two consecutive days out of three followed by two consecutive days for respirable manganese (with a size selective sampler with a median cut-off of 4 microns), during a typical week in the summer of 1998. Parts being welded were characterized as large or small. Small parts were those being welded on tables during subassembly. Workers were divided into two groups according to the parts they were welding. Seventy-eight percent of the total manganese exposure levels of welding operations during the assembly of large accessories of heavy excavation machinery exceeded the manganese American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) of 0.20 mg/m3 (GM 0.24 mg/m3, n = 14) while none exceeded the TLV during the assembly of small pieces (GM 0.06 mg/m3, n = 8). Welding operations during the assembly of large heavy excavation machinery accessories may pose a significant health hazard. Considering the importance of task-related variables affecting exposure among workers, further studies are needed to better characterize exposure determinants of welding operations during the assembly of heavy excavation machinery accessories.

Excavationless Exterior Foundation Insulation Field Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schirber, T.; Mosiman, G.; Ojczyk, C.

Building science research supports installing exterior (soil side) foundation insulation as the optimal method to enhance the hygrothermal performance of new homes. With exterior foundation insulation, water management strategies are maximized while insulating the basement space and ensuring a more even temperature at the foundation wall. However, such an approach can be very costly and disruptive when applied to an existing home, requiring deep excavation around the entire house. The NorthernSTAR Building America Partnership team implemented an innovative, minimally invasive foundation insulation upgrade technique on an existing home. The approach consisted of using hydrovac excavation technology combined with a liquidmore » insulating foam. The team was able to excavate a continuous 4" wide by 4' to 5' deep trench around the entire house, 128 linear feet, except for one small part under the stoop that was obstructed with concrete debris. The combination pressure washer and vacuum extraction technology also enabled the elimination of large trenches and soil stockpiles normally produced by backhoe excavation. The resulting trench was filled with liquid insulating foam, which also served as a water-control layer of the assembly. The insulation was brought above grade using a liquid foam/rigid foam hybrid system and terminated at the top of the rim joist. Cost savings over the traditional excavation process ranged from 23% to 50%. The excavationless process could result in even greater savings since replacement of building structures, exterior features, utility meters, and landscaping would be minimal or non-existent in an excavationless process.« less

Excavationless Exterior Foundation Insulation Field Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schirber, T.; Mosiman, G.; Ojczyk, C.

Building science research supports installing exterior (soil side) foundation insulation as the optimal method to enhance the hygrothermal performance of new homes. With exterior foundation insulation, water management strategies are maximized while insulating the basement space and ensuring a more even temperature at the foundation wall. However, such an approach can be very costly and disruptive when applied to an existing home, requiring deep excavation around the entire house. The NorthernSTAR Building America Partnership team implemented an innovative, minimally invasive foundation insulation upgrade technique on an existing home. The approach consisted of using hydrovac excavation technology combined with liquid insulatingmore » foam. The team was able to excavate a continuous 4 inches wide by 4 feet to 5 feet deep trench around the entire house, 128 linear feet, except for one small part under the stoop that was obstructed with concrete debris. The combination pressure washer and vacuum extraction technology also enabled the elimination of large trenches and soil stockpiles normally produced by backhoe excavation. The resulting trench was filled with liquid insulating foam, which also served as a water-control layer of the assembly. The insulation was brought above grade using a liquid foam/rigid foam hybrid system and terminated at the top of the rim joist. Cost savings over the traditional excavation process ranged from 23% to 50%. The excavationless process could result in even greater savings since replacement of building structures, exterior features, utility meters, and landscaping would be minimal or non-existent in an excavationless process.« less

Comprehensive evaluation of high-steep slope stability and optimal high-steep slope design by 3D physical modeling

NASA Astrophysics Data System (ADS)

Lai, Xing-ping; Shan, Peng-fei; Cai, Mei-feng; Ren, Fen-hua; Tan, Wen-hui

2015-01-01

High-steep slope stability and its optimal excavation design in Shuichang open pit iron mine were analyzed based on a large 3D physical simulation technique. An optimal excavation scheme with a relatively steeper slope angle was successfully implemented at the northwest wall between Nos. 4 and 5 exploration lines of Shuichang Iron Mine, taking into account the 3D scale effect. The physico-mechanical properties of rock materials were obtained by laboratory tests conducted on sample cores from exploration drilling directly from the iron mine. A porous rock-like composite material was formed for the model, and the mechanical parameters of the material were assessed experimentally; specifically, the effect of water on the sample was quantitatively determined. We adopted an experimental setup using stiff modular applied static loading to carry out a visual excavation of the slope at a random depth. The setup was equipped with acoustic emission (AE) sensors, and the experiments were monitored by crack optical acquirement, ground penetrating radar, and close-field photogrammetry to investigate the mechanisms of rock-mass destabilization in the high-steep slope. For the complex study area, the model results indicated a clear correlation between the model's destabilization resulting from slope excavation and the collected monitoring information. During the model simulation, the overall angle of the slope increased by 1-6 degrees in different sections. Dramatically, the modeled excavation scheme saved over 80 million tons of rock from extraction, generating enormous economic and ecological benefits.

Freshly excavated fossil bones are best for amplification of ancient DNA.

PubMed

Pruvost, Mélanie; Schwarz, Reinhard; Correia, Virginia Bessa; Champlot, Sophie; Braguier, Séverine; Morel, Nicolas; Fernandez-Jalvo, Yolanda; Grange, Thierry; Geigl, Eva-Maria

2007-01-16

Despite the enormous potential of analyses of ancient DNA for phylogeographic studies of past populations, the impact these analyses, most of which are performed with fossil samples from natural history museum collections, has been limited to some extent by the inefficient recovery of ancient genetic material. Here we show that the standard storage conditions and/or treatments of fossil bones in these collections can be detrimental to DNA survival. Using a quantitative paleogenetic analysis of 247 herbivore fossil bones up to 50,000 years old and originating from 60 different archeological and paleontological contexts, we demonstrate that freshly excavated and nontreated unwashed bones contain six times more DNA and yield twice as many authentic DNA sequences as bones treated with standard procedures. This effect was even more pronounced with bones from one Neolithic site, where only freshly excavated bones yielded results. Finally, we compared the DNA content in the fossil bones of one animal, a approximately 3,200-year-old aurochs, excavated in two separate seasons 57 years apart. Whereas the washed museum-stored fossil bones did not permit any DNA amplification, all recently excavated bones yielded authentic aurochs sequences. We established that during the 57 years when the aurochs bones were stored in a collection, at least as much amplifiable DNA was lost as during the previous 3,200 years of burial. This result calls for a revision of the postexcavation treatment of fossil bones to better preserve the genetic heritage of past life forms.

Freshly excavated fossil bones are best for amplification of ancient DNA

PubMed Central

Pruvost, Mélanie; Schwarz, Reinhard; Correia, Virginia Bessa; Champlot, Sophie; Braguier, Séverine; Morel, Nicolas; Fernandez-Jalvo, Yolanda; Grange, Thierry; Geigl, Eva-Maria

2007-01-01

Despite the enormous potential of analyses of ancient DNA for phylogeographic studies of past populations, the impact these analyses, most of which are performed with fossil samples from natural history museum collections, has been limited to some extent by the inefficient recovery of ancient genetic material. Here we show that the standard storage conditions and/or treatments of fossil bones in these collections can be detrimental to DNA survival. Using a quantitative paleogenetic analysis of 247 herbivore fossil bones up to 50,000 years old and originating from 60 different archeological and paleontological contexts, we demonstrate that freshly excavated and nontreated unwashed bones contain six times more DNA and yield twice as many authentic DNA sequences as bones treated with standard procedures. This effect was even more pronounced with bones from one Neolithic site, where only freshly excavated bones yielded results. Finally, we compared the DNA content in the fossil bones of one animal, a ≈3,200-year-old aurochs, excavated in two separate seasons 57 years apart. Whereas the washed museum-stored fossil bones did not permit any DNA amplification, all recently excavated bones yielded authentic aurochs sequences. We established that during the 57 years when the aurochs bones were stored in a collection, at least as much amplifiable DNA was lost as during the previous 3,200 years of burial. This result calls for a revision of the postexcavation treatment of fossil bones to better preserve the genetic heritage of past life forms. PMID:17210911

Omaha Soil Mixing Study: Redistribution of Lead in ...

EPA Pesticide Factsheets

Urban soils within the Omaha Lead Superfund Site have been contaminated with lead (Pb) from atmospheric deposition of particulate materials from lead smelting and recycling activities. In May of 2009 the Final Record of Decision stated that any residential soil exceeding the preliminary remediation goal (PRG; 400 mgPb kg-1soil) would be excavated, backfilled and re-vegetated. The remedial action entailed excavating contaminated soil in the top 12 inches and excavation could stop when the concentration of soil Pb was less than 400 mg kg-1 in the top 12 inches, or less than 1200 mg kg-1 at depths greater than 1 ft. After removal of the contaminated soil, clean backfill was applied and a grass lawn was replanted. A depth of 12 inches was based on the assumption that Pb-contaminated soil at depth greater than 1 ft would not represent a future risk (ASTDR Health Consult, 2004). This assumption was based on the principal that mixing and other factors encountered during normal excavation practices would not result in Pb surface concentrations greater than the PRG. The goal of the current study was to investigate the redistribution of Pb in remediated residential surface soils after typical homeowner earth-disturbing activities in the OLS Site. Of specific interest to the region for protection of human health is determining whether soil mixing associated with normal homeowner excavation practices results in surface Pb concentrations greater than the preliminary r

Florida Harvester Ant Nest Architecture, Nest Relocation and Soil Carbon Dioxide Gradients

PubMed Central

Tschinkel, Walter R.

2013-01-01

Colonies of the Florida harvester ant, Pogonomyrmex badius, excavate species-typical subterranean nests up the 3 m deep with characteristic vertical distribution of chamber area/shape, spacing between levels and vertical arrangement of the ants by age and brood stage. Colonies excavate and occupy a new nest about once a year, and doing so requires that they have information about the depth below ground. Careful excavation and mapping of vacated and new nests revealed that there was no significant difference between the old and new nests in any measure of nest size, shape or arrangement. Colonies essentially built a replicate of the just-vacated nest (although details differed), and they did so in less than a week. The reason for nest relocation is not apparent. Tschinkel noted that the vertical distribution of chamber area, worker age and brood type was strongly correlated to the soil carbon dioxide gradient, and proposed that this gradient serves as a template for nest excavation and vertical distribution. To test this hypothesis, the carbon dioxide gradient of colonies that were just beginning to excavate a new nest was eliminated by boring 6 vent holes around the forming nest, allowing the soil CO2 to diffuse into the atmosphere and eliminating the gradient. Sadly, neither the nest architecture nor the vertical ant distribution of vented nests differed from either unvented control or from their own vacated nest. In a stronger test, workers excavated a new nest under a reversed carbon dioxide gradient (high concentration near the surface, low below). Even under these conditions, the new and old nests did not differ significantly, showing that the soil carbon dioxide gradient does not serve as a template for nest construction or vertical worker distribution. The possible importance of soil CO2 gradients for soil-dwelling animals is discussed. PMID:23555829

Forecasting and prevention of water inrush during the excavation process of a diversion tunnel at the Jinping II Hydropower Station, China.

PubMed

Hou, Tian-Xing; Yang, Xing-Guo; Xing, Hui-Ge; Huang, Kang-Xin; Zhou, Jia-Wen

2016-01-01

Estimating groundwater inflow into a tunnel before and during the excavation process is an important task to ensure the safety and schedule during the underground construction process. Here we report a case of the forecasting and prevention of water inrush at the Jinping II Hydropower Station diversion tunnel groups during the excavation process. The diversion tunnel groups are located in mountains and valleys, and with high water pressure head. Three forecasting methods are used to predict the total water inflow of the #2 diversion tunnel. Furthermore, based on the accurate estimation of the water inrush around the tunnel working area, a theoretical method is presented to forecast the water inflow at the working area during the excavation process. The simulated results show that the total water flow is 1586.9, 1309.4 and 2070.2 m(3)/h using the Qshima method, Kostyakov method and Ochiai method, respectively. The Qshima method is the best one because it most closely matches the monitoring result. According to the huge water inflow into the #2 diversion tunnel, reasonable drainage measures are arranged to prevent the potential disaster of water inrush. The groundwater pressure head can be determined using the water flow velocity from the advancing holes; then, the groundwater pressure head can be used to predict the possible water inflow. The simulated results show that the groundwater pressure head and water inflow re stable and relatively small around the region of the intact rock mass, but there is a sudden change around the fault region with a large water inflow and groundwater pressure head. Different countermeasures are adopted to prevent water inrush disasters during the tunnel excavation process. Reasonable forecasting the characteristic parameters of water inrush is very useful for the formation of prevention and mitigation schemes during the tunnel excavation process.

Evaluation of the Efficacy of Caries Removal Using Polymer Bur, Stainless Steel Bur, Carisolv, Papacarie - An Invitro Comparative Study.

PubMed

Divya, Gaddam; Prasad, Madhu Ghanashyam; Vasa, Aron Arun Kumar; Vasanthi, Done; Ramanarayana, Boyapati; Mynampati, Praffulla

2015-07-01

Dental caries continues to affect a significant portion of the world population and treatment of the decay is associated with pain by many patients. Intervention and application of rotary instruments for treatment of carious lesions has often resulted in considerable removal of tooth structure. Chemo-mechanical method, a minimal invasive technique for caries removal was developed to overcome these shortcomings. This innovative method seems to be efficient in removing infected dentine without altering the healthy dental tissue or harming the adjacent oral mucosa. To evaluate the efficacy and efficiency of Caries removal Using Polymer Bur, Stainless Steel Bur, Carisolv and Papacarie. A total of 120 sectioned specimens were obtained from 60 extracted teeth. Each tooth was sectioned mesiodistally in the center of the carious lesion so that two halves (buccal and lingual or palatal) having equal sized carious lesions are compared. The sectioned specimens were subdivided into four groups (Polymer Bur, Stainless Steel Bur, Carisolv, Papacarie) allotting 30 specimens to each for caries excavation. One-way ANOVA, Chi-square test analysis was done for comparison between groups which showed significant results with Stainless Steel Bur excavation taking less mean time when compared to other agents and Polymer Bur showed more amount of bacterial remnants after excavation whereas Carisolv and Papacarie were efficient with less dentinal tubule destruction and bacterial remnants after excavation. Further inter comparison between groups was done using Paired t-test and Fischer's Exact-test. The Mean time taken by Stainless Steel Bur excavation was found to be less and caused more amount of dentinal tubule destruction when compared to Polymer Bur, Carisolv and Papacarie. Chemo-mechanical methods found to be more efficient with lesser amount of bacterial remnants and dentinal tubule destruction after caries excavation when compared to conventional methods.

Evaluation of the Efficacy of Caries Removal Using Polymer Bur, Stainless Steel Bur, Carisolv, Papacarie – An Invitro Comparative Study

PubMed Central

Prasad, Madhu Ghanashyam; Vasa, Aron Arun Kumar; Vasanthi, Done; Ramanarayana, Boyapati; Mynampati, Praffulla

2015-01-01

Context Dental caries continues to affect a significant portion of the world population and treatment of the decay is associated with pain by many patients. Intervention and application of rotary instruments for treatment of carious lesions has often resulted in considerable removal of tooth structure. Chemo-mechanical method, a minimal invasive technique for caries removal was developed to overcome these shortcomings. This innovative method seems to be efficient in removing infected dentine without altering the healthy dental tissue or harming the adjacent oral mucosa. Aim To evaluate the efficacy and efficiency of Caries removal Using Polymer Bur, Stainless Steel Bur, Carisolv and Papacarie. Materials and Methods A total of 120 sectioned specimens were obtained from 60 extracted teeth. Each tooth was sectioned mesiodistally in the center of the carious lesion so that two halves (buccal and lingual or palatal) having equal sized carious lesions are compared. The sectioned specimens were subdivided into four groups (Polymer Bur, Stainless Steel Bur, Carisolv, Papacarie) allotting 30 specimens to each for caries excavation. Results One-way ANOVA, Chi-square test analysis was done for comparison between groups which showed significant results with Stainless Steel Bur excavation taking less mean time when compared to other agents and Polymer Bur showed more amount of bacterial remnants after excavation whereas Carisolv and Papacarie were efficient with less dentinal tubule destruction and bacterial remnants after excavation. Further inter comparison between groups was done using Paired t-test and Fischer’s Exact-test. Conclusion The Mean time taken by Stainless Steel Bur excavation was found to be less and caused more amount of dentinal tubule destruction when compared to Polymer Bur, Carisolv and Papacarie. Chemo-mechanical methods found to be more efficient with lesser amount of bacterial remnants and dentinal tubule destruction after caries excavation when compared to conventional methods. PMID:26393204

Distribution and geochemical characterization of coalbed gases at excavation fields at natural analogue site area Velenje Basin, Slovenia

NASA Astrophysics Data System (ADS)

Kanduč, Tjaša; Žigon, Stojan; Grassa, Fausto; Sedlar, Jerneja; Zadnik, Ivo; Zavšek, Simon

2016-04-01

Unconventional gas resources, including coal bed methane and shale gas, are a growing part of the global energy mix, which has changed the economic and strategic picture for gas consuming and producing countries, including the USA, China and Australia that, together are responsible for around half the currently recoverable unconventional gas resources. However, CBM production was often hindered by low permeability and mineralization in cleats and fractures, necessitating the development of cost effective horizontal drilling and completion techniques. Geochemical and isotopic monitoring of coalbed gases at excavation fields in Velenje Basin started in year 2000, with the aim to obtain better insights into the origin of coalbed gases. Results from active excavation fields in the mining areas Pesje and Preloge in the year period 2014-2015 are presented in this study. Composition and isotopic composition of coalbed gases were determined with mass - spectrometric methods. The chemical (methane, carbon dioxide, nitrogen) and isotopic composition of carbon in methane and carbon dioxide in the Velenje Basin vary and depend on the composition of the source of coalbed gas before excavation, advancement of the working face, depth of the longwall face, pre-mining activity and newly mined activity. The basic gas components determined in excavation fields are carbon dioxide and methane. Knowledge of the stable isotope geochemistry of coal bed and shale gas and the related production water is essential to determine not only gas origins but also the dominant methanogenic pathway in the case of microbial gas. Concentrations of methane at active excavation fields are changing from 1.8 to 63.9 %, concentrations of carbon dioxide are changing from 36.1 to 98.2% and CDMI (Carbon Dioxide Methane Index) index from 0.2 to 100 %. Isotopic composition of carbon dioxide is changing from -11.0 to -1.9‰ , isotopic composition of methane from -71.8 to -43.3‰ , isotopic composition of deuterium in methane from -343.9 to -223.1‰ , respectively. Further, these characteristics of methane have been compared with those observed in other coal sedimentary basins worldwide. The isotopic compositions of carbon and hydrogen in methane in the excavation fields show its biogenic origin, while a high Carbon Dioxide Methane Index (CDMI index) indicates the bacterial and endogenic origin of carbon dioxide.

Applying the seismic interferometry method to vertical seismic profile data using tunnel excavation noise as source

NASA Astrophysics Data System (ADS)

Jurado, Maria Jose; Teixido, Teresa; Martin, Elena; Segarra, Miguel; Segura, Carlos

2013-04-01

In the frame of the research conducted to develop efficient strategies for investigation of rock properties and fluids ahead of tunnel excavations the seismic interferometry method was applied to analyze the data acquired in boreholes instrumented with geophone strings. The results obtained confirmed that seismic interferometry provided an improved resolution of petrophysical properties to identify heterogeneities and geological structures ahead of the excavation. These features are beyond the resolution of other conventional geophysical methods but can be the cause severe problems in the excavation of tunnels. Geophone strings were used to record different types of seismic noise generated at the tunnel head during excavation with a tunnelling machine and also during the placement of the rings covering the tunnel excavation. In this study we show how tunnel construction activities have been characterized as source of seismic signal and used in our research as the seismic source signal for generating a 3D reflection seismic survey. The data was recorded in vertical water filled borehole with a borehole seismic string at a distance of 60 m from the tunnel trace. A reference pilot signal was obtained from seismograms acquired close the tunnel face excavation in order to obtain best signal-to-noise ratio to be used in the interferometry processing (Poletto et al., 2010). The seismic interferometry method (Claerbout 1968) was successfully applied to image the subsurface geological structure using the seismic wave field generated by tunneling (tunnelling machine and construction activities) recorded with geophone strings. This technique was applied simulating virtual shot records related to the number of receivers in the borehole with the seismic transmitted events, and processing the data as a reflection seismic survey. The pseudo reflective wave field was obtained by cross-correlation of the transmitted wave data. We applied the relationship between the transmission response and the reflection response for a 1D multilayer structure, and next 3D approach (Wapenaar 2004). As a result of this seismic interferometry experiment the 3D reflectivity model (frequencies and resolution ranges) was obtained. We proved also that the seismic interferometry approach can be applied in asynchronous seismic auscultation. The reflections detected in the virtual seismic sections are in agreement with the geological features encountered during the excavation of the tunnel and also with the petrophysical properties and parameters measured in previous geophysical borehole logging. References Claerbout J.F., 1968. Synthesis of a layered medium from its acoustic transmision response. Geophysics, 33, 264-269 Flavio Poletto, Piero Corubolo and Paolo Comeli.2010. Drill-bit seismic interferometry whith and whitout pilot signals. Geophysical Prospecting, 2010, 58, 257-265. Wapenaar, K., J. Thorbecke, and D. Draganov, 2004, Relations between reflection and transmission responses of three-dimensional inhomogeneous media: Geophysical Journal International, 156, 179-194.

40. Photocopied August 1978. EXCAVATION IN THE FOREBAY, VIEW LOOKING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

40. Photocopied August 1978. EXCAVATION IN THE FOREBAY, VIEW LOOKING WEST, MARCH 31, 1899. THE EQUIPMENT USED IN THIS AREA WAS MAINLY MAN-OR HORSE-POWERED SINCE SOIL CONDITIONS HERE (NEAR THE RIVER) WERE TOO SOFT TO PERMIT HEAVY EQUIPMENT. (28) - Michigan Lake Superior Power Company, Portage Street, Sault Ste. Marie, Chippewa County, MI

3. View of partially excavated mill ruins looking NW showing ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. View of partially excavated mill ruins looking NW showing unidentified pit in right foreground, masonry base for steam engine and cane mill in left center, purging house and chimney in background. - Hacienda Azucarera La Esperanza, Mill (Ruins), 2.65 miles North of PR Route 2 Bridge Over Manati River, Manati, Manati Municipio, PR

Use of external nesting boxes by roosting red-cockaded woodpeckers

Treesearch

William E. Taylor; Robert G. Hooper

2004-01-01

Red-cockaded woodpeckers (Picoides borealis) roost year-round in cavities they excavate in living pine trees. Cavity excavation is a lengthy process (Conner and Rudolph 1995a) and sometimes a member of a family group does not have an available cavity for roosting within its resident cluster of cavity trees. Woodpeckers without a cavity either roost...

The longevity of large pine snags in eastern Texas

Treesearch

Richard N. Conner; Daniel Saenz

2005-01-01

Habitat for cavity-nesting wildlife is closely tied to the availability of standing dead trees (snags). Large snags (>40 cm dbh) are particularly important because they provide cavity- excavation substrate for both large and small cavity excavators. Historically in the southern United States, common belief has been that the utility of pine (Pinus spp.) snags for...

The Freeze-Drying of Wet and Waterlogged Materials from Archaeological Excavations

ERIC Educational Resources Information Center

Watson, Jacqui

2004-01-01

Large quantities of wood and leather have been found in the waterlogged layers on archaeological excavations. Centuries of burial, however, have left these materials in a very degraded and vulnerable state such that if they dry out they will fall apart. This paper discusses the physics behind the freeze-drying techniques that allow the…

Excavating Silences and Tensions of Agency|Passivity in Science Education Reform

ERIC Educational Resources Information Center

Rivera Maulucci, Maria S.

2010-01-01

I reflect on studies by Rodriguez and Carlone, Haun-Frank, and Kimmel to emphasize the ways in which they excavate silences in the science education literature related to linguistic and cultural diversity and situating the problem of reform in teachers rather than contextual factors, such as traditional schooling discourses and forces that serve…

[Parasite eggs identified in material from archaeological excavations in Ribe (the viking age) (author's transl)].

PubMed

Nansen, P; Jorgensen, R J

1977-06-01

Eggs of Fasciola hepatica, Ascaris sp., Taenia sp., and Trichuris sp. have been demonstrated in archaeological excavations from the early viking period (750--800 A.D.) in Ribe, the oldest urban society of Denmark. The origin of the faecal material is discussed. The parasitological examinations are continued and extended.

Effects of Metric Change on Workers’ Tools and Training.

DTIC Science & Technology

1981-07-01

understanding of the metric system, and particularly a lack of fluency in converting customary measurements to metric measuremerts, may increase the...assembly, installing, and repairing occupations 84 Painting, plastering, waterproofing, cementing , and related occupations 85 Excavating, grading... cementing , and related occupations 85 Excavating, grading, paving, and related occupations 86 Construction occupations, n.e.c. 89 Structural work

Does red-cockaded woodpecker excavation of resin wells increase risk of bark beetle infestation of cavity trees?

Treesearch

Richard N. Conner; Daniel Saenz; D. Craig Rudolph; William G. Ross; David L. Kulhavy; Robert N. Coulson

2001-01-01

The red-cockaded woodpecker (Picoides borealis) is unique among North American woodpeckers in that it nests and roosts almost exclusively in living pines (Pinus spp.) The red-cockaded woodpecker makes daily excavations at small wounds, termed "resin wells," around the cavity entrance and on the bole of the cavity tree...

Complete excavation and mapping of a Texas leafcutting ant nest

Treesearch

John C. Moser

2006-01-01

A medium-sized nest of the Texas leafcutting ant, Atta texana (Buckley), in northern Louisiana was excavated completely, and a three-dimensional model of its external and subterranean features was constructed. In total, 97 fungus gardens, 27 dormancy cavities, and 45 detritus cavities were located. At the lower center of the funnel-shaped nest was a...

Snag Condition and Woodpecker Foraging Ecology in a Bottomland Hardwood Forest

Treesearch

Richard N. Conner; Stanley D. Jones; Gretchen D. Jones

1994-01-01

We studied woodpecker foraging behavior, snag quality, and surrounding habitat in a bottomland hardwood forest in the Stephen F. Austin Experimental Forest from December 1984 through November 1986. The amount and location of woodpecker foraging excavations indicated that woodpeckers excavated mainly at the well-decayed tops and bases of snags. Woodpeckers preferred to...

Foraging plasticity by a keystone excavator, the white-headed woodpecker, in managed forests: Are there consequences for productivity?

Treesearch

Teresa J. Lorenz; Kerri T. Vierling; Jeffrey M. Kozma; Janet E. Millard

2016-01-01

Information on the foraging ecology of animals is important for conservation and management, particularly for keystone species whose presence affects ecosystem health. We examined foraging by an at-risk cavity excavator, the white-headed woodpecker (Picoides albolarvatus). The foraging needs of this species are used to inform management of...

75 FR 78236 - Lock+TM

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-15

...-foot-wide, 20-foot-deep excavated power canal; (2) a 55-foot-long, 65-foot-wide, 8-foot-deep excavated... 18 CFR 385.2001(a)(1)(iii) and the instructions on the Commission's Web site http://www.ferc.gov/docs... Web site at http://www.ferc.gov/docs-filing/elibrary.asp . Enter the docket number (P-13743-000, 13753...

The Montana ALE (Autonomous Lunar Excavator) Systems Engineering Report

NASA Technical Reports Server (NTRS)

Hull, Bethanne J.

2012-01-01

On May 2 1-26, 20 12, the third annual NASA Lunabotics Mining Competition will be held at the Kennedy Space Center in Florida. This event brings together student teams from universities around the world to compete in an engineering challenge. Each team must design, build and operate a robotic excavator that can collect artificial lunar soil and deposit it at a target location. Montana State University, Bozeman, is one of the institutions selected to field a team this year. This paper will summarize the goals of MSU's lunar excavator project, known as the Autonomous Lunar Explorer (ALE), along with the engineering process that the MSU team is using to fulfill these goals, according to NASA's systems engineering guidelines.

Key techniques and risk management for the application of the Pile-Beam-Arch (PBA) excavation method: a case study of the Zhongjie subway station.

PubMed

Guan, Yong-ping; Zhao, Wen; Li, Shen-gang; Zhang, Guo-bin

2014-01-01

The design and construction of shallow-buried tunnels in densely populated urban areas involve many challenges. The ground movements induced by tunneling effects pose potential risks to infrastructure such as surface buildings, pipelines, and roads. In this paper, a case study of the Zhongjie subway station located in Shenyang, China, is examined to investigate the key construction techniques and the influence of the Pile-Beam-Arch (PBA) excavation method on the surrounding environment. This case study discusses the primary risk factors affecting the environmental safety and summarizes the corresponding risk mitigation measures and key techniques for subway station construction using the PBA excavation method in a densely populated urban area.

Landfill aeration for emission control before and during landfill mining.

PubMed

Raga, Roberto; Cossu, Raffaello; Heerenklage, Joern; Pivato, Alberto; Ritzkowski, Marco

2015-12-01

The landfill of Modena, in northern Italy, is now crossed by the new high velocity railway line connecting Milan and Bologna. Waste was completely removed from a part of the landfill and a trench for the train line was built. With the aim of facilitating excavation and further disposal of the material extracted, suitable measures were defined. In order to prevent undesired emissions into the excavation area, the aerobic in situ stabilisation by means of the Airflow technology took place before and during the Landfill Mining. Specific project features involved the pneumatic leachate extraction from the aeration wells (to keep the leachate table low inside the landfill and increase the volume of waste available for air migration) and the controlled moisture addition into a limited zone, for a preliminary evaluation of the effects on process enhancement. Waste and leachate were periodically sampled in the landfill during the aeration before the excavation, for quality assessment over time; the evolution of biogas composition in the landfill body and in the extraction system for different plant set-ups during the project was monitored, with specific focus on uncontrolled migration into the excavation area. Waste biological stability significantly increased during the aeration (waste respiration index dropped to 33% of the initial value after six months). Leachate head decreased from 4 to 1.5m; leachate recirculation tests proved the beneficial effects of moisture addition on temperature control, without hampering waste aerobization. Proper management of the aeration plant enabled the minimization of uncontrolled biogas emissions into the excavation area. Copyright © 2015 Elsevier Ltd. All rights reserved.

Geoenvironmental studies on conservation of archaeological sites at Siwa oasis, Egypt

NASA Astrophysics Data System (ADS)

Ibrahim, Hani A. M.; Kamh, Gamal E.

2006-02-01

Siwa oasis is located in the extreme western part of the Egyptian western desert. There are several archaeological sites in the oasis; the most distinct ones are Alexander the Great temple at Aghormi hill and the Gebel El Mota tomb excavations. They have suffered due to deterioration and cracks of different kinds and some parts are getting worse as rock falls occur. From field inspection and lab analysis, it is clear that lithology plays an important role on the extent of damage. Alexander the Great temple was built over the northern edge of Aghormi hill, which consists of two distinct beds—an upper limestone bed and a lower shale one. From field survey and laboratory analysis, the shale is considered as a high expanded bed and weak in its bearing capacity, as its clay content (mainly smectite) experienced swelling due to wetting from the ground water spring underneath. Consequently, the upper limestone bed suffered from map cracking associated with rock falls due to the differential settlement of the swelled lower shale one. The temple was threatened by slope instability and had experienced many cracks. At Gabal El Mota tomb excavations, it was noticed that a comparison of tombs of the same opening size revealed that those that excavated on shale beds had cracked much more than those that excavated on limestone. This may be attributed to the low bearing capacity of excavated shale walls. The remedial measures suggested to overcome the stability problems on these archaeological sites are grouting or construction of retaining walls.

Microseism Induced by Transient Release of In Situ Stress During Deep Rock Mass Excavation by Blasting

NASA Astrophysics Data System (ADS)

Yang, Jianhua; Lu, Wenbo; Chen, Ming; Yan, Peng; Zhou, Chuangbing

2013-07-01

During deep rock mass excavation with the method of drill and blast, accompanying the secession of rock fragments and the formation of a new free surface, in situ stress on this boundary is suddenly released within several milliseconds, which is termed the transient release of in situ stress. In this process, enormous strain energy around the excavation face is instantly released in the form of kinetic energy and it inevitably induces microseismic events in surrounding rock masses. Thus, blasting excavation-induced microseismic vibrations in high-stress rock masses are attributed to the combined action of explosion and the transient release of in situ stress. The intensity of stress release-induced microseisms, which depends mainly on the magnitude of the in situ stress and the dimension of the excavation face, is comparable to that of explosion-induced vibrations. With the methods of time-energy density analysis, amplitude spectrum analysis, and finite impulse response (FIR) digital filter, microseismic vibrations induced by the transient release of in situ stress were identified and separated from recorded microseismic signals during a blast of deep rock masses in the Pubugou Hydropower Station. The results show that the low-frequency component in the microseismic records results mainly from the transient release of in situ stress, while the high-frequency component originates primarily from explosion. In addition, a numerical simulation was conducted to demonstrate the occurrence of microseismic events by the transient release of in situ stress, and the results seem to have confirmed fairly well the separated vibrations from microseismic records.

Building America Case Study: Excavationless Exterior-Side Foundation Insulation for Existing Homes, Minneapolis, Minnesota (Fact Sheet)

DOE Office of Scientific and Technical Information (OSTI.GOV)

NorthernSTAR

Building science research supports installing exterior (soil side) foundation insulation as the optimal method to enhance the hygrothermal performance of new homes. With exterior foundation insulation, water management strategies are maximized while insulating the basement space and ensuring a more even temperature at the foundation wall. However, such an approach can be very costly and disruptive when applied to an existing home, requiring deep excavation around the entire house. The NorthernSTAR Building America Partnership team implemented an innovative, minimally invasive foundation insulation upgrade technique on an existing home. The approach consisted of using hydrovac excavation technology combined with a liquidmore » insulating foam. The team was able to excavate a continuous 4" wide by 4' to 5' deep trench around the entire house, 128 linear feet, except for one small part under the stoop that was obstructed with concrete debris. The combination pressure washer and vacuum extraction technology also enabled the elimination of large trenches and soil stockpiles normally produced by backhoe excavation. The resulting trench was filled with liquid insulating foam, which also served as a water-control layer of the assembly. The insulation was brought above grade using a liquid foam/rigid foam hybrid system and terminated at the top of the rim joist. Cost savings over the traditional excavation process ranged from 23% to 50%. The excavationless process could result in even greater savings since replacement of building structures, exterior features, utility meters, and landscaping would be minimal or non-existent in an excavationless process.« less

Extreme cellular adaptations and cell differentiation required by a cyanobacterium for carbonate excavation

PubMed Central

Guida, Brandon Scott; Garcia-Pichel, Ferran

2016-01-01

Some cyanobacteria, known as euendoliths, excavate and grow into calcium carbonates, with their activity leading to significant marine and terrestrial carbonate erosion and to deleterious effects on coral reef and bivalve ecology. Despite their environmental relevance, the mechanisms by which they can bore have remained elusive and paradoxical, in that, as oxygenic phototrophs, cyanobacteria tend to alkalinize their surroundings, which will encourage carbonate precipitation, not dissolution. Therefore, cyanobacteria must rely on unique adaptations to bore. Studies with the filamentous euendolith, Mastigocoleus testarum, indicated that excavation requires both cellular energy and transcellular calcium transport, mediated by P-type ATPases, but the cellular basis for this phenomenon remains obscure. We present evidence that excavation in M. testarum involves two unique cellular adaptations. Long-range calcium transport is based on active pumping at multiple cells along boring filaments, orchestrated by the preferential localization of calcium ATPases at one cell pole, in a ring pattern, facing the cross-walls, and by repeating this placement and polarity, a pattern that breaks at branching and apical cells. In addition, M. testarum differentiates specialized cells we call calcicytes, that which accumulate calcium at concentrations more than 500-fold those found in other cyanobacteria, concomitantly and drastically lowering photosynthetic pigments and enduring severe cytoplasmatic alkalinization. Calcicytes occur commonly, but not exclusively, in apical parts of the filaments distal to the excavation front. We suggest that calcicytes allow for fast calcium flow at low, nontoxic concentrations through undifferentiated cells by providing buffering storage for excess calcium before final excretion to the outside medium. PMID:27140633

COMPARISON OF THE EXTENT OF TREATMENT OF MTBE AND BENZENE BY ACTIVE REMEDIAL TECHNOLOGY AT UST SITES IN KANSAS

EPA Science Inventory

Data were collected from 63 sites in Kansas where technology for active cleanup of gasoline contamination had been implemented; SVE and AS was used at 39 sites, SVE alone at 11 sites, SVE an AS and excavation at 6 sites, SVE and product recovery at 3 sites, excavation alone at 2 ...

Guidance for Low-Level Radioactive Waste (LLRW) and Mixed Waste (MW) Treatment and Handling

DTIC Science & Technology

1997-06-30

7-2 7-1 Excavation of Contaminated Soils . . . . . . . . 7-3 7-1 Excavation of Contaminated Sediments...becomes only as radioactive as natural soil . By comparison, many other potential y hazardous, but nonradioactive, chemical wastes like lead, silver...solutions and cleanup materials, engine oils and grease, epoxies and resins, laser dyes, paint residues, photo- graphic materials, soils , asphalts

Simulating cut-to-length harvesting operations in Appalachian hardwoods

Treesearch

Jingxin Wang; Chris B. LeDoux; Yaoxiang Li

2005-01-01

Cut-to-length (CTL) harvesting systems involving small and large harvesters and a forwarder were simulated using a modular computer simulation model. The two harvesters simulated were a modified John Deere 988 tracked excavator with a single grip sawhead and a Timbco T425 based excavator with a single grip sawhead. The forwarder used in the simulations was a Valmet 524...

Characteristics of snags containing excavated cavities in northern Arizona mixed-conifer and ponderosa pine forests

Treesearch

Joseph L. Ganey; Scott C. Vojta

2004-01-01

Snags provide an important resource for a rich assemblage of cavity-nesting birds in the southwestern United States. To expand our knowledge of snag use by cavity-nesting birds in this region, we documented characteristics of snags with and without excavated cavities in mixed-conifer and ponderosa pine (Pinus ponderosa Dougl. ex Laws) forest in north...

Red-cockaded woodpecker nest-cavity selection: relationships with cavity age and resin production

Treesearch

Richard N. Conner; Daniel Saenz; D. Craig Rudolph; William G. Ross; David L. Kulhavy

1998-01-01

The authors evaluated selection of nest sites by male red-cockaded woodpeckers (Picoides borealis) in Texas relative to the age of the cavity when only cavities excavated by the woodpeckers were available and when both naturally excavated cavities and artificial cavities were available. They also evaluated nest-cavity selection relative to the ability of naturally...

29 CFR Appendix B to Subpart P of... - Sloping and Benching

Code of Federal Regulations, 2013 CFR

2013-07-01

... excavations 20 feet or less in depth made in layered soils shall have a maximum allowable slope for each layer.... Distress means that the soil is in a condition where a cave-in is imminent or is likely to occur. Distress... 24 hours that an excavation is open. (c) Requirements—(1) Soil classification. Soil and rock deposits...

29 CFR Appendix B to Subpart P of... - Sloping and Benching

Code of Federal Regulations, 2012 CFR

2012-07-01

... excavations 20 feet or less in depth made in layered soils shall have a maximum allowable slope for each layer.... Distress means that the soil is in a condition where a cave-in is imminent or is likely to occur. Distress... 24 hours that an excavation is open. (c) Requirements—(1) Soil classification. Soil and rock deposits...

29 CFR Appendix B to Subpart P of... - Sloping and Benching

Code of Federal Regulations, 2014 CFR

2014-07-01

... excavations 20 feet or less in depth made in layered soils shall have a maximum allowable slope for each layer.... Distress means that the soil is in a condition where a cave-in is imminent or is likely to occur. Distress... 24 hours that an excavation is open. (c) Requirements—(1) Soil classification. Soil and rock deposits...

29 CFR Appendix B to Subpart P of... - Sloping and Benching

Code of Federal Regulations, 2011 CFR

2011-07-01

... excavations 20 feet or less in depth made in layered soils shall have a maximum allowable slope for each layer.... Distress means that the soil is in a condition where a cave-in is imminent or is likely to occur. Distress... 24 hours that an excavation is open. (c) Requirements—(1) Soil classification. Soil and rock deposits...

29 CFR Appendix B to Subpart P of... - Sloping and Benching

Code of Federal Regulations, 2010 CFR

2010-07-01

... excavations 20 feet or less in depth made in layered soils shall have a maximum allowable slope for each layer.... Distress means that the soil is in a condition where a cave-in is imminent or is likely to occur. Distress... 24 hours that an excavation is open. (c) Requirements—(1) Soil classification. Soil and rock deposits...

Clinical Evaluation of Ozone on Dentinal Lesions in Young Permanent Molars using the Stepwise Excavation.

PubMed

Safwat, Osama; Elkateb, Mona; Dowidar, Karin; El Meligy, Omar

To evaluate the clinical changes in dentin of deep carious lesions in young permanent molars, following ozone application with and without the use of a remineralizing solution, using the stepwise excavation. The sample included 162 first permanent immature molars, showing deep occlusal carious cavities that were indicated for indirect pulp capping. Teeth were divided into 2 main groups according to the method of ozone treatment. Each group was further subdivided equally into test and control subgroups. Following caries excavation, color, consistency and DIAGNOdent assessments of dentin were evaluated after 6 and 12 months. Regarding dentin color and consistency, no significant differences were observed following ozone application, with and without a remineralizing solution. There were no significant differences between ozone treatment, and calcium hydroxide during the different evaluation periods, except in group I cases after 6 months, concerning the dentin color. The DIAGNOdent values were significantly reduced following ozone application, with or without a remineralizing solution, as well as between test and control cases in group I after 6 months. Ozone application through the stepwise excavation had no significant effect on dentin color and consistency in young permanent molars. DIAGNOdent was unreliable in monitoring caries activity.

Endoscopic en bloc resection of an exophytic gastrointestinal stromal tumor with suction excavation technique

PubMed Central

Choi, Hyuk Soon; Chun, Hoon Jai; Kim, Kyoung-Oh; Kim, Eun Sun; Keum, Bora; Jeen, Yoon-Tae; Lee, Hong Sik; Kim, Chang Duck

2016-01-01

Here, we report the first successful endoscopic resection of an exophytic gastrointestinal stromal tumor (GIST) using a novel perforation-free suction excavation technique. A 49-year-old woman presented for further management of a gastric subepithelial tumor on the lesser curvature of the lower body, originally detected via routine upper gastrointestinal endoscopy. Abdominal computed tomography and endoscopic ultrasound showed a 4-cm extraluminally protruding mass originating from the muscularis propria layer. The patient firmly refused surgical resection owing to potential cardiac problems, and informed consent was obtained for endoscopic removal. Careful dissection and suction of the tumor was repeated until successful extraction was achieved without serosal injury. We named this procedure the suction excavation technique. The tumor’s dimensions were 3.5 cm × 2.8 cm × 2.5 cm. The tumor was positive for C-KIT and CD34 by immunohistochemical staining. The mitotic count was 6/50 high-power fields. The patient was followed for 5 years without tumor recurrence. This case demonstrated the use of endoscopic resection of an exophytic GIST using the suction excavation technique as a potential therapy without surgical resection. PMID:27340363

Feasibility Study on UAV-assisted Construction Surplus Soil Tracking Control and Management Technique

NASA Astrophysics Data System (ADS)

Jieh Haur, Chen; Kuo, Lin Sheng; Fu, Chen Ping; Li Hsu, Yeh; Da Heng, Chen

2018-01-01

Construction surplus soil tracking management has been the key management issue in Taiwan since 1991. This is mainly due to the construction surplus soils were often regarded as disposable waste and were disposed openly without any supervision, leading to environmental pollution. Even though the surplus soils were gradually being viewed as reusable resources, some unscrupulous enterprises still dump them freely for their own convenience. In order to dispose these surplus soils, site offices are required to confirm with the soil treatment plant regarding the approximate soil volume for hauling vehicle dispatch. However, the excavated soil volume will transform from bank volume to loose volume upon excavation, which may differ by a certain speculative coefficient (1.3), depending on the excavation site and geological condition. For managing and tracking the construction surplus soils, local government authorities frequently performed on-site spot check, but the lack of rapid assessment tools for soil volume estimation increased the evaluation difficulty for on-site inspectors. This study adopted unmanned aerial vehicle (UAV) in construction surplus soil tracking and rapidly acquired site photography and point cloud data, the excavated soil volume can be determined promptly after post-processing and interpretation, providing references to future surplus soil tracking management.

Middle and late Pleistocene Middle Stone Age lithic technology from Pinnacle Point 13B (Mossel Bay, Western Cape Province, South Africa).

PubMed

Thompson, Erin; Williams, Hope M; Minichillo, Tom

2010-01-01

Excavations at a complex of caves and open air sites at Pinnacle Point, Mossel Bay, Southern Africa have uncovered rich stratified assemblages of Middle Stone Age materials, including those from Pinnacle Point Cave 13B (PP13B) that comprises the first modernly excavated assemblage in southern Africa to be securely dated to the Middle Pleistocene. We report here on the complete excavated lithic artifact assemblage from PP13B. Both technological and typological analyses of the complete assemblage were performed. The assemblage-scale analysis allows for intrasite comparison as well as comparison of the PP13B assemblage with other sites from the region. No size-related pattern of change over time was observed within the PP13B assemblage, although there is significant evidence for varying strategies of lithic reduction between excavation areas within the cave. Comparison with other material from the Southern African MSA suggests that there is significant inter- and intra-site variability in the Southern African Middle Stone Age, even between portions of assemblages that are roughly contemporaneous. Copyright © 2010 Elsevier Ltd. All rights reserved.

Burials from Wadi Mudayfa'at and Wadi Abu Khasharif, Southern Jordan - Results of a Survey and Salvage Excavations

NASA Astrophysics Data System (ADS)

Salameen, Zeyad al; Falahat, Hani

This paper presents the preliminary results of a survey and excavation conducted in 2006 on small cemeteries at Wadi Mudayfa'at and Wadi Abu Khasharif, which are located c. 30 km southeast of the village of al-Hussayniah on the Desert Highway in southern Jordan. In total five graves were excavated. Preservation was excellent including human and other organic materials (hair, leather, textiles). Preliminary scientific dating points to the period between the second and fourth centuries AD. The research questions discussed are: - the date, the relationship between the cemeteries and surrounding sites, the significance of this area, the identity of the groups buried, the burial techniques and practices adopted and what influenced them and the funerary gifts included with the dead.

KSC-2011-3958

NASA Image and Video Library

2011-05-24

CAPE CANAVERAL, Fla. -- Inside the "Lunarena" at the Kennedy Space Center Visitor Complex is a remote controlled or autonomous excavator, called a lunabot. Thirty-six teams of undergraduate and graduate students from the United States, Bangladesh, Canada, Colombia and India will participate in NASA's Lunabotics Mining Competition May 26 - 28 at the agency's Kennedy Space Center in Florida. The competition is designed to engage and retain students in science, technology, engineering and mathematics (STEM). Teams will maneuver their remote controlled or autonomous excavators, called lunabots, in about 60 tons of ultra-fine simulated lunar soil, called BP-1. The competition is an Exploration Systems Mission Directorate project managed by Kennedy's Education Division. The event also provides a competitive environment that could result in innovative ideas and solutions for NASA's future excavation of the moon. Photo credit: NASA/Jack Pfaller

KSC-2011-3959

NASA Image and Video Library

2011-05-24

CAPE CANAVERAL, Fla. -- Inside the "Lunarena" at the Kennedy Space Center Visitor Complex is a remote controlled or autonomous excavator, called a lunabot. Thirty-six teams of undergraduate and graduate students from the United States, Bangladesh, Canada, Colombia and India will participate in NASA's Lunabotics Mining Competition May 26 - 28 at the agency's Kennedy Space Center in Florida. The competition is designed to engage and retain students in science, technology, engineering and mathematics (STEM). Teams will maneuver their remote controlled or autonomous excavators, called lunabots, in about 60 tons of ultra-fine simulated lunar soil, called BP-1. The competition is an Exploration Systems Mission Directorate project managed by Kennedy's Education Division. The event also provides a competitive environment that could result in innovative ideas and solutions for NASA's future excavation of the moon. Photo credit: NASA/Jack Pfaller

The Structure of Reclaiming Warehouse of Minerals at Open-Cut Mines with the Use Combined Transport

NASA Astrophysics Data System (ADS)

Ikonnikov, D. A.; Kovshov, S. V.

2017-07-01

In the article performed an analysis of ore reclaiming and overloading point characteristics at modern opencast mines. Ore reclaiming represents the most effective way of stability support of power-intensive and expensive technological dressing process, and, consequently, of maintenance of the optimal production and set-up parameters of extraction and quality of finished product. The paper proposed the construction of the warehouse describing the technology of its creation. Equipment used for the warehouse described in detail. All stages of development and operation was shown. Advantages and disadvantages of using mechanical shovel excavator and hydraulic excavator “backdigger” as a reloading and reclaiming equipment was compared. Ore reclaiming and overloading point construction at cyclical and continuous method of mining using a hydraulic excavator “backdigger” was proposed.

Proposal for a lunar tunnel-boring machine

NASA Technical Reports Server (NTRS)

Allen, Christopher S.; Cooper, David W.; Davila, David, Jr.; Mahendra, Christopher S.; Tagaras, Michael A.

1988-01-01

A need exists for obtaining a safe and habitable lunar base that is free from the hazards of radiation, temperature gradient, and micrometeorites. A device for excavating lunar material and simultaneously generating living space in the subselenian environment was studied at the conceptual level. Preliminary examinations indicate that a device using a mechanical head to shear its way through the lunar material while creating a rigid ceramic-like lining meets design constraints using existing technology. The Lunar Tunneler is totally automated and guided by a laser communication system. There exists the potential for the excavated lunar material to be used in conjunction with a surface mining process for the purpose of the extraction of oxygen and other elements. Experiments into lunar material excavation and further research into the concept of a mechanical Lunar Tunneler are suggested.

Component and System Sensitivity Considerations for Design of a Lunar ISRU Oxygen Production Plant

NASA Technical Reports Server (NTRS)

Linne, Diane L.; Gokoglu, Suleyman; Hegde, Uday G.; Balasubramaniam, Ramaswamy; Santiago-Maldonado, Edgardo

2009-01-01

Component and system sensitivities of some design parameters of ISRU system components are analyzed. The differences between terrestrial and lunar excavation are discussed, and a qualitative comparison of large and small excavators is started. The effect of excavator size on the size of the ISRU plant's regolith hoppers is presented. Optimum operating conditions of both hydrogen and carbothermal reduction reactors are explored using recently developed analytical models. Design parameters such as batch size, conversion fraction, and maximum particle size are considered for a hydrogen reduction reactor while batch size, conversion fraction, number of melt zones, and methane flow rate are considered for a carbothermal reduction reactor. For both reactor types the effect of reactor operation on system energy and regolith delivery requirements is presented.

Shape optimization of road tunnel cross-section by simulated annealing

NASA Astrophysics Data System (ADS)

Sobótka, Maciej; Pachnicz, Michał

2016-06-01

The paper concerns shape optimization of a tunnel excavation cross-section. The study incorporates optimization procedure of the simulated annealing (SA). The form of a cost function derives from the energetic optimality condition, formulated in the authors' previous papers. The utilized algorithm takes advantage of the optimization procedure already published by the authors. Unlike other approaches presented in literature, the one introduced in this paper takes into consideration a practical requirement of preserving fixed clearance gauge. Itasca Flac software is utilized in numerical examples. The optimal excavation shapes are determined for five different in situ stress ratios. This factor significantly affects the optimal topology of excavation. The resulting shapes are elongated in the direction of a principal stress greater value. Moreover, the obtained optimal shapes have smooth contours circumscribing the gauge.

Investigations of Archaeological Glass Bracelets and Perfume Bottles Excavated in Ancient Ainos (Enez) by Multiple Analytical Techniques

NASA Astrophysics Data System (ADS)

Celik, S.; Akyuz, T.; Akyuz, S.; Ozel, A. E.; Kecel-Gunduz, S.; Basaran, S.

2018-03-01

Fragments of two perfume bottles belonging to the Hellenistic and Roman periods, and five bracelets belonging to the Roman, Byzantine, and Ottoman periods, excavated in the archaeological site of Enez during the excavations in 2000, have been investigated. The samples were analyzed using micro-Raman, FTIR, and energy dispersive X-ray fluorescence techniques, in order to study the ancient technology of glass production and to determine chemical compositions of the basic components and coloring elements of the glassware. All the investigated glasses can be characterized as low-magnesia-soda-lime silicate glasses, whose colors are induced by metal ions. The melting points of the investigated glasses are estimated to be quite close to each other and around 1000°C.

Key Techniques and Risk Management for the Application of the Pile-Beam-Arch (PBA) Excavation Method: A Case Study of the Zhongjie Subway Station

PubMed Central

Guan, Yong-ping; Zhao, Wen; Li, Shen-gang; Zhang, Guo-bin

2014-01-01

The design and construction of shallow-buried tunnels in densely populated urban areas involve many challenges. The ground movements induced by tunneling effects pose potential risks to infrastructure such as surface buildings, pipelines, and roads. In this paper, a case study of the Zhongjie subway station located in Shenyang, China, is examined to investigate the key construction techniques and the influence of the Pile-Beam-Arch (PBA) excavation method on the surrounding environment. This case study discusses the primary risk factors affecting the environmental safety and summarizes the corresponding risk mitigation measures and key techniques for subway station construction using the PBA excavation method in a densely populated urban area. PMID:25221783

Detection of tunnel excavation using fiber optic reflectometry: experimental validation

NASA Astrophysics Data System (ADS)

Linker, Raphael; Klar, Assaf

2013-06-01

Cross-border smuggling tunnels enable unmonitored movement of people and goods, and pose a severe threat to homeland security. In recent years, we have been working on the development of a system based on fiber- optic Brillouin time domain reflectometry (BOTDR) for detecting tunnel excavation. In two previous SPIE publications we have reported the initial development of the system as well as its validation using small-scale experiments. This paper reports, for the first time, results of full-scale experiments and discusses the system performance. The results confirm that distributed measurement of strain profiles in fiber cables buried at shallow depth enable detection of tunnel excavation, and by proper data processing, these measurements enable precise localization of the tunnel, as well as reasonable estimation of its depth.

Test Area B-70 Final Range Environmental Assessment, Revision 1

DTIC Science & Technology

2009-06-01

the Sandhills and Open Grassland ecological associations on the Eglin Range, where it excavates a tunnel -like burrow for shelter from climatic extremes...Sciurus niger Gallberry Ilex glabra Least Shrew Cryptotis parva Gopher Apple Licania michauxii Cottontail Rabbit Sylvilagus floridanus Sand Blackberry ...within the Sandhills and Open Grassland ecological associations on Eglin, where it excavates a tunnel - like burrow for shelter from climatic extremes and

Constructing Artifical Red-Cockaded Woodpecker Cavities

Treesearch

David H. Allen

1991-01-01

A complete guide is provided for excavating red-cockaded woodpecker (Picoides borealis) cavities. A hole 4 inches wide by 10 inches high by 6 inches deep is cut from a live pine(Pinusspp.) tree with a chainsaw, and a prefabricated cavity is inserted. Cavities can be excavated in pines of any age, but the diameter of the tree at the height of insertion must be greater...

Modeling and simulating two cut-to-length harvesting systems in central Appalachian hardwoods

Treesearch

Jingxin Wang; Chris B. LeDoux; Yaoxiang Li

2003-01-01

The production rates and costs of two cut-to-length harvesting systems was simulated using a modular ground-based simulation model and stand yield data from fully stocked, second growth even aged central Appalachian hardwood forests. The two harvesters simulated were a modified John Deere 988 tracked excavator with a model RP 1600 single grip sawhead and an excavator...

Archeological and Historic Cultural Resources Inventory for a Proposed Flood Control Project at Devils Lake, Ramsey County, North Dakota.

DTIC Science & Technology

1983-10-01

Chautauqua Association signed a contract with J.H. McCulloch to secure a right-of- way for the Chautauqua Railway. McCulloch received a 30 year franchise in...excavation at Bakery of U.S. military fort Palo Duro St. Park, TX; Test excavation at historic dugout Sea Rim State Park, TX; Archaeological survey San

Not for School, but for Life: Lessons from the Historical Archaeology of the Phoenix Indian School. Office of Cultural Resource Management Report #95.

ERIC Educational Resources Information Center

Lindauer, Owen

The Phoenix Indian School, which served as a coeducational federal boarding school for American Indian students between 1891 and 1990, was partially excavated in 1995. Drawing upon written records, books, student recollections, and the school newspaper, this report summarizes what was learned from the excavation about life at the school. The first…

Overdepth Dredging and Characterization Depth Recommendations

DTIC Science & Technology

2007-06-01

bucket is hoisted to the surface and usually side dumped into a barge or sidecast to its placement site. The general clamshell dredge’s horizontal...excavation accuracies vary as a function of type of dredging equipment used (mechanical or hydraulic ) and interaction with site-specific physical...surveys. Dredge excavation accuracies vary as a function of the type of dredging equipment used (mechanical or hydraulic ) and its respective

Excavator Design Validation

NASA Technical Reports Server (NTRS)

Pholsiri, Chalongrath; English, James; Seberino, Charles; Lim, Yi-Je

2010-01-01

The Excavator Design Validation tool verifies excavator designs by automatically generating control systems and modeling their performance in an accurate simulation of their expected environment. Part of this software design includes interfacing with human operations that can be included in simulation-based studies and validation. This is essential for assessing productivity, versatility, and reliability. This software combines automatic control system generation from CAD (computer-aided design) models, rapid validation of complex mechanism designs, and detailed models of the environment including soil, dust, temperature, remote supervision, and communication latency to create a system of high value. Unique algorithms have been created for controlling and simulating complex robotic mechanisms automatically from just a CAD description. These algorithms are implemented as a commercial cross-platform C++ software toolkit that is configurable using the Extensible Markup Language (XML). The algorithms work with virtually any mobile robotic mechanisms using module descriptions that adhere to the XML standard. In addition, high-fidelity, real-time physics-based simulation algorithms have also been developed that include models of internal forces and the forces produced when a mechanism interacts with the outside world. This capability is combined with an innovative organization for simulation algorithms, new regolith simulation methods, and a unique control and study architecture to make powerful tools with the potential to transform the way NASA verifies and compares excavator designs. Energid's Actin software has been leveraged for this design validation. The architecture includes parametric and Monte Carlo studies tailored for validation of excavator designs and their control by remote human operators. It also includes the ability to interface with third-party software and human-input devices. Two types of simulation models have been adapted: high-fidelity discrete element models and fast analytical models. By using the first to establish parameters for the second, a system has been created that can be executed in real time, or faster than real time, on a desktop PC. This allows Monte Carlo simulations to be performed on a computer platform available to all researchers, and it allows human interaction to be included in a real-time simulation process. Metrics on excavator performance are established that work with the simulation architecture. Both static and dynamic metrics are included.

The 100-C-7 Remediation Project. An Overview of One of DOE's Largest Remediation Projects - 13260

DOE Office of Scientific and Technical Information (OSTI.GOV)

Post, Thomas C.; Strom, Dean; Beulow, Laura

The U.S. Department of Energy Richland Operations Office (RL), U.S. Environmental Protection Agency (EPA) and Washington Closure Hanford LLC (WCH) completed remediation of one of the largest waste sites in the U.S. Department of Energy complex. The waste site, 100-C-7, covers approximately 15 football fields and was excavated to a depth of 85 feet (groundwater). The project team removed a total of 2.3 million tons of clean and contaminated soil, concrete debris, and scrap metal. 100-C-7 lies in Hanford's 100 B/C Area, home to historic B and C Reactors. The waste site was excavated in two parts as 100-C-7 andmore » 100-C-7:1. The pair of excavations appear like pit mines. Mining engineers were hired to design their tiered sides, with safety benches every 17 feet and service ramps which allowed equipment access to the bottom of the excavations. The overall cleanup project was conducted over a span of almost 10 years. A variety of site characterization, excavation, load-out and sampling methodologies were employed at various stages of remediation. Alternative technologies were screened and evaluated during the project. A new method for cost effectively treating soils was implemented - resulting in significant cost savings. Additional opportunities for minimizing waste streams and recycling were identified and effectively implemented by the project team. During the final phase of cleanup the project team applied lessons learned throughout the entire project to address the final, remaining source of chromium contamination. The C-7 cleanup now serves as a model for remediating extensive deep zone contamination sites at Hanford. (authors)« less

Evidence for and geomorphologic consequences of a reptilian ecosystem engineer: The burrowing cascade initiated by the Gopher Tortoise

NASA Astrophysics Data System (ADS)

Kinlaw, A.; Grasmueck, M.

2012-07-01

Physical ecosystem engineers often make major, durable physical constructs that can provide living space for other species and can structure local animal communities over evolutionary time. In Florida, a medium sized chelonian, the Gopher Tortoise (Gopherus polyphemus) will excavate extensive subterranean chambers that can endure for long periods of time. The tortoise starts a 'burrowing cascade', by first excavating a larger burrow that may extend 10 m, which is then re-engineered by Florida Mice (Podomys floridanus) and other rodents that dig smaller side-burrows and pockets. This sequence is often followed by an invertebrate, the camel cricket (Ceuthophilus labibuli) which is reported to excavate even smaller chambers. Our first aim was to quantify the zoogeomorphic impact of this burrowing cascade by measuring the amount of soil excavated in a large sample of burrows in two communities. Secondly, we hypothesized that the high biodiversity reported for these structures might be related to the quasi-fractal nature of the geometry, following the work of Frontier (1987). To visualize this underground geometry, we used high-resolution 3D Ground Penetrating Radar (GPR), which provided images and insights previously unobtainable using excavations or 2D GPR. Our images verified that the active tortoise burrow had a spiraling shape, but also showed splits in the larger burrow apparently dug by tortoises. For the first time, the smaller Florida Mouse burrows were imaged, showing side loops that exit and re-renter the tortoise burrow. This study also presents new information by making the discovery of numerous remnants of past tortoise burrows underground in the sampling grid surrounding the active burrow. Our third aim was to interpret our field results with previous ecological field studies to evaluate the strength of evidence that this species ranks as an ecosystem engineer.

Excavation and aggregation as organizing factors in de novo construction by mound-building termites.

PubMed

Green, Ben; Bardunias, Paul; Turner, J Scott; Nagpal, Radhika; Werfel, Justin

2017-06-14

Termites construct complex mounds that are orders of magnitude larger than any individual and fulfil a variety of functional roles. Yet the processes through which these mounds are built, and by which the insects organize their efforts, remain poorly understood. The traditional understanding focuses on stigmergy, a form of indirect communication in which actions that change the environment provide cues that influence future work. Termite construction has long been thought to be organized via a putative 'cement pheromone': a chemical added to deposited soil that stimulates further deposition in the same area, thus creating a positive feedback loop whereby coherent structures are built up. To investigate the detailed mechanisms and behaviours through which termites self-organize the early stages of mound construction, we tracked the motion and behaviour of major workers from two Macrotermes species in experimental arenas. Rather than a construction process focused on accumulation of depositions, as models based on cement pheromone would suggest, our results indicated that the primary organizing mechanisms were based on excavation. Digging activity was focused on a small number of excavation sites, which in turn provided templates for soil deposition. This behaviour was mediated by a mechanism of aggregation, with termites being more likely to join in the work at an excavation site as the number of termites presently working at that site increased. Statistical analyses showed that this aggregation mechanism was a response to active digging, distinct from and unrelated to putative chemical cues that stimulate deposition. Agent-based simulations quantitatively supported the interpretation that the early stage of de novo construction is primarily organized by excavation and aggregation activity rather than by stigmergic deposition. © 2017 The Author(s).

Excavation and aggregation as organizing factors in de novo construction by mound-building termites

PubMed Central

Bardunias, Paul; Turner, J. Scott; Nagpal, Radhika; Werfel, Justin

2017-01-01

Termites construct complex mounds that are orders of magnitude larger than any individual and fulfil a variety of functional roles. Yet the processes through which these mounds are built, and by which the insects organize their efforts, remain poorly understood. The traditional understanding focuses on stigmergy, a form of indirect communication in which actions that change the environment provide cues that influence future work. Termite construction has long been thought to be organized via a putative ‘cement pheromone’: a chemical added to deposited soil that stimulates further deposition in the same area, thus creating a positive feedback loop whereby coherent structures are built up. To investigate the detailed mechanisms and behaviours through which termites self-organize the early stages of mound construction, we tracked the motion and behaviour of major workers from two Macrotermes species in experimental arenas. Rather than a construction process focused on accumulation of depositions, as models based on cement pheromone would suggest, our results indicated that the primary organizing mechanisms were based on excavation. Digging activity was focused on a small number of excavation sites, which in turn provided templates for soil deposition. This behaviour was mediated by a mechanism of aggregation, with termites being more likely to join in the work at an excavation site as the number of termites presently working at that site increased. Statistical analyses showed that this aggregation mechanism was a response to active digging, distinct from and unrelated to putative chemical cues that stimulate deposition. Agent-based simulations quantitatively supported the interpretation that the early stage of de novo construction is primarily organized by excavation and aggregation activity rather than by stigmergic deposition. PMID:28615497

Effect of Blast-Induced Vibration from New Railway Tunnel on Existing Adjacent Railway Tunnel in Xinjiang, China

NASA Astrophysics Data System (ADS)

Liang, Qingguo; Li, Jie; Li, Dewu; Ou, Erfeng

2013-01-01

The vibrations of existing service tunnels induced by blast-excavation of adjacent tunnels have attracted much attention from both academics and engineers during recent decades in China. The blasting vibration velocity (BVV) is the most widely used controlling index for in situ monitoring and safety assessment of existing lining structures. Although numerous in situ tests and simulations had been carried out to investigate blast-induced vibrations of existing tunnels due to excavation of new tunnels (mostly by bench excavation method), research on the overall dynamical response of existing service tunnels in terms of not only BVV but also stress/strain seemed limited for new tunnels excavated by the full-section blasting method. In this paper, the impacts of blast-induced vibrations from a new tunnel on an existing railway tunnel in Xinjiang, China were comprehensively investigated by using laboratory tests, in situ monitoring and numerical simulations. The measured data from laboratory tests and in situ monitoring were used to determine the parameters needed for numerical simulations, and were compared with the calculated results. Based on the results from in situ monitoring and numerical simulations, which were consistent with each other, the original blasting design and corresponding parameters were adjusted to reduce the maximum BVV, which proved to be effective and safe. The effect of both the static stress before blasting vibrations and the dynamic stress induced by blasting on the total stresses in the existing tunnel lining is also discussed. The methods and related results presented could be applied in projects with similar ground and distance between old and new tunnels if the new tunnel is to be excavated by the full-section blasting method.

Remediation of PCB contaminated soils in the Canadian Arctic: excavation and surface PRB technology.

PubMed

Kalinovich, Indra; Rutter, Allison; Poland, John S; Cairns, Graham; Rowe, R Kerry

2008-12-15

The site BAF-5 is located on the summit of Resolution Island, Nunavut, just southeast of Baffin Island at 61 degrees 35'N and 60 degrees 40'W. The site was part of a North American military defense system established in the 1950s that became heavily contaminated with PCBs during and subsequent, its operational years. Remediation through excavation of the PCB contaminated soil at Resolution Island began in 1999 and at its completion in 2006 approximately 5 tonnes of pure PCBs in approximately 20,000 m3 of soil were remediated. Remediation strategies were based on both quantity of soil and level of contamination in the soil. Excavation removed 96% of the PCB contaminated soil on site. In 2003, a surface funnel-and-gate permeable reactive barrier was design and constructed to treat the remaining contamination left in rock crevices and inaccessible areas of the site. Excavation had destabilized contaminated soil in the area, enabling contaminant migration through erosion and runoff pathways. The barrier was designed to maximize sedimentation through settling ponds. This bulk removal enabled the treatment of highly contaminated fines and water through a permeable gate. The increased sediment loading during excavation required both modifications to the funnel and a shift to a more permeable, granular system. Granulated activated charcoal was chosen for its ability to both act as a particle retention filter and adsorptive filter. The reduction in mass of PCB and volume of soils trapped by the funnel of the barrier indicate that soils are re-stabilizing. In 2007, nonwoven geotextiles were re-introduced back into the filtration system as fine filtering could be achieved without clogging. Monitoring sites downstream indicate that the barrier system is effective. This paper describes the field progress of PCB remediation at Resolution Island.

Combined GPR and ERT exploratory geophysical survey of the Medieval Village of Pancorbo Castle (Burgos, Spain)

NASA Astrophysics Data System (ADS)

Fernández-Álvarez, José-Paulino; Rubio-Melendi, David; Quirós Castillo, Juan Antonio; González-Quirós, Andrés; Cimadevilla-Fuente, David

2017-09-01

Ground-penetrating Radar (GPR) and Electrical Resistivity Tomography (ERT) have been fruitfully employed for archaeological purposes. An area at the Pancorbo medieval site in Burgos (Spain) has been jointly explored by GPR and ERT in the search for the buried remains of the Pancorbo medieval village. After data collection, quality control and merging, a shallow depth of interest was identified and studied in detail. 3D resistivity simulation, considering sensible geometrical structures of the targets helped discover anomalies present in the area. On the other hand, visual GPR inspection was considerably enhanced by trace energy attribute analysis which provided a plan view of the existing anomalies. Two posterior archaeological excavations have a very good correlation between the identified anomalies and the excavated remains. The survey also provides hints for the continuation of the excavation.

Evidences for the view of the importance of Hepu seaport in ancient China

NASA Astrophysics Data System (ADS)

Guan, Yongjing; Xiong, Zhaoming; Ruan, Xiangdong; Wang, Huijuan; Terrasi, Filippo

2013-01-01

Two ancient tombs considered belonging to the Han Dynasty (206 BC to AD 220), were excavated in Hepu, Guangxi Zhuang Autonomous Region, China. According to the style of cultural relics, some excavated artifacts did not come from the region. If the age of the tombs can be confirmed as belonging to the Han Dynasty, the exotic artifacts present significant evidence to suggest that that Hepu is one of the oldest seaports on China’s ancient maritime trading route. Two wood samples were sent for 14C dating at CIRCE, Italy. The results of these measurements are presented and the related chronology is discussed. Considering the previous results from a pottery workshop and an excavated sea wharf, the interpretation of Hepu as one of the oldest seaports in ancient China and the important role it played is presented.

KSC-2011-4001

NASA Image and Video Library

2011-05-25

CAPE CANAVERAL, Fla. -- University students prepare their remote controlled or autonomous excavator, called a lunabot, in a tent next to the "Lunarena" at the Kennedy Space Center Visitor Complex. Thirty-six teams of undergraduate and graduate students from the United States, Bangladesh, Canada, Colombia and India will participate in NASA's Lunabotics Mining Competition May 26 - 28 at the agency's Kennedy Space Center in Florida. The competition is designed to engage and retain students in science, technology, engineering and mathematics (STEM). Teams will maneuver their remote controlled or autonomous excavators, called lunabots, in about 60 tons of ultra-fine simulated lunar soil, called BP-1. The competition is an Exploration Systems Mission Directorate project managed by Kennedy's Education Division. The event also provides a competitive environment that could result in innovative ideas and solutions for NASA's future excavation of the moon. Photo credit: NASA/Frankie Martin

KSC-2011-4000

NASA Image and Video Library

2011-05-25

CAPE CANAVERAL, Fla. -- University students prepare their remote controlled or autonomous excavator, called a lunabot, in a tent next to the "Lunarena" at the Kennedy Space Center Visitor Complex. Thirty-six teams of undergraduate and graduate students from the United States, Bangladesh, Canada, Colombia and India will participate in NASA's Lunabotics Mining Competition May 26 - 28 at the agency's Kennedy Space Center in Florida. The competition is designed to engage and retain students in science, technology, engineering and mathematics (STEM). Teams will maneuver their remote controlled or autonomous excavators, called lunabots, in about 60 tons of ultra-fine simulated lunar soil, called BP-1. The competition is an Exploration Systems Mission Directorate project managed by Kennedy's Education Division. The event also provides a competitive environment that could result in innovative ideas and solutions for NASA's future excavation of the moon. Photo credit: NASA/Frankie Martin

KSC-2011-3960

NASA Image and Video Library

2011-05-24

University students prepare their team's remote controlled or autonomous excavator, called a lunabot, to maneuver in about 60 tons of ultra-fine simulated lunar soil, called BP-1. Thirty-six teams of undergraduate and graduate students from the United States, Bangladesh, Canada, Colombia and India will participate in NASA's Lunabotics Mining Competition May 26 - 28 at the agency's Kennedy Space Center in Florida. The competition is designed to engage and retain students in science, technology, engineering and mathematics (STEM). Teams will maneuver their remote controlled or autonomous excavators, called lunabots, in about 60 tons of ultra-fine simulated lunar soil. The competition is an Exploration Systems Mission Directorate project managed by Kennedy's Education Division. The event also provides a competitive environment that could result in innovative ideas and solutions for NASA's future excavation of the moon. Photo credit: NASA/Jack Pfaller

Evaluation of geophysical properties of the lunar regolith for the design of precursor scientific missions for the space exploration initiative

NASA Technical Reports Server (NTRS)

Morgan, Paul

1990-01-01

The following topics are addressed: (1) the frequency of encountering boulders that represent hazards to lunar operations; (2) the ease of lunar soil excavation; (3) the use of explosives in excavation operation; (4) the trafficability of the regolith; (5) problems encountered in mining (probably strip mining) of the regolith; (6) the stable angle(s) of repose in excavation of the regolith; (7) the layering to be encountered in the subsurface; (8) knowledge of the regolith site and the possibility of its general application to any site on the lunar surface; (9) the data needed to characterize a site for a lunar base; (10) the influence of regolith properties on the design of geophysical experiments from the lunar base; and (11) terrestrial analogues for the geophysical properties of the lunar regolith.

Advanced Containment System

DOEpatents

Kostelnik, Kevin M.; Kawamura, Hideki; Richardson, John G.; Noda, Masaru

2004-10-12

An advanced containment system for containing buried waste and associated leachate. A trench is dug on either side of the zone of interest containing the buried waste so as to accommodate a micro tunnel boring machine. A series of small diameter tunnels are serially excavated underneath the buried waste. The tunnels are excavated by the micro tunnel boring machine at a consistent depth and are substantially parallel to each other. As tunneling progresses, steel casing sections are connected end to end in the excavated portion of the tunnel so that a steel tube is formed. Each casing section has complementary interlocking structure running its length that interlocks with complementary interlocking structure on the adjacent casing section. Thus, once the first tube is emplaced, placement of subsequent tubes is facilitated by the complementary interlocking structure on the adjacent, previously placed, casing sections.

Advanced Containment System

DOEpatents

Kostelnik, Kevin M.; Kawamura, Hideki; Richardson, John G.; Noda, Masaru

2005-05-24

An advanced containment system for containing buried waste and associated leachate. A trench is dug on either side of the zone of interest containing the buried waste so as to accommodate a micro tunnel boring machine. A series of small diameter tunnels are serially excavated underneath the buried waste. The tunnels are excavated by the micro tunnel boring machine at a consistent depth and are substantially parallel to each other. As tunneling progresses, steel casing sections are connected end to end in the excavated portion of the tunnel so that a steel tube is formed. Each casing section has complementary interlocking structure running its length that interlocks with complementary interlocking structure on the adjacent casing section. Thus, once the first tube is emplaced, placement of subsequent tubes is facilitated by the complementary interlocking structure on the adjacent, previously placed, casing sections.

Inclusion of inhomogeneous deformation and strength characteristics in the problem on zonal disintegration of rocks

NASA Astrophysics Data System (ADS)

Chanyshev, AI; Belousova, OE

2018-03-01

The authors determine stress and deformation in a heterogeneous rock mass at the preset displacement and Cauchy stress vector at the boundary of an underground excavation. The influence of coordinates on Young’s modulus, shear modulus and ultimate strength is shown. It is found that regions of tension and compression alternate at the excavation boundary—i.e. zonal rock disintegration phenomenon is observed.

27. EXCAVATION OF EAST (FRONT) BASEMENT WELL AND DRAINAGE SYSTEM, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

27. EXCAVATION OF EAST (FRONT) BASEMENT WELL AND DRAINAGE SYSTEM, WITH ARCHED ENTRY INTO BASEMENT UNDER FRONT ENTRY IN BACKGROUND, LOOKING NORTH (NOTE GALLETING IN BRICK FOUNDATION) BUT CLOSER RANGE SHOWING BRICK STRUCTURE WHICH CARRIED WATER FROM THE GUTTER DRAIN PIPE INTO THE BRICK DRAIN ALONG THE GROUND AND AWAY FROM THE FOUNDATION OF THE HOUSE - Belair, Tulip Grove Drive, Belair-at-Bowie, Bowie, Prince George's County, MD

Identification and Evaluation of Underground Obstacle Sensor Embodiments for Their Applicability to the Combat Engineers’ Rapid Excavation Mission(s),

DTIC Science & Technology

1980-01-01

November 1976. 11. Ohio State University, Electroscience Laboratory, Electromagnetic Pulse Sounding for Geological Surveying with Application in Rock...Peters, L. and Moffatt, D. L., Electromagnetic Pulse Sounding for Geological Surveying with Application in Rock Mechanics and Rapid Excavation... Electromagnetic Pulse Sounding for Geolog- ical Surveying with Application in Rock Mechanics and Rapid Excava- tion Program, Ohio State University, Report

Hydraulic Excavation System. Phase 2

DTIC Science & Technology

1988-09-01

excavation techniques. Hydraulic fracturing has been particulary attractive in past work. The tensile strength of most rock is less than 20 MPa, which...Fairhurst, C. (1970) "In-situ Stress Determination at Great Depth by Means of Hydraulic Fracturing ," Proceedings of the 11th Symposium on Rock...Technique for Controlled Small-scale Hydraulic Fracturing ," First International Symposium on Rock Fragmentation bY Blasting, Vol. 3, A. Rustan and R

Lunar Excavator Preliminary Test Video

NASA Technical Reports Server (NTRS)

2004-01-01

This video shows a preliminary test of the boom and bucket wheel assembly of the lunar excavator prototype developed by the Center for Commercial Applications of Combustion at the Colorado School of Mines in Golden. According to Michael Duke, director for the center, the wheel on the end of the boom can dig up 45.36 kilograms (100 pounds) of dirt each hour which is several times the weight of the entire device.

Using Frozen Barriers for Containment of Contaminants

DTIC Science & Technology

2017-09-21

barriers are constructed of grout slurry and plastic or steel sheet pilings. Circumferential barriers can be used to completely enclose a source of...2.1.1 Slurry walls A soil-bentonite slurry trench cutoff wall (slurry wall) is excavated and backfilled with grout, cement , or soil-bentonite...installation requires a mixing area, and there is a substantial amount of excavation and the need to dispose of spoil. The advantages of cement -based

Lunar Regolith Excavation Student Competition Design

NASA Technical Reports Server (NTRS)

Nething, Julia

2009-01-01

The Surface Systems team is working to learn about lunar regolith and how we can use it as a source of air, water, and fuel for spacecrafts. However, excavation of this valuable regolith is difficult because the robot has to conform to many specifications (mass limit, efficiency level, etc.). NASA has therefore decided to include college students and companies in the search to create the best robot by making it into a competition.

Microbiological Evaluation of Ozone on Dentinal Lesions in Young Permanent Molars using the Stepwise Excavation.

PubMed

Safwat, Osama; Elkateb, Mona; Dowidar, Karin; Salam, Hala Abdel; El Meligy, Omar

To assess the microbial effect of ozone gas on dentinal lesions in young permanent molars using the stepwise excavation. An experimental, controlled clinical trial was performed. The sample included 80 immature first permanent molars, showing deep occlusal carious cavities that were indicated for stepwise excavation. Following first step of dentin excavation, the sample was divided into test (ozone gas) and control (calcium hydroxide (Ca(OH) 2 ) base material) groups. One half of the cases in each group were evaluated for microbiological changes after 6 months, and the other half after 12 months. Mutans streptococci (MS), Lactobacilli, and Candida counts were significantly reduced immediately after ozone application in the test group (P ≤0.05). At the final assessment period, MS and Lactobacilli were significantly reduced in the test group (P ≤0.05). Meanwhile, the Candida counts were significantly reduced only in the test group of the 6 and 12 month-cases (P ≤0.05). Regarding the control group, the significant reduction in microbial count was observed with MS after 6 and 12 months (P ≤0.05). No significant differences were observed between test and control groups at different evaluation periods (P >0.05). Ozone gas had a significant antimicrobial effect in deep class I carious lesions.

[Anatomical names of fossae and foveae in skeleton].

PubMed

Shikano, S; Yamashita, Y

1999-09-01

Latin anatomical names of Fossae and Foveae in the skeleton were analyzed and compared with Japanese anatomical names for better understanding of the structures of the human body and for possible revision in the future. The conclusions were as follows: 1. In general, round excavations were called Foveae (singular : Fovea), and nonround excavations were called Fossae (singular : Fossa). Some shallow excavations for articulation and some shallow excavations with the names which indicate their contents were called Foveae even though they were not round. 2. Each name of Fossae contained the word which indicates form, location or content of Fossa, the bone (or osseous structure) which articulates with Fossa, or the muscle which is attached to Fossa. 3. Each name of Foveae contained the word which indicates location, content or articulation of Fovea, the bone (or osseous structure) which articulates with Fovea, or the muscle (or muscular trochlea) which is attached to Fovea. 4. The Japanese name which corresponds to Fossa canina should be changed from Kenshi (canine tooth) = ka (fossa) to Kenshikin (canine muscle) = ka or Koukakukyokin (levator anguli oris muscle) = ka. 5. The Japanese name which corresponds to Fossa pterygopalatina should be changed from Yoku (wing) = kougai (palate) = ka (fossa) to Yokutotsu (pterygoid process) = kougaikotsu (palatine bone) = ka.

Analysis of pottery from the Palatine Hills of Rome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Landsberger, S.; Wisseman, S.; Desena, E.

1994-12-31

During the past several summers the Soprintendenza Archeologica di Roma and the American Academy in Rome have carried out collaborative excavations on the late Roman complex located on the northeastern slope of the Palatine Hill. The late Roman complex is situated on the lower slopes of the area commonly known as Vigna Barberini, after its 17th century owners. Because this area, as well as most of the east slope of the Palatine, has never been systematically explored, it remains from an archaeological point of view essentially unknown. The overall aim of the excavations is to investigate layout, function, and occupationalmore » history of a mid-to-late imperial building complex located just southwest of the Arch of Constatine. Part of this international project is the chemical characterization of Roman fineware pottery from archaeological excavations on the site of the imperial palaces. Excavation has yielded more than 8 t of Late Roman and Early Medieval pottery (circa 3rd to 10th centuries A.D.). Many classes of pottery have already been classified by their provenance based on distribution patterns, but others require chemical characterization to separate similar clays. To that end routine neutron activation analysis (NAA) methods have been used to analyze {approximately}200 pieces of pottery.« less

Hydrogeological conceptual model determined from baseline and construction phase groundwater pressure and surface tilt-meter data at the Mizunami underground research laboratory, Japan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takeuchi, Shinji; Takeuchi, Ryuji; Salden, Walter

2007-07-01

A hydrogeological conceptual model has been developed based on pressure responses observed at multilevel pressure monitoring zones in seven boreholes and surface tilt data in and around the Mizunami Underground Research Laboratory site. Pressure changes caused by some earthquakes, cross-hole hydraulic testing, and shaft excavation activities are considered. Surface tilt has been measured from the half way of the shaft excavation phase. The shaft excavation has been commenced from July 2003 with two shafts (Main shaft and Ventilation shaft). By the end of October 2005, discharging of water in the shafts has been halted at the depths of 172 mmore » and 191 m respectively to allow modifications to be made to the water treatment facility due to an excess of F and B concentration in the water. This results in the recovery of the groundwater levels and filling of the underground workings. Beginning in February 2006 pumping has been resumed and the underground workings have been re-occupied. Continuous groundwater pressure and surface tilt measurements with some numerical analysis during the shaft excavation phase show the existence of the flow barrier fault predicted from the surface-based investigation phase and hydraulic parameter around the shafts. (authors)« less

Floodplain Assessment for the Middle Los Alamos Canyon Aggregate Area Investigations in Technical Area 02 at Los Alamos National Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hathcock, Charles Dean

The proposed action being assessed in this document occurs in TA-02 in the bottom of Los Alamos Canyon. The DOE proposes to conduct soil sampling at AOC 02-011 (d), AOC 02- 011(a)(ii), and SWMU 02-005, and excavate soils in AOC 02-011(a)(ii) as part of a corrective actions effort. Additional shallow surface soil samples (soil grab samples) will be collected throughout the TA-02 area, including within the floodplain, to perform ecotoxicology studies (Figures 1 and 2). The excavation boundaries in AOC 02-011(a)(ii) are slightly within the delineated 100-year floodplain. The project will use a variety of techniques for soil sampling andmore » remediation efforts to include hand/digging, standard hand auger/sampling, excavation using machinery such as backhoe and front end loader and small drill rig. Heavy equipment will traverse the floodplain and spoils piles will be staged in the floodplain within developed or previously disturbed areas (e.g., existing paved roads and parking areas). The project will utilize and maintain appropriate best management practices (BMPs) to contain excavated materials, and all pollutants, including oil from machinery/vehicles. The project will stabilize disturbed areas as appropriate at the end of the project.« less

Archaeological Geophysics, Excavation, and Ethnographic Approaches Toward a Deeper Understanding of an Eighteenth Century Wichita Site

NASA Astrophysics Data System (ADS)

Carlock, Michael Don

This research exemplifies a multidirectional approach to an archaeological interpretation of an eighteenth century Wichita village and fortification located on the Red River bordering Oklahoma and Texas. A battle that is believed to have occurred at the Longest site (34JF1) in 1759 between Spanish colonials and a confederation of Native Americans led to several Spanish primary documents describing the people that lived there, the fortification and surrounding village, and of course the battle itself. Investigation of the Longest site (34JF1) in Oklahoma presents a remarkable opportunity to combine extensive historical research, archaeological prospecting using geophysics, and traditional excavation techniques in order to gain a more complete understanding of this important archaeological site. The fortification at the Longest site, as well as possible associated structures and cultural features, were relocated using magnetometry, ground-penetrating radar, and electrical resistivity methods. Then, previously translated historical documents provided valuable insights in the interpretation of the geophysical data. Finally, archaeological excavation permitted validation of the interpretations and identification of features described in the historical accounts. As interpreted in the geophysical data and excavations, the construction of the fortification and associated interior subterranean rooms suggests that it is indeed the fortification involved in the altercation between the Taovayas and the Spanish in 1759.

The assessment of environmentally sensitive forest road construction in Calabrian pine forest areas of Turkey.

PubMed

Tunay, Metin

2006-07-01

Forest road construction by bulldozers in Calabrian Pine (Pinus brutia Ten.) forests on mountainous terrain of Turkey causes considerable damage to the environment and the forest standing alongside the road. This situation obliges a study of environmentally sound road construction in Turkey. This study was carried out in 4 sample sites of Antalya Forest Directorate in steep (34-50% gradient) and very steep terrain (51-70% gradient) conditions with bulldozer and excavator machine and direct damages to forest during road construction was determined, including forest area losses and damages to downhill trees in mountainous areas. It was determined that in steep terrain when excavators were used, less forest area (22.16%) was destroyed compared to bulldozers and 26.54% less area in very steep terrain. The proportion of damage on trees where bulldozer worked was nearly twofold higher than excavator was used. The results of this research show that the environmentally sensitive techniques applied for the road construction projects are considerably superior to the traditional use of bulldozers on steep slopes. The environmentally sound forest road construction by use of excavator must be considered an appropriate and reliable solution for mountainous terrain where areas of sensitive forest ecosystems are to be opened up.

MARSAME Radiological Release Report for Archaeological Artifacts Excavated from Area L

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruedig, Elizabeth; Whicker, Jeffrey Jay; Gillis, Jessica Mcdonnel

In 1991 Los Alamos National Laboratory’s (LANL’s) cultural resources team excavated archaeological site LA 4618 located at Technical Area 54, within Material Disposal Area L (MDA L). MDA L received non-radioactive chemical waste from the early 1960s until 1985. Further development of the MDA required excavation of several cultural sites under National Historic Preservation Act requirements; artifacts from these sites have been subsequently stored at LANL. The LANL cultural resources group would now like to release these artifacts to the Museum of Indian Arts and Culture in Santa Fe for curation. The history of disposal at Area L suggests thatmore » the artifact pool is unlikely to be chemically contaminated and LANL staff washed each artifact at least once following excavation. Thus, it is unlikely that the artifacts present a chemical hazard. LANL’s Environmental Stewardship group (EPC-ES) has evaluated the radiological survey results for the Area L artifact pool and found that the items described in this report meet the criteria for unrestricted radiological release under Department of Energy (DOE) Order 458.1 Radiation Protection of the Public and the Environment and are candidates for release without restriction from LANL control. This conclusion is based on the known history of MDA L and on radiation survey data.« less

Multirobot Lunar Excavation and ISRU Using Artificial-Neural-Tissue Controllers

NASA Astrophysics Data System (ADS)

Thangavelautham, Jekanthan; Smith, Alexander; Abu El Samid, Nader; Ho, Alexander; Boucher, Dale; Richard, Jim; D'Eleuterio, Gabriele M. T.

2008-01-01

Automation of site preparation and resource utilization on the Moon with teams of autonomous robots holds considerable promise for establishing a lunar base. Such multirobot autonomous systems would require limited human support infrastructure, complement necessary manned operations and reduce overall mission risk. We present an Artificial Neural Tissue (ANT) architecture as a control system for autonomous multirobot excavation tasks. An ANT approach requires much less human supervision and pre-programmed human expertise than previous techniques. Only a single global fitness function and a set of allowable basis behaviors need be specified. An evolutionary (Darwinian) selection process is used to `breed' controllers for the task at hand in simulation and the fittest controllers are transferred onto hardware for further validation and testing. ANT facilitates `machine creativity', with the emergence of novel functionality through a process of self-organized task decomposition of mission goals. ANT based controllers are shown to exhibit self-organization, employ stigmergy (communication mediated through the environment) and make use of templates (unlabeled environmental cues). With lunar in-situ resource utilization (ISRU) efforts in mind, ANT controllers have been tested on a multirobot excavation task in which teams of robots with no explicit supervision can successfully avoid obstacles, interpret excavation blueprints, perform layered digging, avoid burying or trapping other robots and clear/maintain digging routes.

DEM modeling of failure mechanisms induced by excavations on the Moon

NASA Astrophysics Data System (ADS)

jiang, mingjing; shen, zhifu; Utili, Stefano

2013-04-01

2D Discrete Element Method (DEM) analyses were performed for excavations supported by retaining walls in lunar environment. The lunar terrain is made of a layer of sand (regolith) which differs from terrestrial sands for two main features: the presence of adhesive attractive forces due to van der Waals interactions and grains being very irregular in shape leading to high interlocking. A simplified contact model based on linear elasticity and perfect plasticity was employed. The contact model includes a moment - relative rotation law to account for high interlocking among grains and a normal adhesion law to account for the van der Waals interactions. Analyses of the excavations were run under both lunar and terrestrial environments. Under lunar environment, gravity is approximately one sixth than the value on Earth and adhesion forces between grains of lunar regolith due to van der Waals interactions are not negligible. From the DEM simulations it emerged that van der Waals interactions may significantly increase the bending moment and deflection of the retaining wall, and the ground displacements. Hence this study indicates that an unsafe estimate of the wall response to an excavation on the Moon would be obtained from physical experiments performed in a terrestrial environment, i.e., considering the effect of gravity but neglecting the van der Waals interactions.

Improved Concrete Cutting and Excavation Capabilities for Crater Repair, Phase 1

DTIC Science & Technology

2014-04-01

manageable pieces, it is not recommended for the ADR process because of the requirement for additional supporting equipment - the air compressor ... Air Force Civil Engineer Center Tyndall Air Force Base, FL 32403-5319 ERDC/GSL TR-14-8 ii Abstract The US Army Engineer Research and...Development Center was tasked by the US Air Force Civil Engineer Center to improve the saw cutting and excavation production rates of crater repairs in thick

Remediating Contaminant Plumes in Groundwater with Shallow Excavations Containing Coarse Reactive Media.

PubMed

Hudak, Paul F

2018-02-01

A groundwater flow and mass transport model tested the capability of shallow excavations filled with coarse, reactive media to remediate a hypothetical unconfined aquifer with a maximum saturated thickness of 5 m. Modeled as contaminant sinks, the rectangular excavations were 10 m downgradient of an initial contaminant plume originating from a source at the top of the aquifer. The initial plume was approximately 259 m long, 23 m wide, and 5 m thick, with a downgradient tip located approximately 100 m upgradient of the site boundary. The smallest trench capable of preventing offsite migration was 11 m long (measured perpendicular to groundwater flow), 4 m wide (measured parallel to groundwater flow), and 3 m deep. Results of this study suggest that shallow trenches filled with coarse filter media that partially penetrate unconfined aquifers may be a viable alternative for remediating contaminated groundwater at some sites.

KSC-2011-4145

NASA Image and Video Library

2011-05-27

CAPE CANAVERAL, Fla. -- Inside the "Lunarena" at the Kennedy Space Center Visitor Complex in Florida, university students maneuver their remote controlled or autonomous excavators, called lunabots, in a "sand box" of ultra-fine simulated lunar soil during NASA's second annual Lunabotics Mining Competition. Thirty-six teams of undergraduate and graduate students from the United States, Bangladesh, Canada, Colombia and India will participate in NASA's Lunabotics Mining Competition May 26 - 28 at the agency's Kennedy Space Center in Florida. The competition is designed to engage and retain students in science, technology, engineering and mathematics (STEM). Teams will maneuver their remote controlled or autonomous excavators, called lunabots, in about 60 tons of ultra-fine simulated lunar soil, called BP-1. The competition is an Exploration Systems Mission Directorate project managed by Kennedy's Education Division. The event also provides a competitive environment that could result in innovative ideas and solutions for NASA's future excavation of the moon. Photo credit: NASA/Jack Pfaller

KSC-2011-4157

NASA Image and Video Library

2011-05-28

CAPE CANAVERAL, Fla. -- Inside the "Lunarena" at the Kennedy Space Center Visitor Complex in Florida, university students maneuver their remote controlled or autonomous excavators, called lunabots, in a "sand box" of ultra-fine simulated lunar soil during NASA's second annual Lunabotics Mining Competition. Thirty-six teams of undergraduate and graduate students from the United States, Bangladesh, Canada, Colombia and India will participate in NASA's Lunabotics Mining Competition May 26 - 28 at the agency's Kennedy Space Center in Florida. The competition is designed to engage and retain students in science, technology, engineering and mathematics (STEM). Teams will maneuver their remote controlled or autonomous excavators, called lunabots, in about 60 tons of ultra-fine simulated lunar soil, called BP-1. The competition is an Exploration Systems Mission Directorate project managed by Kennedy's Education Division. The event also provides a competitive environment that could result in innovative ideas and solutions for NASA's future excavation of the moon. Photo credit: NASA/Jack Pfaller

KSC-2011-4161

NASA Image and Video Library

2011-05-28

CAPE CANAVERAL, Fla. -- Inside the "Lunarena" at the Kennedy Space Center Visitor Complex in Florida, university students give their "thumbs up" after maneuvering their remote controlled or autonomous excavators, called lunabots, in a "sand box" of ultra-fine simulated lunar soil during NASA's second annual Lunabotics Mining Competition. Thirty-six teams of undergraduate and graduate students from the United States, Bangladesh, Canada, Colombia and India will participate in NASA's Lunabotics Mining Competition May 26 - 28 at the agency's Kennedy Space Center in Florida. The competition is designed to engage and retain students in science, technology, engineering and mathematics (STEM). Teams will maneuver their remote controlled or autonomous excavators, called lunabots, in about 60 tons of ultra-fine simulated lunar soil, called BP-1. The competition is an Exploration Systems Mission Directorate project managed by Kennedy's Education Division. The event also provides a competitive environment that could result in innovative ideas and solutions for NASA's future excavation of the moon. Photo credit: NASA/Jack Pfaller

KSC-2011-4150

NASA Image and Video Library

2011-05-27

CAPE CANAVERAL, Fla. -- University students monitor their team's remote controlled or autonomous excavator, called a lunabot, as it is maneuvered in a "sand box" of ultra-fine simulated lunar soil during NASA's second annual Lunabotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. Thirty-six teams of undergraduate and graduate students from the United States, Bangladesh, Canada, Colombia and India will participate in NASA's Lunabotics Mining Competition May 26 - 28 at the agency's Kennedy Space Center in Florida. The competition is designed to engage and retain students in science, technology, engineering and mathematics (STEM). Teams will maneuver their remote controlled or autonomous excavators, called lunabots, in about 60 tons of ultra-fine simulated lunar soil, called BP-1. The competition is an Exploration Systems Mission Directorate project managed by Kennedy's Education Division. The event also provides a competitive environment that could result in innovative ideas and solutions for NASA's future excavation of the moon. Photo credit: NASA/Jack Pfaller

KSC-2011-4018

NASA Image and Video Library

2011-05-26

CAPE CANAVERAL, Fla. -- Inside the "Lunarena" at the Kennedy Space Center Visitor in Florida, university students maneuver their remote controlled or autonomous excavators, called lunabots, in a "sand box" of ultra-fine simulated lunar soil during NASA's second annual Lunabotics Mining Competition. Thirty-six teams of undergraduate and graduate students from the United States, Bangladesh, Canada, Colombia and India will participate in NASA's Lunabotics Mining Competition May 26 - 28 at the agency's Kennedy Space Center in Florida. The competition is designed to engage and retain students in science, technology, engineering and mathematics (STEM). Teams will maneuver their remote controlled or autonomous excavators, called lunabots, in about 60 tons of ultra-fine simulated lunar soil, called BP-1. The competition is an Exploration Systems Mission Directorate project managed by Kennedy's Education Division. The event also provides a competitive environment that could result in innovative ideas and solutions for NASA's future excavation of the moon. Photo credit: NASA/Jim Grossmann

KSC-2011-4149

NASA Image and Video Library

2011-05-27

CAPE CANAVERAL, Fla. -- University students monitor their team's remote controlled or autonomous excavator, called a lunabot, as it is maneuvered in a "sand box" of ultra-fine simulated lunar soil during NASA's second annual Lunabotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. Thirty-six teams of undergraduate and graduate students from the United States, Bangladesh, Canada, Colombia and India will participate in NASA's Lunabotics Mining Competition May 26 - 28 at the agency's Kennedy Space Center in Florida. The competition is designed to engage and retain students in science, technology, engineering and mathematics (STEM). Teams will maneuver their remote controlled or autonomous excavators, called lunabots, in about 60 tons of ultra-fine simulated lunar soil, called BP-1. The competition is an Exploration Systems Mission Directorate project managed by Kennedy's Education Division. The event also provides a competitive environment that could result in innovative ideas and solutions for NASA's future excavation of the moon. Photo credit: NASA/Jack Pfaller

KSC-2011-4162

NASA Image and Video Library

2011-05-28

CAPE CANAVERAL, Fla. -- University students monitor their team's remote controlled or autonomous excavator, called a lunabot, as it is maneuvered in a "sand box" of ultra-fine simulated lunar soil during NASA's second annual Lunabotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. Thirty-six teams of undergraduate and graduate students from the United States, Bangladesh, Canada, Colombia and India will participate in NASA's Lunabotics Mining Competition May 26 - 28 at the agency's Kennedy Space Center in Florida. The competition is designed to engage and retain students in science, technology, engineering and mathematics (STEM). Teams will maneuver their remote controlled or autonomous excavators, called lunabots, in about 60 tons of ultra-fine simulated lunar soil, called BP-1. The competition is an Exploration Systems Mission Directorate project managed by Kennedy's Education Division. The event also provides a competitive environment that could result in innovative ideas and solutions for NASA's future excavation of the moon. Photo credit: NASA/Jack Pfaller

KSC-2011-4019

NASA Image and Video Library

2011-05-26

CAPE CANAVERAL, Fla. -- University students monitor their team's remote controlled or autonomous excavator, called a lunabot, as it is maneuvered in a "sand box" of ultra-fine simulated lunar soil during NASA's second annual Lunabotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. Thirty-six teams of undergraduate and graduate students from the United States, Bangladesh, Canada, Colombia and India will participate in NASA's Lunabotics Mining Competition May 26 - 28 at the agency's Kennedy Space Center in Florida. The competition is designed to engage and retain students in science, technology, engineering and mathematics (STEM). Teams will maneuver their remote controlled or autonomous excavators, called lunabots, in about 60 tons of ultra-fine simulated lunar soil, called BP-1. The competition is an Exploration Systems Mission Directorate project managed by Kennedy's Education Division. The event also provides a competitive environment that could result in innovative ideas and solutions for NASA's future excavation of the moon. Photo credit: NASA/Jim Grossmann

Excavating silences and tensions of agency|passivity in science education reform

NASA Astrophysics Data System (ADS)

Rivera Maulucci, Maria S.

2010-12-01

I reflect on studies by Rodriguez and Carlone, Haun-Frank, and Kimmel to emphasize the ways in which they excavate silences in the science education literature related to linguistic and cultural diversity and situating the problem of reform in teachers rather than contextual factors, such as traditional schooling discourses and forces that serve to marginalize science. I propose that the current push for top-down reform and accountability diminishes opportunities for receptivity, learning with and from students in order to transform teachers' practices and promote equity in science education. I discuss tensions of agency and passivity in science education reform and argue that attention to authentic caring constitutes another silence in the science education literature. I conclude that the current policy context positions teachers and science education researchers as tempered radicals struggling against opp(reg)ressive reforms and that there is a need for more studies to excavate these and other silences.

The excavation stage of basin formation - A qualitative model

NASA Technical Reports Server (NTRS)

Croft, S. K.

1981-01-01

One of the most complex problems in planetary geology and geophysics is the determination of the nature of the impact cratering processes at scales of tens to thousands of kilometers that produce the complex morphological structures of multiring basins. The cratering process is frequently considered to be divided into three stages, including a short high-pressure stage of initial contact between the projectile and the planetary crust, a longer excavation or cratering flow stage culminating in the formation of a transient crater, and a still longer modification stage during which the transient crater is modified into the observed final geologic form. The transient crater may be considered as the initial boundary condition of the modification stage. In the present investigation, the nature of the transient crater is indicated by the cratering flow field determined from numerical simulations of the excavation stage. Attention is given to empirical and theoretical scaling.

KSC-2011-4144

NASA Image and Video Library

2011-05-27

CAPE CANAVERAL, Fla. -- Inside the "Lunarena" at the Kennedy Space Center Visitor Complex in Florida, university students maneuver their remote controlled or autonomous excavators, called lunabots, in a "sand box" of ultra-fine simulated lunar soil during NASA's second annual Lunabotics Mining Competition. Thirty-six teams of undergraduate and graduate students from the United States, Bangladesh, Canada, Colombia and India will participate in NASA's Lunabotics Mining Competition May 26 - 28 at the agency's Kennedy Space Center in Florida. The competition is designed to engage and retain students in science, technology, engineering and mathematics (STEM). Teams will maneuver their remote controlled or autonomous excavators, called lunabots, in about 60 tons of ultra-fine simulated lunar soil, called BP-1. The competition is an Exploration Systems Mission Directorate project managed by Kennedy's Education Division. The event also provides a competitive environment that could result in innovative ideas and solutions for NASA's future excavation of the moon. Photo credit: NASA/Jack Pfaller

KSC-2011-4017

NASA Image and Video Library

2011-05-26

CAPE CANAVERAL, Fla. -- Inside the "Lunarena" at the Kennedy Space Center Visitor in Florida, university students maneuver their remote controlled or autonomous excavators, called lunabots, in a "sand box" of ultra-fine simulated lunar soil during NASA's second annual Lunabotics Mining Competition. Thirty-six teams of undergraduate and graduate students from the United States, Bangladesh, Canada, Colombia and India will participate in NASA's Lunabotics Mining Competition May 26 - 28 at the agency's Kennedy Space Center in Florida. The competition is designed to engage and retain students in science, technology, engineering and mathematics (STEM). Teams will maneuver their remote controlled or autonomous excavators, called lunabots, in about 60 tons of ultra-fine simulated lunar soil, called BP-1. The competition is an Exploration Systems Mission Directorate project managed by Kennedy's Education Division. The event also provides a competitive environment that could result in innovative ideas and solutions for NASA's future excavation of the moon. Photo credit: NASA/Jim Grossmann

Effects of tunneling on groundwater flow and swelling of clay-sulfate rocks

NASA Astrophysics Data System (ADS)

Butscher, Christoph; Einstein, Herbert H.; Huggenberger, Peter

2011-11-01

Swelling of clay-sulfate rocks is a major threat in tunneling. It is triggered by the transformation of the sulfate mineral anhydrite into gypsum as a result of water inflow in anhydrite-containing layers after tunnel excavation. The present study investigates the hydraulic effects of tunneling on groundwater flow and analyzes how hydraulic changes caused by excavation lead to water inflow into anhydrite-containing layers in the tunnel area. Numerical groundwater models are used to conduct scenario simulations that allow one to relate hydrogeological conditions to rock swelling. The influence of the topographic setting, the excavation-damaged zone around the tunnel, the sealing effect of the tunnel liner, and the geological configuration are analyzed separately. The analysis is performed for synthetic situations and is complemented by a case study from a tunnel in Switzerland. The results illustrate the importance of geological and hydraulic information when assessing the risk of swelling at an actual site.

Examining the relation between rock mass cuttability index and rock drilling properties

NASA Astrophysics Data System (ADS)

Yetkin, Mustafa E.; Özfırat, M. Kemal; Yenice, Hayati; Şimşir, Ferhan; Kahraman, Bayram

2016-12-01

Drilling rate is a substantial index value in drilling and excavation operations at mining. It is not only a help in determining physical and mechanical features of rocks, but also delivers strong estimations about instantaneous cutting rates. By this way, work durations to be finished on time, proper machine/equipment selection and efficient excavation works can be achieved. In this study, physical and mechanical properties of surrounding rocks and ore zones are determined by investigations carried out on specimens taken from an underground ore mine. Later, relationships among rock mass classifications, drillability rates, cuttability, and abrasivity have been investigated using multi regression analysis. As a result, equations having high regression rates have been found out among instantaneous cutting rates and geomechanical properties of rocks. Moreover, excavation machine selection for the study area has been made at the best possible interval.

Excavating and loading equipment for peat mining

NASA Astrophysics Data System (ADS)

Mikhailov, A. V.; Zhigulskaya, A. I.; Yakonovskaya, T. B.

2017-10-01

Recently, the issues of sustainable development of Russian regions, related to ensuring energy security, are more urgent than ever. To achieve sustainable development, an integrated approach to the use of local natural resources is needed. Practically in all north regions of the Russian Federation, peat as a local natural resource is widespread, which has a practical application in the area of housing services. The paper presents the evaluation of technologies for open-pit peat mining, as well as analysis of technological equipment for peat production. Special attention is paid to a question of peat materials excavating and loading. The problem of equipment selection in a peat surface mine is complex. Many features, restrictions and criteria need to be considered. Use of low and ultra-low ground pressure excavators and low ground pressure front-end loaders with full-range tires to provide the necessary floatation in the peat bog environment is offered.

Foundation Heat Exchanger Final Report: Demonstration, Measured Performance, and Validated Model and Design Tool

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hughes, Patrick; Im, Piljae

2012-04-01

Geothermal heat pumps, sometimes called ground-source heat pumps (GSHPs), have been proven capable of significantly reducing energy use and peak demand in buildings. Conventional equipment for controlling the temperature and humidity of a building, or supplying hot water and fresh outdoor air, must exchange energy (or heat) with the building's outdoor environment. Equipment using the ground as a heat source and heat sink consumes less non-renewable energy (electricity and fossil fuels) because the earth is cooler than outdoor air in summer and warmer in winter. The most important barrier to rapid growth of the GSHP industry is high first costmore » of GSHP systems to consumers. The most common GSHP system utilizes a closed-loop ground heat exchanger. This type of GSHP system can be used almost anywhere. There is reason to believe that reducing the cost of closed-loop systems is the strategy that would achieve the greatest energy savings with GSHP technology. The cost premium of closed-loop GSHP systems over conventional space conditioning and water heating systems is primarily associated with drilling boreholes or excavating trenches, installing vertical or horizontal ground heat exchangers, and backfilling the excavations. This project investigates reducing the cost of horizontal closed-loop ground heat exchangers by installing them in the construction excavations, augmented when necessary with additional trenches. This approach applies only to new construction of residential and light commercial buildings or additions to such buildings. In the business-as-usual scenario, construction excavations are not used for the horizontal ground heat exchanger (HGHX); instead the HGHX is installed entirely in trenches dug specifically for that purpose. The potential cost savings comes from using the construction excavations for the installation of ground heat exchangers, thereby minimizing the need and expense of digging additional trenches. The term foundation heat exchanger (FHX) has been coined to refer exclusively to ground heat exchangers installed in the overcut around the basement walls. The primary technical challenge undertaken by this project was the development and validation of energy performance models and design tools for FHX. In terms of performance modeling and design, ground heat exchangers in other construction excavations (e.g., utility trenches) are no different from conventional HGHX, and models and design tools for HGHX already exist. This project successfully developed and validated energy performance models and design tools so that FHX or hybrid FHX/HGHX systems can be engineered with confidence, enabling this technology to be applied in residential and light commercial buildings. The validated energy performance model also addresses and solves another problem, the longstanding inadequacy in the way ground-building thermal interaction is represented in building energy models, whether or not there is a ground heat exchanger nearby. Two side-by-side, three-level, unoccupied research houses with walkout basements, identical 3,700 ft{sup 2} floor plans, and hybrid FHX/HGHX systems were constructed to provide validation data sets for the energy performance model and design tool. The envelopes of both houses are very energy efficient and airtight, and the HERS ratings of the homes are 44 and 45 respectively. Both houses are mechanically ventilated with energy recovery ventilators, with space conditioning provided by water-to-air heat pumps with 2 ton nominal capacities. Separate water-to-water heat pumps with 1.5 ton nominal capacities were used for water heating. In these unoccupied research houses, human impact on energy use (hot water draw, etc.) is simulated to match the national average. At House 1 the hybrid FHX/HGHX system was installed in 300 linear feet of excavation, and 60% of that was construction excavation (needed to construct the home). At House 2 the hybrid FHX/HGHX system was installed in 360 feet of excavation, 50% of which was construction excavation. There are six pipes in all excavations (three parallel circuits - out and back), and the multiple instances of FHX and/or HGHX are all connected in series. The working fluid is 20% by weight propylene glycol in water. Model and design tool development was undertaken in parallel with constructing the houses, installing instrumentation, and monitoring performance for a year. Several detailed numerical models for FHX were developed as part of the project. Essentially the project team was searching for an energy performance model accurate enough to achieve project objectives while also having sufficient computational efficiency for practical use in EnergyPlus. A 3-dimensional, dual-coordinate-system, finite-volume model satisfied these criteria and was included in the October 2011 EnergyPlus Version 7 public release after being validated against measured data.« less

Evolution of mud-capped dredge pits following excavation: sediment trapping and slope instability

NASA Astrophysics Data System (ADS)

Obelcz, J.; Xu, K.; Bentley, S. J.; Li, C.; Miner, M. D.; O'Connor, M. C.; Wang, J.

2016-02-01

Many fluvial channels incised the Northern Gulf of Mexico inner continental shelf during the late Quaternary. Mud-capped dredge pits (MCDPs), which are generally elongate and deep (8-10 m) excavations, target sandy fluvial channel deposits for coastal restoration projects. The morphological evolution of dredge excavations in noncohesive sandy substrate is well studied, but MCDPs have up to a several-meter-thick veneer of Holocene shelf mud overlying sandy channel deposits. This stratigraphy is hypothesized to result in more complex post-dredge morphology than pit walls simply slumping to the angle of repose shortly after excavation. Numerical modeling of MCDP post-dredge response conducted prior to excavation indicates pit walls may retrogressively fail, which is accounted for in pit design by assigning no-dredge setback buffers from pipelines or cultural and environmental resources. To validate model results and test effectiveness of setback buffers, a geophysical survey of the Sandy Point MCDP (20 km west of the Mississippi River Delta in 10m deep water), where 1.7 million m3 of sandy sediment was excavated in 2012, was conducted May 2015. A total of 84 line-km of high-resolution chirp subbottom and a 27 km2 grid of swath bathymetry and sidescan sonar were collected. The data indicate the dredge pit walls are differentially slumping, with the western pit wall in a more active state of failure than the eastern wall. The western failures morphologically resemble features observed along the muddy Mississippi River Delta Front at water depths of 20-100 m, including bowl-shaped collapse failures and retrogressive stair-stepped slumps; these failures may play a key role in evaluating the distance of setback buffer zone to pipelines. These features indicate the cohesive mud overlying the sandy infill has a prominent role in pit wall stability. A 0.5-1 m thick acoustically transparent package overlies the entire pit floor (interpreted as a possible fluid mud layer), overlying 1-3 m of post-dredge deposition that is concentrated along the western wall and center of the pit. The Sandy Point MCDP lies within a clockwise gyre, and its relief may serve as a significant trap of suspended sediment. These findings emphasize the role MCDPs play in sediment dynamics as well as their potential for submarine geohazards.

Excavation Induced Hydraulic Response of Opalinus Clay - Investigations of the FE-Experiment at the Mont Terri URL in Switzerland

NASA Astrophysics Data System (ADS)

Vogt, T.; Müller, H. R.; Garitte, B.; Sakaki, T.; Vietor, T.

2013-12-01

The Full-Scale Emplacement (FE) Experiment at the Mont Terri underground research laboratory in Switzerland is a full-scale heater test in a clay-rich formation (Opalinus Clay). Based on the Swiss disposal concept it simulates the construction, emplacement, backfilling, and post-closure thermo-hydro-mechanical (THM) evolution of a spent fuel / vitrified high-level waste (SF / HLW) repository tunnel in a realistic manner. The main aim of this experiment is to investigate SF / HLW repository-induced THM coupled effects mainly in the host rock but also in the engineered barrier system (EBS), which consists of bentonite pellets and blocks. A further aim is to gather experience with full-scale tunnel construction and associated hydro-mechanical (HM) processes in the host rock. The entire experiment implementation (in a 50 m long gallery with approx. 3 m diameter) as well as the post-closure THM evolution will be monitored using a network of several hundred sensors (state-of-the-art sensors and measurement systems as well as fiber-optic sensors). The sensors are distributed in the host rock's near- and far-field, the tunnel lining, the EBS, and on the heaters. The heater emplacement and backfilling has not started yet, therefore only the host rock instrumentation is installed at the moment and is currently generating data. We will present the instrumentation concept and rationale as well as the first monitoring results of the excavation and ventilation phase. In particular, we investigated the excavation induced hydraulic response of the host rock. Therefore, the spatiotemporal evolution of porewater-pressure time series was analyzed to get a better understanding of HM coupled processes during and after the excavation phase as well as the impact of anisotropic geomechanic and hydraulic properties of the clay-rich formation on its hydraulic behavior. Excavation related investigations were completed by means of inclinometer data to characterize the non-elastic and time-dependent deformations. In addition, we evaluated the effect of drainage and suction processes during the ventilation phase on the pressure distribution in the host rock. Based on our results the conceptual models of HM processes and hydraulic behavior of clay rich formations during excavation and ventilation phases could be improved.

Archaeology of Void Spaces

NASA Astrophysics Data System (ADS)

Look, Cory

The overall goal of this research is to evaluate the efficacy of pXRF for the identification of ancient activity areas at Pre-Columbian sites in Antigua that range across time periods, geographic regions, site types with a variety of features, and various states of preservation. These findings have important implications for identifying and reconstructing places full of human activity but void of material remains. A synthesis for an archaeology of void spaces requires the construction of new ways of testing anthrosols, and identifying elemental patterns that can be used to connect people with their places and objects. This research begins with an exploration of rich middens in order to study void spaces. Midden archaeology has been a central focus in Caribbean research, and consists of an accumulation of discarded remnants from past human activities that can be tested against anthrosols. The archaeological collections visited for this research project involved creating new databases to generate a comprehensive inventory of sites, materials excavated, and assemblages available for study. Of the more than 129 Pre-Columbian sites documented in Antigua, few sites have been thoroughly surveyed or excavated. Twelve Pre-Columbian sites, consisting of thirty-six excavated units were selected for study; all of which contained complete assemblages for comparison and soil samples for testing. These excavations consisted almost entirely of midden excavations, requiring new archaeological investigations to be carried out in spaces primarily void of material remains but within the village context. Over the course of three seasons excavations, shovel test pits, and soil augers were used to obtain a variety of anthrosols and archaeological assemblages in order to generate new datasets to study Pre-Columbian activity areas. The selection of two primary case study sites were used for comparison: Indian Creek and Doigs. Findings from this research indicate that accounting for the variety of activity areas that make up a site can imbue a site with an identity of purpose and shed light on how different sites may have served different purposes within a regional framework. Excavations at the site of Indian Creek identified a series of raised middens that enclosed an open space for approximately 1500 years. This research explores this open space, and questions the meaning of 'void' and 'empty' with respect to past human activities. While archaeologists recognize that areas void of material remains are certainly part of the larger site, the question remains, without an understand of these spaces; what aspects of past life are we possibly masking? The integration of anthrosols alongside archaeological excavations and spatial analysis indicate that the site of Indian Creek contained a ceremonial plaza that formed early on and was maintained until abandonment. The spatial distribution of material objects combined with anthrosol studies provided additional evidence of ritual deposits concentrated in one part of the plaza associated with a nearby creek-bed. The second site, Doigs represents one of the last intact undisturbed Early Ceramic Age site of its kind in the Eastern Caribbean. Since its discovery in the 1970's, Doig's has been partially surveyed and excavated. The identification of residential activity areas including several potential structures, bead manufacturing loci, and cooking hearths were used to help test chemical signatures with archaeologically defined activity areas. Findings from this site illustrated the uniqueness of elemental patterns associated with activity areas, and also generated new questions regarding void spaces enriched with elemental patterns associated with concentrations of plant and vegetation debris. It is the hope of this study to contribute to our general knowledge for the identification of ancient activity areas as well as the different places that give sites their identity. These assemblages of activity areas can provide Caribbeanists with an alternative approach to studying social organization at a village scale and generate new discussions regarding island wide-community relationships.

Chief Joseph Dam, Columbia River, Washington, Additional Units and Structural Modification Foundation Report

DTIC Science & Technology

1988-01-01

diameter companion drain holes in the area below the intake structure. The second contract, DACW67-75-C-0042, was awarded to Goodfellow Brothers, Inc. in...tolerances for bolt anchors. Subhori- zontal companion drain holes were drilled adjacent to the rock bolt holes. Negligible ground water was encountered...excavation contract was then modified so that rock excavation would not go below elevation 799 feet. The contractor installed rock bolts and companion drain

EAST FACE OF REACTOR BASE. COMING TOWARD CAMERA IS EXCAVATION ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

EAST FACE OF REACTOR BASE. COMING TOWARD CAMERA IS EXCAVATION FOR MTR CANAL. CAISSONS FLANK EACH SIDE. COUNTERFORT (SUPPORT PERPENDICULAR TO WHAT WILL BE THE LONG WALL OF THE CANAL) RESTS ATOP LEFT CAISSON. IN LOWER PART OF VIEW, DRILLERS PREPARE TRENCHES FOR SUPPORT BEAMS THAT WILL LIE BENEATH CANAL FLOOR. INL NEGATIVE NO. 739. Unknown Photographer, 10/6/1950 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Fouling and Boring of Glass Reinforced Plastic - Balsa Blocks in a Tropical Marine Environment,

DTIC Science & Technology

1983-03-01

borers had decomposed prior to examination of the blocks but eight molluscan species were identified from hard parts (pallets and shells ) found in the...or bivalve molluscs and these differ in their boring habit and subsequently the type of damage they cause. Crustacean borers excavate tunnels several...or teredo, excavate tunnels lined with calcium carbonate to accomodate their elongate bodies which, in some species, can be up to 2m long. They feed

Fractionation of Pb and Cu in the fine fraction (<10 mm) of waste excavated from a municipal landfill.

PubMed

Kaczala, Fabio; Orupõld, Kaja; Augustsson, Anna; Burlakovs, Juris; Hogland, Marika; Bhatnagar, Amit; Hogland, William

2017-11-01

The fractionation of metals in the fine fraction (<10 mm) of excavated waste from an Estonian landfill was carried out to evaluate the metal (Pb and Cu) contents and their potential towards not only mobility but also possibilities of recovery/extraction. The fractionation followed the BCR (Community Bureau of Reference) sequential extraction, and the exchangeable (F1), reducible (F2), oxidizable (F3) and residual fractions were determined. The results showed that Pb was highly associated with the reducible (F2) and oxidizable (F3) fractions, suggesting the potential mobility of this metal mainly when in contact with oxygen, despite the low association with the exchangeable fraction (F1). Cu has also shown the potential for mobility when in contact with oxygen, since high associations with the oxidizable fraction (F3) were observed. On the other hand, the mobility of metals in excavated waste can be seen as beneficial considering the circular economy and recovery of such valuables back into the economy. To conclude, not only the total concentration of metals but also a better understanding of fractionation and in which form metals are bound is very important to bring information on how to manage the fine fraction from excavated waste both in terms of environmental impacts and also recovery of such valuables in the economy.

Hollow Cylinder Tests on Boom Clay: Modelling of Strain Localization in the Anisotropic Excavation Damaged Zone

NASA Astrophysics Data System (ADS)

François, Bertrand; Labiouse, Vincent; Dizier, Arnaud; Marinelli, Ferdinando; Charlier, Robert; Collin, Frédéric

2014-01-01

Boom Clay is extensively studied as a potential candidate to host underground nuclear waste disposal in Belgium. To guarantee the safety of such a disposal, the mechanical behaviour of the clay during gallery excavation must be properly predicted. In that purpose, a hollow cylinder experiment on Boom Clay has been designed to reproduce, in a small-scale test, the Excavation Damaged Zone (EDZ) as experienced during the excavation of a disposal gallery in the underground. In this article, the focus is made on the hydro-mechanical constitutive interpretation of the displacement (experimentally obtained by medium resolution X-ray tomography scanning). The coupled hydro-mechanical response of Boom Clay in this experiment is addressed through finite element computations with a constitutive model including strain hardening/softening, elastic and plastic cross-anisotropy and a regularization method for the modelling of strain localization processes. The obtained results evidence the directional dependency of the mechanical response of the clay. The softening behaviour induces transient strain localization processes, addressed through a hydro-mechanical second grade model. The shape of the obtained damaged zone is clearly affected by the anisotropy of the materials, evidencing an eye-shaped EDZ. The modelling results agree with experiments not only qualitatively (in terms of the shape of the induced damaged zone), but also quantitatively (for the obtained displacement in three particular radial directions).

New knowledge-based genetic algorithm for excavator boom structural optimization

NASA Astrophysics Data System (ADS)

Hua, Haiyan; Lin, Shuwen

2014-03-01

Due to the insufficiency of utilizing knowledge to guide the complex optimal searching, existing genetic algorithms fail to effectively solve excavator boom structural optimization problem. To improve the optimization efficiency and quality, a new knowledge-based real-coded genetic algorithm is proposed. A dual evolution mechanism combining knowledge evolution with genetic algorithm is established to extract, handle and utilize the shallow and deep implicit constraint knowledge to guide the optimal searching of genetic algorithm circularly. Based on this dual evolution mechanism, knowledge evolution and population evolution can be connected by knowledge influence operators to improve the configurability of knowledge and genetic operators. Then, the new knowledge-based selection operator, crossover operator and mutation operator are proposed to integrate the optimal process knowledge and domain culture to guide the excavator boom structural optimization. Eight kinds of testing algorithms, which include different genetic operators, are taken as examples to solve the structural optimization of a medium-sized excavator boom. By comparing the results of optimization, it is shown that the algorithm including all the new knowledge-based genetic operators can more remarkably improve the evolutionary rate and searching ability than other testing algorithms, which demonstrates the effectiveness of knowledge for guiding optimal searching. The proposed knowledge-based genetic algorithm by combining multi-level knowledge evolution with numerical optimization provides a new effective method for solving the complex engineering optimization problem.

Review of Cuttability Indices and A New Rockmass Classification Approach for Selection of Surface Miners

NASA Astrophysics Data System (ADS)

Dey, Kaushik; Ghose, A. K.

2011-09-01

Rock excavation is carried out either by drilling and blasting or using rock-cutting machines like rippers, bucket wheel excavators, surface miners, road headers etc. Economics of mechanised rock excavation by rock-cutting machines largely depends on the achieved production rates. Thus, assessment of the performance (productivity) is important prior to deploying a rock-cutting machine. In doing so, several researchers have classified rockmass in different ways and have developed cuttability indices to correlate machine performance directly. However, most of these indices were developed to assess the performance of road headers/tunnel-boring machines apart from a few that were developed in the earlier days when the ripper was a popular excavating equipment. Presently, around 400 surface miners are in operation around the world amongst which, 105 are in India. Until now, no rockmass classification system is available to assess the performance of surface miners. Surface miners are being deployed largely on trial and error basis or based on the performance charts provided by the manufacturer. In this context, it is logical to establish a suitable cuttability index to predict the performance of surface miners. In this present paper, the existing cuttability indices are reviewed and a new cuttability indexes proposed. A new relationship is also developed to predict the output from surface miners using the proposed cuttability index.

Remedial Action Plan and site design for stabilization of the inactive uranium mill tailings site at Durango, Colorado: Attachment 6, Supplemental standard for Durango processing site. Revised final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1991-12-01

Excavation control to the 15 pCi/g radium-226 (Ra-226) standard at certain areas along the Animas River on the Durango Site would require extensive engineering and construction support. Elevated Ra-226 concentrations have been encountered immediately adjacent to the river at depths in excess of 7 feet below the present river stage. Decontamination to such depths to ensure compliance with the EPA standards will, in our opinion, become unreasonable. This work does not appear to be in keeping with the intent of the standards. Because the principal reason for radium removal is reduction of radon daughter concentrations (RDC) in homes to bemore » built onsite, and because radon produced at depth will be attenuated in clean fill cover before entering such homes, it is appropriate to calculate the depth of excavation needed under a home to reduce RDC to acceptable levels. Potential impact was assessed through radon emanation estimation, using the RAECOM computer model. Elevated Ra-226 concentrations were encountered during final radium excavation of the flood plain below the large tailings pile, adjacent to the slag area. Data from 7 test pits excavated across the area were analyzed to provide an estimate of the Ra-226 concentration profile. Results are given in this report.« less

Noachian and more recent phyllosilicates in impact craters on Mars

PubMed Central

Fairén, Alberto G.; Chevrier, Vincent; Abramov, Oleg; Marzo, Giuseppe A.; Gavin, Patricia; Davila, Alfonso F.; Tornabene, Livio L.; Bishop, Janice L.; Roush, Ted L.; Gross, Christoph; Kneissl, Thomas; Uceda, Esther R.; Dohm, James M.; Schulze-Makuch, Dirk; Rodríguez, J. Alexis P.; Amils, Ricardo; McKay, Christopher P.

2010-01-01

Hundreds of impact craters on Mars contain diverse phyllosilicates, interpreted as excavation products of preexisting subsurface deposits following impact and crater formation. This has been used to argue that the conditions conducive to phyllosilicate synthesis, which require the presence of abundant and long-lasting liquid water, were only met early in the history of the planet, during the Noachian period (> 3.6 Gy ago), and that aqueous environments were widespread then. Here we test this hypothesis by examining the excavation process of hydrated minerals by impact events on Mars and analyzing the stability of phyllosilicates against the impact-induced thermal shock. To do so, we first compare the infrared spectra of thermally altered phyllosilicates with those of hydrated minerals known to occur in craters on Mars and then analyze the postshock temperatures reached during impact crater excavation. Our results show that phyllosilicates can resist the postshock temperatures almost everywhere in the crater, except under particular conditions in a central area in and near the point of impact. We conclude that most phyllosilicates detected inside impact craters on Mars are consistent with excavated preexisting sediments, supporting the hypothesis of a primeval and long-lasting global aqueous environment. When our analyses are applied to specific impact craters on Mars, we are able to identify both pre- and postimpact phyllosilicates, therefore extending the time of local phyllosilicate synthesis to post-Noachian times. PMID:20616087

Noachian and more recent phyllosilicates in impact craters on Mars.

PubMed

Fairén, Alberto G; Chevrier, Vincent; Abramov, Oleg; Marzo, Giuseppe A; Gavin, Patricia; Davila, Alfonso F; Tornabene, Livio L; Bishop, Janice L; Roush, Ted L; Gross, Christoph; Kneissl, Thomas; Uceda, Esther R; Dohm, James M; Schulze-Makuch, Dirk; Rodríguez, J Alexis P; Amils, Ricardo; McKay, Christopher P

2010-07-06

Hundreds of impact craters on Mars contain diverse phyllosilicates, interpreted as excavation products of preexisting subsurface deposits following impact and crater formation. This has been used to argue that the conditions conducive to phyllosilicate synthesis, which require the presence of abundant and long-lasting liquid water, were only met early in the history of the planet, during the Noachian period (> 3.6 Gy ago), and that aqueous environments were widespread then. Here we test this hypothesis by examining the excavation process of hydrated minerals by impact events on Mars and analyzing the stability of phyllosilicates against the impact-induced thermal shock. To do so, we first compare the infrared spectra of thermally altered phyllosilicates with those of hydrated minerals known to occur in craters on Mars and then analyze the postshock temperatures reached during impact crater excavation. Our results show that phyllosilicates can resist the postshock temperatures almost everywhere in the crater, except under particular conditions in a central area in and near the point of impact. We conclude that most phyllosilicates detected inside impact craters on Mars are consistent with excavated preexisting sediments, supporting the hypothesis of a primeval and long-lasting global aqueous environment. When our analyses are applied to specific impact craters on Mars, we are able to identify both pre- and postimpact phyllosilicates, therefore extending the time of local phyllosilicate synthesis to post-Noachian times.

Regolith Advanced Surface Systems Operations Robot (RASSOR)

NASA Technical Reports Server (NTRS)

Mueller, Robert P.; Smith, Jonathan D.; Cox, Rachel E.; Schuler, Jason M.; Ebert, Tom; Nick, Andrew J.

2012-01-01

Regolith is abundant on extra-terrestrial surfaces and is the source of many resources such as oxygen, hydrogen, titanium, aluminum, iron, silica and other valuable materials, which can be used to make rocket propellant, consumables for life support, radiation protection barrier shields, landing pads, blast protection berms, roads, habitats and other structures and devices. Recent data from the Moon also indicates that there are substantial deposits of water ice in permanently shadowed crater regions and possibly under an over burden of regolith. The key to being able to use this regolith and acquire the resources, is being able to manipulate it with robotic excavation and hauling machinery that can survive and operate in these very extreme extra-terrestrial surface environments. In addition, the reduced gravity on the Moon, Mars, comets and asteroids poses a significant challenge in that the necessary reaction force for digging cannot be provided by the robot's weight as is typically done on Earth. Space transportation is expensive and limited in capacity, so small, lightweight payloads are desirable, which means large traditional excavation machines are not a viable option. A novel, compact and lightweight excavation robot prototype for manipulating, excavating, acquiring, hauling and dumping regolith on extra-terrestrial surfaces has been developed and tested. Lessons learned and test results will be presented including digging in a variety of lunar regolith simulant conditions including frozen regolith mixed with water ice.

Methods to ensure the quality of excavated soil material from geogenically metalliferous sites

NASA Astrophysics Data System (ADS)

Liebhard, Peter; Sager, Manfred

2017-04-01

Soils at geogenically metalliferous sites might exceed heavy metal threshold levels with respect to agricultural use, apart from anthropogenic contamination sources. As a fundamental substrate for green plants and green plant production, soil is not easily renewable, its formation needs long time (e.g. 500 years for 20 mm). In Austria, about 10ha of soil get sealed every day, resulting in complete loss of its biological functions. Excavated soil material has been classified as waste from a legal point of view, which made 33 mill. tons resp. 48% of total waste in Austria in 2010. Recycling of excavated soil material for agricultural use will be an important task to reduce future waste and to enlarge agricultural substrate volumes, but methods to ensure proper qualities are needed to improve regulations. Within this investigation, the transfer of various metals from geogenically metalliferous soils to various crop plants will be investigated, and correlated with various simple soil test methods. Four excavated soil materials from the metalliferous schist zone within the Austrian province of Styria (Kraubath/Mur, Übelbach) and a low-metal reference sample have been taken as substrates to grow raygrass (lolium multiflorum) as a green cover, salad (Lactuca sativa) as a vegetable food item, oats (Avena sativa), maize (Zea mais) and stinging nettle (Urtica dioica) as a hyperaccumulating species. Results and recommendations will be presented.

Large Deformation Characteristics and Reinforcement Measures for a Rock Pillar in the Houziyan Underground Powerhouse

NASA Astrophysics Data System (ADS)

Xiao, Xin-hong; Xiao, Pei-wei; Dai, Feng; Li, Hai-bo; Zhang, Xue-bin; Zhou, Jia-wen

2018-02-01

The underground powerhouse of the Houziyan Hydropower Station is under the conditions of high geo-stress and a low strength/stress ratio, which leads to significant rock deformation and failures, especially for rock pillars due to bidirectional unloading during the excavation process. Damages occurred in thinner rock pillars after excavation due to unloading and stress concentration, which will reduce the surrounding rock integrity and threaten the safety of the underground powerhouse. By using field investigations and multi-source monitoring data, the deformation and failure characteristics of a rock pillar are analyzed from the tempo-spatial distribution features. These results indicate that significant deformation occurred in the rock pillar when the powerhouse was excavated to the fourth layer, and the maximum displacement reached 107.57 mm, which occurred on the main transformer chamber upstream sidewall at an elevation of 1721.20 m. The rock deformation surrounding the rock pillar is closely related to the excavation process and has significant time-related characteristics. To control large deformation of the rock pillar, thru-anchor cables were used to reinforce the rock pillar to ensure the stability of the powerhouse. The rock deformation surrounding the rock pillar decreases gradually and forms a convergent trend after reinforcement measures are installed based on the analysis of the temporal characteristics and the rock pillar deformation rate.

Cuttability Assessment of Selected Rocks Through Different Brittleness Values

NASA Astrophysics Data System (ADS)

Dursun, Arif Emre; Gokay, M. Kemal

2016-04-01

Prediction of cuttability is a critical issue for successful execution of tunnel or mining excavation projects. Rock cuttability is also used to determine specific energy, which is defined as the work done by the cutting force to excavate a unit volume of yield. Specific energy is a meaningful inverse measure of cutting efficiency, since it simply states how much energy must be expended to excavate a unit volume of rock. Brittleness is a fundamental rock property and applied in drilling and rock excavation. Brittleness is one of the most crucial rock features for rock excavation. For this reason, determination of relations between cuttability and brittleness will help rock engineers. This study aims to estimate the specific energy from different brittleness values of rocks by means of simple and multiple regression analyses. In this study, rock cutting, rock property, and brittleness index tests were carried out on 24 different rock samples with different strength values, including marble, travertine, and tuff, collected from sites around Konya Province, Turkey. Four previously used brittleness concepts were evaluated in this study, denoted as B 1 (ratio of compressive to tensile strength), B 2 (ratio of the difference between compressive and tensile strength to the sum of compressive and tensile strength), B 3 (area under the stress-strain line in relation to compressive and tensile strength), and B 9 = S 20, the percentage of fines (<11.2 mm) formed in an impact test for the Norwegian University of Science and Technology (NTNU) model as well as B 9p (B 9 as predicted from uniaxial compressive, Brazilian tensile, and point load strengths of rocks using multiple regression analysis). The results suggest that the proposed simple regression-based prediction models including B 3, B 9, and B 9p outperform the other models including B 1 and B 2 and can be used for more accurate and reliable estimation of specific energy.

Remediation of a Former USAF Radioactive Material Disposal Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoffman, D. E.; Cushman, M; Tupyi, B.

2003-02-25

This paper describes the remediation of a low-level radiological waste burial site located at the former James Connally Air Force Base in Waco, Texas. Burial activities at the site occurred during the 1950's when the property was under the ownership of the United States Air Force. Included is a discussion of methods and strategies that were used to successfully exhume and characterize the wastes for proper disposal at offsite disposal facilities. Worker and environmental protection measures are also described. Information gained from this project may be used at other similar project sites. A total of nine burial tubes had beenmore » identified for excavation, characterization, and removal from the site. The disposal tubes were constructed of 4-ft lengths of concrete pipe buried upright with the upper ends flush with ground surface. Initial ground level observations of the burial tubes indicated that some weathering had occurred; however, the condition of the subsurface portions of the tubes was unknown. Soil excavation occurred in 1-foot lifts in order that the tubes could be inspected and to allow for characterization of the soils at each stage of the excavation. Due to the weight of the concrete pipe and the condition of the piping joints it was determined that special measures would be required to maintain the tubes intact during their removal. Special tube anchoring and handling methods were required to relocate the tubes from their initial positions to a staging area where they could be further characterized. Characterization of the disposal tubes was accomplished using a combination of gamma spectroscopy and activity mapping methods. Important aspects of the project included the use of specialized excavation and disposal tube reinforcement measures to maintain the disposal tubes intact during excavation, removal and subsequent characterization. The non-intrusive gamma spectroscopy and data logging methods allowed for effective characterization of the wastes while minimizing disposal costs. In addition, worker exposures were maintained ALARA as a result of the removal and characterization methods employed.« less

A Study on the Prediction of Damage Extent at the Time of Perforating Operation on Reinforced Concrete Structure through Horizontal Excavation

NASA Astrophysics Data System (ADS)

Lee, Ju-hyoung; Kim, Hakman; Cho, Jin Woo

2017-04-01

When a building collapses in downtown due to a sudden external factor such as earthquake, gas explosion or terror, the rescue of a survivor in the buried area should be prioritized. When a collapse accident occurs in downtown, there is a difficulty of access to the surrounding area of the collapsed building site due to building debris and a risk of the second collapse, and it takes a lot of time to rescue any survivor in the top excavation method to rescue while removing building debris. Therefore, there is a method to rescue any survivor safely by installing the second lifeline after securing the first lifeline within 72 hours using inclined excavation near the site of collapsed building or horizontal excavation at the underground parking lot of an adjacent building and prolonging the life of any survivor. When a building collapses in downtown, the perforating operation is carried out at the existing structure in the process of establishing the first lifeline to the position of a survivor through the parking lot of an adjacent building or the external wall of the building, and the damage extent in case of carrying out such operation was confirmed in this study. In order to determine the stability of the damaged existing structure and the range of repair, the reinforced concrete wall was produced and the damage extent of the reinforced concrete for each perforating position was measured by installing a measuring instrument at a position separated by 150%˜200% from the perforating position. As a result, it was shown that the average damage area for each perforating position was influenced within approximately a 254% radius. Keywords: horizontal excavation, damage, reinforced roncrete, building collapses Acknowledgement This research was supported by a Grant from a Strategic Research Project (Horizontal Drilling and Stabilization Technologies for Urban Search and Rescue (US&R) Operation) funded by the Korea Institute of Civil Engineering and Building Technology.

Uav Surveying for a Complete Mapping and Documentation of Archaeological Findings. The Early Neolithic Site of Portonovo

NASA Astrophysics Data System (ADS)

Malinverni, E. S.; Conati Barbaro, C.; Pierdicca, R.; Bozzi, C. A.; Tassetti, A. N.

2016-06-01

The huge potential of 3D digital acquisition techniques for the documentation of archaeological sites, as well as the related findings, is almost well established. In spite of the variety of available techniques, a sole documentation pipeline cannot be defined a priori because of the diversity of archaeological settings. Stratigraphic archaeological excavations, for example, require a systematic, quick and low cost 3D single-surface documentation because the nature of stratigraphic archaeology compels providing documentary evidence of any excavation phase. Only within a destructive process each single excavation cannot be identified, documented and interpreted and this implies the necessity of a re- examination of the work on field. In this context, this paper describes the methodology, carried out during the last years, to 3D document the Early Neolithic site of Portonovo (Ancona, Italy) and, in particular, its latest step consisting in a photogrammetric aerial survey by means of UAV platform. It completes the previous research delivered in the same site by means of terrestrial laser scanning and close range techniques and sets out different options for further reflection in terms of site coverage, resolution and campaign cost. With the support of a topographic network and a unique reference system, the full documentation of the site is managed in order to detail each excavation phase; besides, the final output proves how the 3D digital methodology can be completely integrated with reasonable costs during the excavation and used to interpret the archaeological context. Further contribution of this work is the comparison between several acquisition techniques (i.e. terrestrial and aerial), which could be useful as decision support system for different archaeological scenarios. The main objectives of the comparison are: i) the evaluation of 3D mapping accuracy from different data sources, ii) the definition of a standard pipeline for different archaeological needs and iii) the provision of different level of detail according to the user needs.

Robotic excavator trajectory control using an improved GA based PID controller

NASA Astrophysics Data System (ADS)

Feng, Hao; Yin, Chen-Bo; Weng, Wen-wen; Ma, Wei; Zhou, Jun-jing; Jia, Wen-hua; Zhang, Zi-li

2018-05-01

In order to achieve excellent trajectory tracking performances, an improved genetic algorithm (IGA) is presented to search for the optimal proportional-integral-derivative (PID) controller parameters for the robotic excavator. Firstly, the mathematical model of kinematic and electro-hydraulic proportional control system of the excavator are analyzed based on the mechanism modeling method. On this basis, the actual model of the electro-hydraulic proportional system are established by the identification experiment. Furthermore, the population, the fitness function, the crossover probability and mutation probability of the SGA are improved: the initial PID parameters are calculated by the Ziegler-Nichols (Z-N) tuning method and the initial population is generated near it; the fitness function is transformed to maintain the diversity of the population; the probability of crossover and mutation are adjusted automatically to avoid premature convergence. Moreover, a simulation study is carried out to evaluate the time response performance of the proposed controller, i.e., IGA based PID against the SGA and Z-N based PID controllers with a step signal. It was shown from the simulation study that the proposed controller provides the least rise time and settling time of 1.23 s and 1.81 s, respectively against the other tested controllers. Finally, two types of trajectories are designed to validate the performances of the control algorithms, and experiments are performed on the excavator trajectory control experimental platform. It was demonstrated from the experimental work that the proposed IGA based PID controller improves the trajectory accuracy of the horizontal line and slope line trajectories by 23.98% and 23.64%, respectively in comparison to the SGA tuned PID controller. The results further indicate that the proposed IGA tuning based PID controller is effective for improving the tracking accuracy, which may be employed in the trajectory control of an actual excavator.

SFTYCHEF: A Consultative, Diagnostic Expert System for Trench Excavation Safety Analysis on Light Commercial Construction Projects.

DTIC Science & Technology

1987-03-30

Safe Trench Excavation ...... 2 Applicability to Solution via Expert System. 3 Background: Expert Systems ..................... 4 Definition of an...trench, drownings in the trench, and other mishaps which are the result of a lack of S C- proper consideration for safe construction practices. Although...the problem is not a new one, there is as yet no *" obvious method that will guarantee a safe trench. In addition, the expertise needed to provide case

Santa Ana River Design Memorandum Number 1. Phase 2 GDM on the Santa Ana River Mainstem Including Santiago Creek. Volume 2. Prado Dam.

DTIC Science & Technology

1988-08-01

present and likely to be encountered during excavation. Nonetheless, the four groups do provide an adequate method for representing the different ...It different from Report) Approved for Public Release; Distribution Unlimited IS. SUPPLEMENTARY NOTES IS. KEY WORDS (Continue on reverse M e II...between the dam embankment and the spillway. The two 800-foot long conduits would be constructed by open excavation and backfill method . Downstream

The Evolution of Oblique Impact Flow Fields Using Maxwell's Z Model

NASA Technical Reports Server (NTRS)

Anderson, J. L. B.; Schultz, P. H.; Heineck, J. T.

2003-01-01

Oblique impacts are the norm rather than the exception for impact craters on planetary surfaces. This work focuses on the excavation of experimental oblique impact craters using the NASA Ames Vertical Gun Range (AVGR). Three-dimensional particle image velocimetry (3D PIV) is used to obtain quantitative data on ejection positions, three dimensional velocities and angles. These data are then used to constrain Maxwell's Z Model and follow the subsurface evolution of the excavation-stage flow-field center during oblique impacts.

Archaeological Investigations in the Gainesville Lake Area of the Tennessee-Tombigbee Waterway. Volume I. The Gainesville Lake Area Excavations.

DTIC Science & Technology

1981-01-01

97 71. Site 1Pi61, Removing Trees ........ .................. . 97 72. Site lPi6l, Testing the Midden ....... ................ . 97 6...the use of plant and animal species changes through time. Volume IV also describes the human skeletal remains from all excavated sites and discusses the...Gainesville Lake area were cultural features. A few 5 features resulted from forces other than human behavior ( tree roots, ro- dent burrows, erosional gullies

Archaeological Test Excavations of the Historic Component of 45-WT-1 Texas City/Riparia, Whitman County, Washington, 1983.

DTIC Science & Technology

1984-01-01

information on the history of Riparia and visited the site during excavations, identifying areas of the historic town. Della Mae Evans also shared with us the...only historic overview photograph we had seen of Riparia and led us to 1967 newspaper articles about the final demise of the town. Jerry Jones of the...Colfax Gazette tracked down photographs of Riparia which had been taken in 1966 and provided us with copies. Washing, processing, and cataloguing of

Calculation of stresses in a rock mass and lining in stagewise face drivage

NASA Astrophysics Data System (ADS)

Seryakov, VM; Zhamalova, BR

2018-03-01

Using the method of calculating mechanical state of a rock mass for the conditions of stagewise drivage of a production face in large cross-section excavations, the specific features of stress redistribution in lining of excavations are found. The zones of tensile stresses in the lining are detected. The authors discuss the influence of the initial stress state of rocks on the tension stress zones induced in the lining in course of the heading advance

Archeological Investigations in Cochiti Reservoir, New Mexico. Volume 2. Excavation and Analysis 1975 Season.

DTIC Science & Technology

1977-01-01

groups who used this ratio should be considered. them to process wild seeds and other vegeta material. The trough metate has been considered a specialized...transition and as an indi- was composed entirely of jar formswith wide oriface. cation of the importance assumed by wild vegetal ma- not as difficult to...For example. Ovis/Capra meat is con- faunal resource utilization from the excavated site loca- sidered most edible when the animal is young. Meat

Measurement of carbon storage in landfills from the biogenic carbon content of excavated waste samples.

PubMed

De la Cruz, Florentino B; Chanton, Jeffrey P; Barlaz, Morton A

2013-10-01

Landfills are an anaerobic ecosystem and represent the major disposal alternative for municipal solid waste (MSW) in the U.S. While some fraction of the biogenic carbon, primarily cellulose (Cel) and hemicellulose (H), is converted to carbon dioxide and methane, lignin (L) is essentially recalcitrant. The biogenic carbon that is not mineralized is stored within the landfill. This carbon storage represents a significant component of a landfill carbon balance. The fraction of biogenic carbon that is not reactive in the landfill environment and therefore stored was derived for samples of excavated waste by measurement of the total organic carbon, its biogenic fraction, and the remaining methane potential. The average biogenic carbon content of the excavated samples was 64.6±18.0% (average±standard deviation), while the average carbon storage factor was 0.09±0.06g biogenic-C stored per g dry sample or 0.66±0.16g biogenic-C stored per g biogenic C. Published by Elsevier Ltd.

Shallow magma diversions during explosive diatreme-forming eruptions.

PubMed

Le Corvec, Nicolas; Muirhead, James D; White, James D L

2018-04-13

The diversion of magma is an important mechanism that may lead to the relocation of a volcanic vent. Magma diversion is known to occur during explosive volcanic eruptions generating subterranean excavation and remobilization of country and volcanic rocks. However, feedbacks between explosive crater formation and intrusion processes have not been considered previously, despite their importance for understanding evolving hazards during volcanic eruptions. Here, we apply numerical modeling to test the impacts of excavation and subsequent infilling of diatreme structures on stress states and intrusion geometries during the formation of maar-diatreme complexes. Explosive excavation and infilling of diatremes affects local stress states which inhibits magma ascent and drives lateral diversion at various depths, which are expected to promote intra-diatreme explosions, host rock mixing, and vent migration. Our models demonstrate novel mechanisms explaining the generation of saucer-shaped sills, linked with magma diversion and enhanced intra-diatreme explosive fragmentation during maar-diatreme volcanism. Similar mechanisms will occur at other volcanic vents producing crater-forming eruptions.

KSC-2011-4154

NASA Image and Video Library

2011-05-28

CAPE CANAVERAL, Fla. -- A remote controlled or autonomous excavator, called a lunabot, is on display outside of the "Lunarena" at the Kennedy Space Center Visitor Complex in Florida where university students maneuver their remote controlled lunabots, in a "sand box" of ultra-fine simulated lunar soil during NASA's second annual Lunabotics Mining Competition. Thirty-six teams of undergraduate and graduate students from the United States, Bangladesh, Canada, Colombia and India will participate in NASA's Lunabotics Mining Competition May 26 - 28 at the agency's Kennedy Space Center in Florida. The competition is designed to engage and retain students in science, technology, engineering and mathematics (STEM). Teams will maneuver their remote controlled or autonomous excavators, called lunabots, in about 60 tons of ultra-fine simulated lunar soil, called BP-1. The competition is an Exploration Systems Mission Directorate project managed by Kennedy's Education Division. The event also provides a competitive environment that could result in innovative ideas and solutions for NASA's future excavation of the moon. Photo credit: NASA/Jack Pfaller

RCRA Facility Investigation/Remedial Investigation Report for Gunsite 720 Rubble Pit Unit (631-16G) - March 1996

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palmer, E.

1996-03-01

Gunsite 720 Rubble Pit Unit is located on the west side of SRS. In the early to mid 1980`s, while work was being performed in this area, nine empty, partially buried drums, labeled `du Pont Freon 11`, were found. As a result, Gunsite 720 became one of the original waste units specified in the SRS RCRA Facility Assessment (RFA). The drums were excavated on July 30, 1987 and placed on a pallet at the unit. Both the drums and pallet were removed and disposed of in October 1989. The area around the drums was screened during the excavation and themore » liquid (rainwater) that collected in the excavated drums was sampled prior to disposal. No evidence of hazardous materials was found. Based on the review of the analytical data and screening techniques used to evaluate all the chemicals of potential concern at Gunsite 720 Rubble Pit Unit, it is recommended that no further remedial action be performed at this unit.« less

KSC-2011-4148

NASA Image and Video Library

2011-05-27

CAPE CANAVERAL, Fla. -- While an event judge looks on, university students monitor their team's remote controlled or autonomous excavator, called a lunabot, as it is maneuvered in a "sand box" of ultra-fine simulated lunar soil during NASA's second annual Lunabotics Mining Competition at the Kennedy Space Center Visitor Complex in Florida. Thirty-six teams of undergraduate and graduate students from the United States, Bangladesh, Canada, Colombia and India will participate in NASA's Lunabotics Mining Competition May 26 - 28 at the agency's Kennedy Space Center in Florida. The competition is designed to engage and retain students in science, technology, engineering and mathematics (STEM). Teams will maneuver their remote controlled or autonomous excavators, called lunabots, in about 60 tons of ultra-fine simulated lunar soil, called BP-1. The competition is an Exploration Systems Mission Directorate project managed by Kennedy's Education Division. The event also provides a competitive environment that could result in innovative ideas and solutions for NASA's future excavation of the moon. Photo credit: NASA/Jack Pfaller

GPR Investigations in the Port of Erythrai (İzmir) Archaeological Site

NASA Astrophysics Data System (ADS)

Timur, Emre; Sarı, Coşkun; Erhan, Zülfikar; Gül Akalın Orbay, Ayşe

2016-04-01

Archaeology and the cultural heritage field can greatly benefit from reliable and non-destructive geophysical methods to map areas and structures present in the subsoil without the need for excavation. The GPR method provides coherent and interpretable images of the subsurface structures due to good signal penetration. Erythrai archaeological site is located in Çeşme district of city of İzmir (Turkey). The site has been excavated since 1960's and a great demand appeared nowadays for exploring unexcavated parts, according to improving touristic potential. Ground Penetrating Radar (GPR) measurements were carried out at the ancient port of the site. Study area was splitted into 4 parts and data were collected along 130 profiles with a profile interval of 1 m and varying lengths between 20 and 30 m. Data were interpreted and presented as 2-D vertical radargrams, horizontal time slices and 3-D models. As a result, possible ruins of shipment or fisherman shelters were determined and excavation areas were recommended.

Theoretical Investigations on the Influence of Artificially Altered Rock Mass Properties on Mechanical Excavation

NASA Astrophysics Data System (ADS)

Hartlieb, Philipp; Bock, Stefan

2018-03-01

This study presents a theoretical analysis of the influence of the rock mass rating on the cutting performance of roadheaders. Existing performance prediction models are assessed for their suitability for forecasting the influence of pre-damaging the rock mass with alternative methods like lasers or microwaves, prior to the mechanical excavation process. Finally, the RMCR model was chosen because it is the only reported model incorporating a range of rock mass properties into its calculations. The results show that even very tough rocks could be mechanically excavated if the occurrence, orientation and condition of joints are favourable for the cutting process. The calculated improvements in the cutting rate (m3/h) are up to 350% for the most favourable cases. In case of microwave irradiation of hard rocks with an UCS of 200 MPa, a reasonable improvement in the performance by 120% can be achieved with as little as an extra 0.7 kWh/m3 (= 1% more energy) compared to cutting only.

Ancient palace complex (300–100 BC) discovered in the Valley of Oaxaca, Mexico

PubMed Central

Redmond, Elsa M.; Spencer, Charles S.

2017-01-01

Recently completed excavations at the site of El Palenque in Mexico’s Valley of Oaxaca have recovered the well-preserved remains of a palace complex dated by associated radiocarbon samples and ceramics to the Late Formative period or Late Monte Albán I phase (300–100 BC), the period of archaic state emergence in the region. The El Palenque palace exhibits certain architectural and organizational features similar to the royal palaces of much later Mesoamerican states described by Colonial-period sources. The excavation data document a multifunctional palace complex covering a maximum estimated area of 2,790 m2 on the north side of the site’s plaza and consisting of both governmental and residential components. The data indicate that the palace complex was designed and built as a single construction. The palace complex at El Palenque is the oldest multifunctional palace excavated thus far in the Valley of Oaxaca. PMID:28348218

The Tissint Martian meteorite as evidence for the largest impact excavation.

PubMed

Baziotis, Ioannis P; Liu, Yang; DeCarli, Paul S; Melosh, H Jay; McSween, Harry Y; Bodnar, Robert J; Taylor, Lawrence A

2013-01-01

High-pressure minerals in meteorites provide clues for the impact processes that excavated, launched and delivered these samples to Earth. Most Martian meteorites are suggested to have been excavated from 3 to 7 km diameter impact craters. Here we show that the Tissint meteorite, a 2011 meteorite fall, contains virtually all the high-pressure phases (seven minerals and two mineral glasses) that have been reported in isolated occurrences in other Martian meteorites. Particularly, one ringwoodite (75 × 140 μm(2)) represents the largest grain observed in all Martian samples. Collectively, the ubiquitous high-pressure minerals of unusually large sizes in Tissint indicate that shock metamorphism was widely dispersed in this sample (~25 GPa and ~2,000 °C). Using the size and growth kinetics of the ringwoodite grains, we infer an initial impact crater with ~90 km diameter, with a factor of 2 uncertainty. These energetic conditions imply alteration of any possible low-T minerals in Tissint.

Three-Dimensional Laser Scanning for Geometry Documentation and Construction Management of Highway Tunnels during Excavation

PubMed Central

Gikas, Vassilis

2012-01-01

Driven by progress in sensor technology, computer software and data processing capabilities, terrestrial laser scanning has recently proved a revolutionary technique for high accuracy, 3D mapping and documentation of physical scenarios and man-made structures. Particularly, this is of great importance in the underground space and tunnel construction environment as surveying engineering operations have a great impact on both technical and economic aspects of a project. This paper discusses the use and explores the potential of laser scanning technology to accurately track excavation and construction activities of highway tunnels. It provides a detailed overview of the static laser scanning method, its principles of operation and applications for tunnel construction operations. Also, it discusses the planning, execution, data processing and analysis phases of laser scanning activities, with emphasis given on geo-referencing, mesh model generation and cross-section extraction. Specific case studies are considered based on two construction sites in Greece. Particularly, the potential of the method is examined for checking the tunnel profile, producing volume computations and validating the smoothness/thickness of shotcrete layers at an excavation stage and during the completion of excavation support and primary lining. An additional example of the use of the method in the geometric documentation of the concrete lining formwork is examined and comparisons against dimensional tolerances are examined. Experimental comparisons and analyses of the laser scanning method against conventional surveying techniques are also considered. PMID:23112655

Microseismic monitoring of columnar jointed basalt fracture activity: a trial at the Baihetan Hydropower Station, China

NASA Astrophysics Data System (ADS)

Chen, Bing-Rui; Li, Qing-Peng; Feng, Xia-Ting; Xiao, Ya-Xun; Feng, Guang-Liang; Hu, Lian-Xing

2014-10-01

Severe stress release has occurred to the surrounding rocks of the typically columnar jointed basalt after excavation at the Baihetan Hydropower Station, Jinsha River, China, where cracking, collapse, and other types of failure may take place occasionally due to relaxation fracture. In order to understand the relaxation fracture characteristics of the columnar jointed basalt in the entire excavation process at the diversion tunnel of the Baihetan Hydropower Station, real-time microseismic monitoring tests were performed. First, the applicability of a geophone and accelerometer was analyzed in the columnar jointed basalt tunnel, and the results show that the accelerometer was more applicable to the cracking monitoring of the columnar jointed basalt. Next, the waveform characteristics of the microseismic signals were analyzed, and the microseismic signals were identified as follows: rock fracture signal, drilling signal, electrical signal, heavy vehicle passing signal, and blast signal. Then, the attenuation characteristics of the microseismic signals in the columnar jointed basalt tunnel were studied, as well as the types and characteristics of the columnar jointed basalt fracture. Finally, location analysis was conducted on the strong rock fracture events, in which four or more sensors were triggered, to obtain the temporal and spatial evolution characteristics and laws of the columnar jointed basalt relaxation fracture after excavation. The test results are not only of important reference value to the excavation and support of diversion tunnel at the Baihetan Hydropower Station, but also of great referential significance and value to the conduction of similar tests.

Microbial excavation of solid carbonates powered by P-type ATPase-mediated transcellular Ca2+ transport.

PubMed

Garcia-Pichel, Ferran; Ramírez-Reinat, Edgardo; Gao, Qunjie

2010-12-14

Some microbes, among them a few species of cyanobacteria, are able to excavate carbonate minerals, from limestone to biogenic carbonates, including coral reefs, in a bioerosive activity that directly links biological and geological parts of the global carbon cycle. The physiological mechanisms that enable such endolithic cyanobacteria to bore, however, remain unknown. In fact, their boring constitutes a geochemical paradox, in that photoautotrophic metabolism will tend to precipitate carbonates, not dissolve them. We developed a stable microbe/mineral boring system based on a cyanobacterial isolate, strain BC008, with which to study the process of microbial excavation directly in the laboratory. Measurements of boring into calcite under different light regimes, and an analysis of photopigment content and photosynthetic rates along boring filaments, helped us reject mechanisms based on the spatial or temporal separation of alkali versus Acid-generating metabolism (i.e., photosynthesis and respiration). Instead, extracellular Ca(2+) imaging of boring cultures in vivo showed that BC008 was able to take up Ca(2+) at the excavation front, decreasing the local extracellular ion activity product of calcium carbonate enough to promote spontaneous dissolution there. Intracellular Ca(2+) was then transported away along the multicellular cyanobacterial trichomes and excreted at the distal borehole opening into the external medium. Inhibition assays and gene expression analyses indicate that the uptake and transport was driven by P-type Ca(2+)-ATPases. We believe such a chemically simple and biologically sophisticated mechanism for boring to be unparalleled among bacteria.

Cultural Resource Investigations within the U.S. Army Corps of Engineers New Orleans to Venice Hurricane Protection Project

DTIC Science & Technology

1988-12-01

0.5 km north of the town of Phoenix, along the Joe Gravolet Canal. In 1923, when the Gravolet Canal was being excavated, the dredge pulled up a few hewn...when the Gravolet Canal was excavated, the dredge pulled up a few hewn timbers purportedly associated with the Fort. Based on these remains and other...be used in the determination of trade networks (Research Goal 2), and the level of technology used at the factory and living areas (Research Goali 3

Downstream Stockton Study, Sac River. Phase 2 Archaeological Test Excavations at Sites 23CE324, 23CE235 and 23CE252 with Discussion of Test Excavation at Sites 23CE240 and 23CE241

DTIC Science & Technology

1988-01-01

area and vicinity. ............ a . . . . . . 34 Table 4. Rodgers Shelter culture sequence and Horizon Projectile Point Series...deposits evidence considerable Holocene aggradation (Brackenridge 1981). This alluvial deposition, referred to as the Rodgers alluvium (Haynes 1977), has...relatively high frequencies of grassland species and small game were exploited at Rodgers Shelter (McMillan 1976b:229), and it was surmised (Kay 1978) that

The Evolution of Oblique Impact Flow Fields Using Maxwell's Z Model

NASA Technical Reports Server (NTRS)

Anderson, J. L. B.; Schultz, P. H.; Heineck, J. T.

2003-01-01

Oblique impacts are the norm rather than the exception for impact craters on planetary surfaces. This work focuses on the excavation of experimental oblique impact craters using the NASA Ames Vertical Gun Range (AVGR). Three-dimensional particle image velocimetry (3D PIV) is used to obtain quantitative data on ejection positions, three-dimensional velocities and angles. These data are then used to test the applicability and limitations of Maxwell's Z Model in representing the subsurface evolution of the excavation-stage flow-field center during vertical and oblique impacts.

Bug Hill: Excavation of a Multicomponent Midden Mound in the Jackfork Valley, Pushmataha County, Southeast Oklahoma.

DTIC Science & Technology

1983-11-25

program of survey and excavation on at least 24 sites, 18 of which were black midden mounds, along the Poteau River and Fourche Maline Creek in the area of...evidence, from the Fourche Maline Creek sites. These are deep sites with four feet or more of midden... Evidently, it was not possible to separate this... Maline Creek 15 to 20 mi west of present Wister Lake. At this site, Powell and Rodgers (1980:5-9) carefully examined the stratigraphic context of each

Risk of groundwater inrush in subterranean gypsum quarries: the case study of Moncalvo near Asti (North Italy)

NASA Astrophysics Data System (ADS)

Banzato, Cinzia; Fiorucci, Adriano; Gianotti, Alberto; de Waele, Jo; Vigna, Bartolomeo

2010-05-01

During the realisation of underground excavations in gypsum bedrock there is a possibility of intercepting large karst voids that can be completely filled with water under a considerable hydraulic pressure. The casual breaching of such voids can cause sudden and abundant water inrushes with consequences concerning safety of the excavation area and flooding of the tunnels. The presence of air-filled caves of great dimensions can also cause problems related to collapse of walls, ceilings and floors. In the subterranean quarry of Moncalvo d'Asti (Central Piedmont, Italy) in January 2005 an important inrush (60,000 m3 overnight) occurred causing damage to machinery and the flooding of several kilometres of underground tunnels. This inrush was caused by the breaching of a thin diaphragm of rock that separated the quarry from a large water-filled cave with water pressure of around 300 kPa along the front of the excavation. The rapid emptying of this void has caused a partial collapse of the roof of one of the largest cave chambers with the formation at the surface of a 20 metre wide sinkhole. To prevent similar phenomena to happen in the future a hydrogeological study concerning the entire gypsum mass was carried out. These investigations included monitoring of water levels intercepted by a series of boreholes, measurements of flow rates of water veins encountered by the excavations and chemical analysis of the different types of water coming from several points. This study has evidenced the presence of different drainage networks and the existence of a main karst circuit fed by diffused infiltration and recharge from the overlying marly-silty deposits and from adjacent minor less karstified systems in particularly fractured sectors of the gypsum. The waters coming from the main karst circuit are chemically very different from the waters deriving from deeper pathways. To be able to continue the excavation of gypsum in safe conditions the water levels were lowered for a couple of metres through the realisation of a series of boreholes located at lower elevations. These boreholes have intercepted the most conductive aquifer developed along a marly limestone level located at the base of the Messinian evaporite sequence. Some near-horizontal drill holes carried out along the front of the excavations have also been realised and have intercepted a second karst system with water under pressure (> 300 kPa), independent from the main one. A controlled drainage is now being carried out (30 l/s) to slowly lower the hydraulic head so to avoid future collapse of these new karst voids. Some geophysical surveys have also been carried out to discover other karst voids of great dimensions, but these did not give positive results. The performed investigations have shown the importance of hydrogeological studies and speleological surveys in understanding better the development of the karst systems and in the realisation of the excavation activities in conditions of safety, allowing to avoid expensive interruptions of the mining operations.

Modelisation numerique de tunnels de metro dans les massifs rocheux sedimentaires de la region de Montreal

NASA Astrophysics Data System (ADS)

Lavergne, Catherine

Geological formations of the Montreal area are mostly made of limestones. The usual approach for design is based on rock mass classification systems considering the rock mass as an equivalent continuous and isotropic material. However, for shallow excavations, stability is generally controlled by geological structures, that in Montreal, are bedding plans that give to the rock mass a strong strain and stress anisotropy. Objects of the research are to realize a numerical modeling that considers sedimentary rocks anisotropy and to determine the influence of the design parameters on displacements, stresses and failure around metro unsupported underground excavations. Geotechnical data used for this study comes from a metro extension project and has been made available to the author. The excavation geometries analyzed are the tunnel, the station and a garage consisting of three (3) parallel tunnels for rock covered between 4 and 16 m. The numerical modeling has been done with FLAC software that represents continuous environment, and ubiquitous joint behavior model to simulate strength anisotropy of sedimentary rock masses. The model considers gravity constraints for an anisotropic material and pore pressures. In total, eleven (11) design parameters have been analyzed. Results show that unconfined compressive strength of intact rock, fault zones and pore pressures in soils have an important influence on the stability of the numerical model. The geometry of excavation, the thickness of rock covered, the RQD, Poisson's ratio and the horizontal tectonic stresses have a moderate influence. Finally, ubiquitous joint parameters, pore pressures in rock mass, width of the pillars of the garage and the damage linked to the excavation method have a low impact. FLAC results have been compared with those of UDEC, a software that uses the distinct element method. Similar conclusions were obtained on displacements, stress state and failure modes. However, UDEC model give slightly less conservative results than FLAC. This study stands up by his local character and the large amount of geotechnical data available used to determine parameters of the numerical model. The results led to recommendations for laboratory tests that can be applied to characterize more specifically anisotropy of sedimentary rocks.

The effect of hillslope angle on pocket gopher (Thomomys bottae) burrow geometry.

PubMed

Seabloom, E W; Reichman, O J; Gabet, E J

2000-10-01

One way for animals to decrease energy expenditures is to minimize the cost of movement. For animals dwelling on slopes, gravity can impart a large energetic cost to movement. For this reason, animals traveling aboveground alter their movement patterns in response to the steepness of terrain (specifically hillslope angle) so as to minimize their energetic costs. Subterranean animals should also benefit from choosing optimum movement paths in relation to hillslopes but concurrently must factor the cost of excavation into their movement decisions. In cases where the excavation costs are much higher than the costs of working against gravity, excavation costs may override the consideration of gravitational costs and movement of subterranean animals may be independent of hillslope angle. To determine the response of a subterranean animal to hillslope angle, we excavated tunnels in the burrow systems of 19 pocket gophers in southern California that occupied hillslopes ranging from 2 to 30°. At each excavation we measured several characteristics of burrow geometry and used these data in a model of pocket gopher energetics to calculate the cost of tunnel construction at the various hillslope angles. We found that the cost of tunnel construction was independent of hillslope angle, and that the costs of shearing soil and pushing soil horizontally through the tunnels were 3 orders of magnitude greater than the costs of lifting the soil against the force of gravity. Accordingly, pocket gopher foraging tunnels were oriented independently of the hillslope. The decoupling of the movement patterns of subterranean animals from the effects of gravity is a distinctive feature of the subterranean habit compared to the movement of aboveground animals. Because of the important effects of tunnel construction on soil processes, this unique biological feature of subterranean animals has implications for basic physical processes, such as soil erosion. We found that the rate of soil flux generated by pocket gopher activity was invariant to hillslope. This relationship is in contrast to the most common model of soil movement generated by purely physical processes.

An evaluation of applicability of seismic refraction method in identifying shallow archaeological features A case study at archaeological site

NASA Astrophysics Data System (ADS)

Jahangardi, Morteza; Hafezi Moghaddas, Naser; Keivan Hosseini, Sayyed; Garazhian, Omran

2015-04-01

We applied the seismic refraction method at archaeological site, Tepe Damghani located in Sabzevar, NE of Iran, in order to determine the structures of archaeological interests. This pre-historical site has special conditions with respect to geographical location and geomorphological setting, so it is an urban archaeological site, and in recent years it has been used as an agricultural field. In spring and summer of 2012, the third season of archaeological excavation was carried out. Test trenches of excavations in this site revealed that cultural layers were often disturbed adversely due to human activities such as farming and road construction in recent years. Conditions of archaeological cultural layers in southern and eastern parts of Tepe are slightly better, for instance, in test trench 3×3 m²1S03, third test trench excavated in the southern part of Tepe, an adobe in situ architectural structure was discovered that likely belongs to cultural features of a complex with 5 graves. After conclusion of the third season of archaeological excavation, all of the test trenches were filled with the same soil of excavated test trenches. Seismic refraction method was applied with12 channels of P geophones in three lines with a geophone interval of 0.5 meter and a 1.5 meter distance between profiles on test trench 1S03. The goal of this operation was evaluation of applicability of seismic method in identification of archaeological features, especially adobe wall structures. Processing of seismic data was done with the seismic software, SiesImager. Results were presented in the form of seismic section for every profile, so that identification of adobe wall structures was achieved hardly. This could be due to that adobe wall had been built with the same materials of the natural surrounding earth. Thus, there is a low contrast and it has an inappropriate effect on seismic processing and identifying of archaeological features. Hence the result could be that application of the seismic method in order to determine the archaeological features, having the same conditions, is not affordable and efficient in comparison to GPR or magnetic methods which yield more desirable results.

In-Situ Hydraulic Conductivities of Soils and Anomalies at a Future Biofuel Production Site

NASA Astrophysics Data System (ADS)

Williamson, M. F.; Jackson, C. R.; Hale, J. C.; Sletten, H. R.

2010-12-01

Forested hillslopes of the Upper Coastal Plain at the Savannah River Site, SC, feature a shallow clay loam argillic layer with low median saturated hydraulic conductivity. Observations from a grid of shallow, maximum-rise piezometers indicate that perching on this clay layer is common. However, flow measurements from an interflow-interception trench indicate that lateral flow is rare and most soil water percolates through the clay layer. We hypothesize that the lack of frequent lateral flow is due to penetration of the clay layer by roots of pine trees. We used ground penetrating radar (GPR) to map the soil structure and potential anomalies, such as root holes, down to two meters depth at three 10×10-m plots. At each plot, a 1×10-m trench was later back-hoe excavated along a transect that showed the most anomalies on the GPR maps. Each trench was excavated at 0.5-m intervals until the clay layer was reached (two plots were excavated to a final depth of 0.875 m and the third plot was excavated to a final depth of 1.0 m). At each interval, compact constant-head permeameters (CCHPs) were used to measure in-situ hydraulic conductivities in the clay-loam matrix and in any visually apparent anomalies. Conductivity was also estimated using a second 1×10-m transect of CCHP measurements taken within randomly placed augur holes. Additional holes targeted GPR anomalies. The second transect was created in case the back-hoe impacted conductivity readings. High-conductivity anomalies were also visually investigated by excavating with a shovel. Photographs of soil wetness were taken at visually apparent anomalies with a multispectral camera. We discovered that all visually apparent anomalies found are represented on the GPR maps, but that not all of the predicted anomalies on the GPR maps are visually apparent. We discovered that tree root holes create anomalies, but that there were also many conductivity anomalies that could not be visually distinguished from low-conductivity soil.

New Design Concept for an Excavator Arms by Using Composite Material

NASA Astrophysics Data System (ADS)

Solazzi, L.; Assi, A.; Ceresoli, F.

2018-06-01

The purpose of the present paper is to lightweight design an excavator arms, by using a different materials and in particular composite material. Specifically, the research is based on the study of a commercial excavator, by determining its geometry and analyzing the load conditions to which it is exposed. These are determined in relation to either the load diagram of the machine or the possible utilities of the excavator, such as the rotation of the machine. The materials used and implemented in the different analytical and numerical elaborations are classic construction steel S 355 (UNI EN 10025-3), high-resistance steel S 890 (UNI EN 10025-6), aluminum Al 6063 T6 (UNI EN 573-3) and the composite material made by carbon fiber and epoxy resin. The adopted constraints for the design of new arms with different materials, non-conventional for these applications, are numerous. The new solutions must present a safety factor either with respect to the yield tensile strength or to the critical load of buckling greater than or equal to the one determined for the excavator in its original geometrical conformation. Another criterion, which has heavily conditioned the geometry of the arms, was given by the fact that the developed solutions must present a very similar value of the maximum displacement in the different load conditions analyzed. A new geometry for arms made by composite material was developed. It was an elliptical conic section, instead of the classic rectangular section, in order to use the filament winding technological process. As for the adoption of the composite material, we focused on the study and the design of this material as long as the interaction with the extremities (made of aluminum) which are interfaced either with the link between the arms or with the elements of the hydraulic plant which serves for the arms movement. From the results developed, it emerges that the solution developed by adopting composite materials is the one that permits the maximum weight reduction for all arms, about 68.1%, which can be seen as an increment of the maximum mass transportable about 45.5% i.e. passing from 5000 kg to 7277 kg.

Soil Segregation Methods for Reducing Transportation and Disposal Costs - 13544

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frothingham, David; Andrews, Shawn; Barker, Michelle

2013-07-01

At Formerly Utilized Sites Remedial Action Program (FUSRAP) sites where the selected alternative for contaminated soil is excavation and off-site disposal, the most significant budget items of the remedial action are the costs for transportation and disposal of soil at an off-site facility. At these sites, the objective is to excavate and dispose of only those soils that exceed derived concentration guideline levels. In situ soil segregation using gross gamma detectors to guide the excavation is often challenging at sites where the soil contamination is overlain by clean soil or where the contaminated soil is located in isolated, subsurface pockets.more » In addition, data gaps are often identified during the alternative evaluation and selection process, resulting in increased uncertainty in the extent of subsurface contamination. In response, the U.S. Army Corps of Engineers, Buffalo District is implementing ex situ soil segregation methods. At the remediated Painesville Site, soils were excavated and fed through a conveyor-belt system, which automatically segregated them into above- and below-cleanup criteria discharge piles utilizing gamma spectroscopy. At the Linde Site and the Shallow Land Disposal Area (SLDA) Site, which are both in the remediation phase, soils are initially segregated during the excavation process using gross gamma detectors and then transported to a pad for confirmatory manual surveying and sampling. At the Linde Site, the ex situ soils are analyzed on the basis of a site-specific method, to establish compliance with beneficial reuse criteria that were developed for the Linde remediation. At the SLDA Site, the ex situ soils are surveyed and sampled based on Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) final status survey guidance to demonstrate compliance with the derived concentration guideline levels. At all three sites, the ex situ soils that meet the site- specific DCGLs are retained on-site and used as backfill material. This paper describes the ex situ soil segregation methods, the considerations of each method, and the estimated cost savings from minimizing the volume of soil requiring transportation and off-site disposal. (authors)« less

Effect of river excavation on a bank filtration site - assessing transient surface water - groundwater interaction by 3D heat and solute transport modelling

NASA Astrophysics Data System (ADS)

Wang, W.; Oswald, S. E.; Munz, M.; Strasser, D.

2017-12-01

Bank filtration is widely used either as main- or pre-treatment process for water supply. The colmation of the river bottom as interface to groundwater plays a key role for hydraulic control of flow paths and location of several beneficial attenuation processes, such as pathogen filtration, mixing, biodegradation and sorption. Along the flow path, mixing happens between the `young' infiltrated water and ambient `old' groundwater. To clarify the mechanisms and their interaction, modelling is often used for analysing spatial and temporal distribution of the travelling time, quantifying mixing ratios, and estimating the biochemical reaction rates. As the most comprehensive tool, 2-D or 3-D spatially-explicit modelling is used in several studies, and for area with geological heterogeneity, the adaptation of different natural tracers could constrain the model in respect to model non-uniqueness and improve the interpretation of the flow field. In our study, we have evaluated the influence of a river excavation and bank reconstruction project on the groundwater-surface water exchange at a bank filtration site. With data from years of field site monitoring, we could include besides heads and temperature also the analysis of stable isotope data and ions to differentiate between infiltrated water and groundwater. Thus, we have set up a 3-D transient heat and mass transport groundwater model, taking the strong local geological heterogeneity into consideration, especially between river and water work wells. By transferring the effect of the river excavation into a changing hydraulic conductivity of the riverbed, model could be calibrated against both water head and temperature time-series observed. Finally, electrical conductivity dominated by river input was included as quasi-conservative tracer. The `triple' calibrated, transient model was then used to i) understand the flow field and quantify the long term changes in infiltration rate and distribution brought by the excavation ii) compare among temperature, electrical conductivity and stable isotope values calculated and interpret the performance and deviations iii) analyse from this modelling basis about the implications of the excavation induced changes on further water quality data and travelling time distributions, also with seasonal aspects.

Airborne asbestos fibres monitoring in tunnel excavation.

PubMed

Gaggero, Laura; Sanguineti, Elisa; Yus González, Adrián; Militello, Gaia Maria; Scuderi, Alberto; Parisi, Giovanni

2017-07-01

Tunnelling across ophiolitic formation with Naturally Occurring Asbestos (NOA) can release fibres into the environment, exposing workers, and the population, if fibres spread outside the tunnel, leading to increased risk of developing asbestos-related disease. Therefore, a careful plan of environmental monitoring is carried out during Terzo Valico tunnel excavation. In the present study, data of 1571 samples of airborne dust, collected between 2014 and 2016 inside the tunnels, and analyzed by SEM-EDS for quantification of workers exposure, are discussed. In particular, the engineering and monitoring management of 100 m tunnelling excavation across a serpentinite lens (Cravasco adit), intercalated within calcschists, is reported. At this chrysotile occurrence, 84% of 128 analyzed samples (from the zone closer to the front rock) were above 2 ff/l. However, thanks to safety measures implemented and tunnel compartmentation in zones, the asbestos fibre concentration did not exceed the Italian standard of occupational exposure (100 ff/l) and 100% of samples collected in the outdoor square were below 1 ff/l. During excavation under normal working conditions, asbestos concentrations were below 2 ff/l in 97.4% of the 668 analyzed samples. Our results showed that air monitoring can objectively confirm the presence of asbestos minerals at a rock front in relative short time and provide information about the nature of the lithology at the front. The present dataset, the engineering measures described and the operative conclusions are liable to support the improvement of legislation on workers exposure to asbestos referred to the tunnelling sector, lacking at present. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of focal choroidal excavation in the macula using swept-source optical coherence tomography.

PubMed

Lim, F P M; Loh, B K; Cheung, C M G; Lim, L S; Chan, C M; Wong, D W K

2014-09-01

To evaluate imaging findings of patients with focal choroidal excavation (FCE) in the macula using swept-source optical coherence tomography (SS-OCT) and correlate it clinically. Prospective observational case series. Eleven consecutive patients (12 eyes) with FCE were described. Data on demographics and clinical presentation were collected and imaging findings (including color photography, fundus autofluorescence imaging, fluorescein angiography, indocyanine green angiography, spectral-domain optical coherence tomography, and SS-OCT) were analyzed. The primary diagnosis was epiretinal membrane (two eyes), choroidal neovascularization (one eye), polypoidal choroidal vasculopathy (three eyes), central serous chorioretinopathy (one eye), and dry age-related macular degeneration (two eyes). Eleven out of 12 of the lesions were conforming. One presented with a non-conforming lesion that progressed to a conforming lesion. One eye had multiFCE and two had two overlapping choroidal excavations. Using the SS-OCT, we found the choroid to be thinned out at the area of FCE but sclera remained normal. The choroidal tissue beneath the FCE was abnormal, with high internal reflectivity and poor visualization of choroidal vessels. There was loss of contour of the outer choroidal boundary that appeared to be pulled inward by this abnormal choroidal tissue. A suprachoroidal space was noted beneath this choroidal tissue and the choroidal-scleral interface was smooth. Repeat SS-OCT 6 months after presentation showed the area of excavation to be stable in size. FCE can be associated with epiretinal membrane, central serous chorioretinopathy, and age-related macular degeneration. The choroid was thinned out in the area of FCE.

Evaluation of focal choroidal excavation in the macula using swept-source optical coherence tomography

PubMed Central

Lim, F P M; Loh, B K; Cheung, C M G; Lim, L S; Chan, C M; Wong, D W K

2014-01-01

Purpose To evaluate imaging findings of patients with focal choroidal excavation (FCE) in the macula using swept-source optical coherence tomography (SS-OCT) and correlate it clinically. Methods Prospective observational case series. Eleven consecutive patients (12 eyes) with FCE were described. Data on demographics and clinical presentation were collected and imaging findings (including color photography, fundus autofluorescence imaging, fluorescein angiography, indocyanine green angiography, spectral-domain optical coherence tomography, and SS-OCT) were analyzed. Results The primary diagnosis was epiretinal membrane (two eyes), choroidal neovascularization (one eye), polypoidal choroidal vasculopathy (three eyes), central serous chorioretinopathy (one eye), and dry age-related macular degeneration (two eyes). Eleven out of 12 of the lesions were conforming. One presented with a non-conforming lesion that progressed to a conforming lesion. One eye had multiFCE and two had two overlapping choroidal excavations. Using the SS-OCT, we found the choroid to be thinned out at the area of FCE but sclera remained normal. The choroidal tissue beneath the FCE was abnormal, with high internal reflectivity and poor visualization of choroidal vessels. There was loss of contour of the outer choroidal boundary that appeared to be pulled inward by this abnormal choroidal tissue. A suprachoroidal space was noted beneath this choroidal tissue and the choroidal–scleral interface was smooth. Repeat SS-OCT 6 months after presentation showed the area of excavation to be stable in size. Conclusion FCE can be associated with epiretinal membrane, central serous chorioretinopathy, and age-related macular degeneration. The choroid was thinned out in the area of FCE. PMID:24946847

The legacy of Pompeii and its volcano.

PubMed

de Divitiis, Enrico; Cappabianca, Paolo; Esposito, Felice; Cavallo, Luigi M

2004-10-01

On August 24, AD 79, a terrible eruption of Mount Vesuvius deranged life in beautiful Pompeii and killed thousands of men, women, and children. They were restored to us by the fact that Mount Vesuvius, with its rain of ashes, proved to be a skilled sculptor, preserving the shape and even the wrinkles in the clothes the Pompeians wore while trying to escape during the day of the tragedy. The detailed description of Plinius the Younger and modern static studies of the eruptive residues have made it possible to reconstruct with great accuracy the various phases of the eruption that took place 2000 years ago, including the hours and days during which the phenomena first became obvious. Today, almost 2000 years later, Pompeii has reawakened and risen from its sepulcher of ashes thanks to the excavations initiated under King Charles III of Bourbon in 1748. Excavations proceeded slowly under the Bourbons, with the aim of enriching the Bourbon Museum of Naples rather than of classifying the ruins and placing them into a historical context. Under Joachim Murat, interest in the town planning and architecture of the uncovered cities reemerged, especially with respect to Pompeii. In 1860, however, with the establishment of the Kingdom of Italy, the excavations, now under the direction of archaeologist Giuseppe Fiorelli, were provided new impetus and, finally, a scientific basis. Today, the excavations are giving us back extraordinary evidence concerning the culture, the everyday life, the habits, the architecture, and the wonderful frescoes of the Roman cities of southern Italy, making possible the statement that Pompeii is "the most alive of the dead cities."

Case study on impact performance optimization of hydraulic breakers.

PubMed

Noh, Dae-Kyung; Kang, Young-Ky; Cho, Jae-Sang; Jang, Joo-Sup

2016-01-01

In order to expand the range of activities of an excavator, attachments, such as hydraulic breakers have been developed to be applied to buckets. However, it is very difficult to predict the dynamic behavior of hydraulic impact devices such as breakers because of high non-linearity. Thus, the purpose of this study is to optimize the impact performance of hydraulic breakers. The ultimate goal of the optimization is to increase the impact energy and impact frequency and to reduce the pressure pulsation of the supply and return lines. The optimization results indicated that the four parameters used to optimize the impact performance of the breaker showed considerable improvement over the results reported in the literature. A test was also conducted and the results were compared with those obtained through optimization in order to verify the optimization results. The comparison showed an average relative error of 8.24 %, which seems to be in good agreement. The results of this study can be used to optimize the impact performance of hydraulic impact devices such as breakers, thus facilitating its application to excavators and increasing the range of activities of an excavator.

Target and Projectile: Material Effects on Crater Excavation and Growth

NASA Technical Reports Server (NTRS)

Anderson, J. L. B.; Burleson, T.; Cintala, Mark J.

2010-01-01

Scaling relationships allow the initial conditions of an impact to be related to the excavation flow and final crater size and have proven useful in understanding the various processes that lead to the formation of a planetary-scale crater. In addition, they can be examined and tested through laboratory experiments in which the initial conditions of the impact are known and ejecta kinematics and final crater morphometry are measured directly. Current scaling relationships are based on a point-source assumption and treat the target material as a continuous medium; however, in planetary-scale impacts, this may not always be the case. Fragments buried in a megaregolith, for instance, could easily approach or exceed the dimensions of the impactor; rubble-pile asteroids could present similar, if not greater, structural complexity. Experiments allow exploration into the effects of target material properties and projectile deformation style on crater excavation and dimensions. This contribution examines two of these properties: (1) the deformation style of the projectile, ductile (aluminum) or brittle (soda-lime glass) and (2) the grain size of the target material, 0.5-1 mm vs. 1-3 mm sand.

First Paleoparasitological Report on the Animal Feces of Bronze Age Excavated from Shahr-e Sukhteh, Iran.

PubMed

Makki, Mahsasadat; Dupouy-Camet, Jean; Sajjadi, Seyed Mansour Seyed; Naddaf, Saied Reza; Mobedi, Iraj; Rezaeian, Mostafa; Mohebali, Mehdi; Mowlavi, Gholamreza

2017-04-01

Shahr-e Sukhteh (meaning burnt city in Persian) in Iran is an archeological site dated back to around 3,200-1,800 BC. It is located in Sistan and Baluchistan Province of Iran and known as the junction of Bronze Age trade routes crossing the Iranian plateau. It was appointed as current study area for paleoparasitological investigations. Excavations at this site have revealed various archeological materials since 1967. In the present study, sheep and carnivore coprolites excavated from this site were analyzed by means of rehydration technique using TSP solution for finding helminth eggs. Dicrocoelium dendriticum, Capillaria sp., and Taenia sp. eggs were identified, while some other objects similar to Anoplocephalidae and Toxocara spp. eggs were also retrieved from the samples but their measured parameters did not match those of these species. The present paper illustrates the first paleoparasitological findings of Bronze Age in eastern Iran supporting the economic activities, peopling, and communication as well as the appropriate condition for zoonotic helminthiasis life cycle in Shahr-e Sukhteh archeological site.

First Paleoparasitological Report on the Animal Feces of Bronze Age Excavated from Shahr-e Sukhteh, Iran

PubMed Central

Makki, Mahsasadat; Dupouy-Camet, Jean; Sajjadi, Seyed Mansour Seyed; Naddaf, Saied Reza; Mobedi, Iraj; Rezaeian, Mostafa; Mohebali, Mehdi; Mowlavi, Gholamreza

2017-01-01

Shahr-e Sukhteh (meaning burnt city in Persian) in Iran is an archeological site dated back to around 3,200-1,800 BC. It is located in Sistan and Baluchistan Province of Iran and known as the junction of Bronze Age trade routes crossing the Iranian plateau. It was appointed as current study area for paleoparasitological investigations. Excavations at this site have revealed various archeological materials since 1967. In the present study, sheep and carnivore coprolites excavated from this site were analyzed by means of rehydration technique using TSP solution for finding helminth eggs. Dicrocoelium dendriticum, Capillaria sp., and Taenia sp. eggs were identified, while some other objects similar to Anoplocephalidae and Toxocara spp. eggs were also retrieved from the samples but their measured parameters did not match those of these species. The present paper illustrates the first paleoparasitological findings of Bronze Age in eastern Iran supporting the economic activities, peopling, and communication as well as the appropriate condition for zoonotic helminthiasis life cycle in Shahr-e Sukhteh archeological site. PMID:28506043

Natural versus anthropogenic genesis of mardels (closed depressions) on the Gutland plateau (Luxembourg); archaeometrical and palynological evidence of Roman clay excavation from mardels.

NASA Astrophysics Data System (ADS)

van Mourik, Jan; Braekmans, Dennis; Doorenbosch, Marieke; Kuijper, Wim; van der Plicht, Hans

2016-04-01

Mardels, small closed depressions, are distinctive landforms on the Luxembourger Gutland plateau. In the present landscape most mardels are shallow fens, filled with colluvial sediments. The genesis of mardels has been studied intensively, inside and outside Luxembourg. Some researchers suggested a natural development and consider mardels as subsidence basins due to subsurface solution of gypsum veins, other researchers suggested cultural causes and consider mardels as prehistorical quarries. In the Gutland, mardels occur on various substrates. Mardels on the Strassen marls (li3) are abandoned quarries, related to clay excavation in Roman Time. Mardels on the Luxembourger sandstone (li2) are sinkholes, related to joint patterns in the sandstone formation. Mardels on the Keuper marls (km1,3) are originally subsidence basins, related to subsurface dissolutions of gypsum lenses and veins, filled with colluvial clay. The results of pollen analysis and archaeometrical tests demonstrate Roman extraction of clay for the production of ancient ceramics. So, the natural depressions have been enlarged to the present mardels. After excavation, the sedimentation of colluvium restarted in the abandoned quarries.

Superfund Record of Decision (EPA Region 5): Summit National Liquid Disposal Service, Deerfield, OH. (First remedial action), (Amendment), November 1990. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

The 11.5-acre Summit National Liquid Disposal Service site is a former liquid waste disposal facility in rural Deerfield Township, Ohio. The site contains two ponds, an inactive incinerator, and several vacant buildings. Surrounding the site are several residences, two landfills, light industries, and farmland. From 1973 to 1978, Summit National operated a solvent recycling and waste disposal facility onsite. The Record of Decision (ROD) amends a 1988 ROD that provided for remediation of contaminated soil, sediment, debris, ground water, and surface water. In both the 1990 proposed remedy for the ROD amendment and the 1988 ROD, the remedy for themore » most highly contaminated soil and sediment is excavation and treatment. The amended remedial action for the site includes expanding site boundaries to include contaminated areas along the site perimeters; excavating and incinerating onsite 24,000 cubic yards of soil excavated to a depth of 2 feet, 4,000 cubic yards of sediment from the site perimeter, drainage ditches and offsite ponds, and 900 to 1,600 buried drums.« less

Excavation on the Moon: Regolith Collection for Oxygen Production and Outpost Site Preparation

NASA Technical Reports Server (NTRS)

Caruso, John J.; Spina, Dan C.; Greer, Lawrence C.; John, Wentworth T.; Michele, Clem; Krasowski, Mike J.; Prokop, Norman F.

2008-01-01

The development of a robust regolith moving system for lunar and planetary processing and construction is critical to the NASA mission to the Moon and Mars. Oxygen production may require up to 200 metric tons of regolith collection per year; outpost site development may require several times this amount. This paper describes progress in the small vehicle implement development and small excavation system development. Cratos was developed as a platform for the ISRU project to evaluate the performance characteristics of a low center of gravity, small (0.75m x 0.75m x 0.3m), low-power, tracked vehicle performing excavation, load, haul, and dump operations required for lunar ISRU. It was tested on loose sand in a facility capable of producing level and inclined surfaces, and demonstrated the capability to pick up, carry, and dump sand, allowing it to accomplish the delivery of material to a site. Cratos has demonstrated the capability to pick up and deliver simulant to a bury an inflatable habitat, to supply an oxygen production plant, and to build a ramp.

Anisotropy of electrical conductivity of the excavation damaged zone in the Mont Terri Underground Rock Laboratory

NASA Astrophysics Data System (ADS)

Nicollin, Florence; Gibert, Dominique; Lesparre, Nolwenn; Nussbaum, Christophe

2010-04-01

Electrical resistivity measurements were performed to characterize the anisotropy of electrical resistivity of the excavation damaged zone (EDZ) at the end-face of a gallery in the Opalinus clay of the Mont Terri Underground Rock Laboratory (URL). The data were acquired with a combination of square arrays in 18 zones on the gallery's face and in two series of four boreholes perpendicular to the face. Each data set is independently inverted using simulated annealing to recover the resistivity tensor. Both the stability and the non-uniqueness of the inverse problem are discussed with synthetic examples. The inversion of the data shows that the face is split in two domains separated by a tectonic fracture, with different resistivity values but with a common orientation. The direction of the maximum resistivity is found perpendicular to the bedding plane, and the direction of minimum resistivity is contained in the face's plane. These results show that the geo-electrical structure of the EDZ is controlled by a combination of effects due to tectonics, stratigraphy, and recent fracturing produced by the excavation of the gallery.

Evaluation of tunnel seismic prediction (TSP) result using the Japanese highway rock mass classification system for Pahang-Selangor Raw Water Transfer Tunnel

NASA Astrophysics Data System (ADS)

Von, W. C.; Ismail, M. A. M.

2017-10-01

The knowing of geological profile ahead of tunnel face is significant to minimize the risk in tunnel excavation work and cost control in preventative measure. Due to mountainous area, site investigation with vertical boring is not recommended to obtain the geological profile for Pahang-Selangor Raw Water Transfer project. Hence, tunnel seismic prediction (TSP) method is adopted to predict the geological profile ahead of tunnel face. In order to evaluate the TSP results, IBM SPSS Statistic 22 is used to run artificial neural network (ANN) analysis to back calculate the predicted Rock Grade Points (JH) from actual Rock Grade Points (JH) using Vp, Vs and Vp/Vs from TSP. The results show good correlation between predicted Rock Grade points and actual Rock Grade Points (JH). In other words, TSP can provide geological profile prediction ahead of tunnel face significantly while allowing continuously TBM excavation works. Identifying weak zones or faults ahead of tunnel face is crucial for preventative measures to be carried out in advance for a safer tunnel excavation works.

Optimization of Archeological Anomalies using GIS method for Magnetic and Resistivity Study at Sungai Batu, Lembah Bujang, Kedah (Malaysia)

NASA Astrophysics Data System (ADS)

Yusoh, R.; Saad, R.; Saidin, M.; Anda, S. T.; Muhammad, S. B.; Ashraf, M. I. M.; Hazreek, Z. A. M.

2018-04-01

Magnetic and resistivity method has become a reliable option in archeological exploration. The use of both method has become popular these day. However, both method gives different type of sensing in detecting anomalies and direct interpret from the anomalies will result large coverage area for excavation. Therefore, to overcome this issue, both anomalies can be extracted using ArcGIS software to reduce excavated coverage area. The case study located at Sungai Batu, Lembah Bujang near SB2ZZ lot expected buried clay brick monument which will be a perfect case to apply this technique. Magnetic and resistivity method was implemented at the study area where the anomalies coverage area for magnetic and resistivity is 531.5 m2 and 636 m2 respectively which total area of both anomalies was 764 m2. By applying combine technique, the anomalies area reduce to 403.7 m2 which reduce the suspected anomalies by 47.16 %. The unsuspected clay brick monument area was increase from 15.86% to 55.54% which improve the cost and labor work for excavation.

Geophysical prospection of the Roman city of Pollentia, Alcúdia (Mallorca, Balearic Islands, Spain)

NASA Astrophysics Data System (ADS)

Ranieri, G.; Godio, A.; Loddo, F.; Stocco, S.; Casas, A.; Capizzi, P.; Messina, P.; Orfila, M.; Cau, M. A.; Chávez, Mª. E.

2016-11-01

We present the results of the geophysical investigation carried out in the Roman city of Pollentia, in the island of Mallorca. The ancient city was identified in the 19th century. Old and new archaeological excavations have helped to uncover a residential area, a theatre, the forum, several necropolises and other remains of the city, but a large unexplored area has still to be investigated. For instance, the limits of the ancient town and the presence of harbour structures are still unknown. The geophysical survey has covered an area of more than 20.000 m2 by integrating magnetic, electromagnetic, electrical and ground penetrating radar (GPR) methods. Many unseen archaeological features were clearly revealed by the interpretation of the resistivity maps and GPR time slices. A new method for the visualisation of the geophysical evidence based on VRML (Virtual Reality Markup Language) 3D data representation provides promising results to drive future excavations. The VRML shows a great potentiality for the digital visualization of the site aimed at its exploitation and usability even without the archaeological excavation.

Excavation-caused extra deformation of existing masonry residence in soft soil region

NASA Astrophysics Data System (ADS)

Tang, Y.; Franceschelli, S.

2017-04-01

Growing need for construction of infrastructures and buildings in fast urbanization process creates challenges of interaction between buildings under construction and adjacent existing buildings. This paper presents the mitigation of contradiction between two parties who are involved the interaction using civil engineering techniques. Through the in-depth analysis of the results of monitoring surveys and enhanced accuracy and reliability of surveys, a better understanding of the behavior of deformable buildings is achieved. Combination with the original construction documents, the two parties agree that both of them are responsible for building damages and a better understanding for the rehabilitation of the existing buildings is focused on. Two cases studies are used to demonstrate and describe the importance of better understanding of the behavior of existing buildings and their rehabilitations. The objective of this study is to insight into mechanisms of soil-structure interaction for buildings adjacent to deep excavations, which can result in a damage in existing masonry residence, and to take the optimized measures to make deep excavations safety and economic and adjacent buildings keep good serviceability in urban areas with soft soil conditions.

New drainage tunnel of the tunnel Višňové - design and excavation

NASA Astrophysics Data System (ADS)

Jurík, Igor; Grega, Ladislav; Valko, Jozef; Janega, Peter

2017-09-01

The actual pilot tunnel dated to the period of geological and hydrogeological survey, is designed as a part of the tunnel Višňové, which is located at the section of the D1 motorway Lietavská Lúčka - Višňové - Dubná Skala in Slovakia. Drainage tunnel will be used for the drainage of the main tunnel tubes, where the maximum inflow from the eastern portal is greater than 250 l.s-1. Overlapping of the initial pilot tunnel with the profile of the southern tunnel tube led to the demolition of the portal sections of the pilot tunnel during the excavation of main tunnel tubes. These sections were replaced by new drainage tunnels, with the lengths of 288.0 meters from west portal and 538.0 meters from eastern portal, to ensure access from both portals. The new drainage tunnel is excavated under the level of the two main tunnel tubes. Drainage pipes with a diameter of 250 mm will be installed from cleaning niches in the main tunnel tubes to the new drainage tunnel.

Characterisation of excavated fine fraction and waste composition from a Swedish landfill.

PubMed

Jani, Yahya; Kaczala, Fabio; Marchand, Charlotte; Hogland, Marika; Kriipsalu, Mait; Hogland, William; Kihl, Anders

2016-12-01

The present research studies the characterisation and the physico-chemical properties of an excavated fine fraction (<10 mm) from a Swedish landfill, the Högbytorp. The results showed that the fine fraction represents 38% by mass of the total excavated wastes and it contains mainly soil-type materials and minerals. Higher concentrations of zinc, copper, barium and chromium were found with concentrations higher than the Swedish Environmental Protection Agency (EPA) for contaminated soil. The found moisture and organic contents of the fine fraction were 23.5% and 16.6%, respectively. The analysed calorific value (1.7 MJ kg -1 ), the potential of CH 4 (4.74 m 3  t -1 dry matter) and Total Organic Carbon (TOC) (5.6%) were low and offer low potential of energy. Sieving the fine fraction further showed that 80% was smaller than 2 mm. The fine represents a major fraction at any landfill (40%-70%), therefore, characterising the properties of this fraction is essential to find the potential of reusing/recycling or safely redisposing. © The Author(s) 2016.

Corrective action plan for corrective action Unit 342: Area 23 Mercury Fire Training Pit, Nevada Test Site, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nacht, S.

1999-08-01

The Mercury Fire Training Pit is a former fire training area located in Area 23 of the Nevada Test Site (NTS). The Mercury Fire Training Pit was used from approximately 1965 to the early 1990s to train fire-fighting personnel at the NTS, and encompasses an area approximately 107 meters (m) (350 feet [ft]) by 137 m (450 ft). The Mercury Fire Training Pit formerly included a bermed burn pit with four small burn tanks, four large above ground storage tanks an overturned bus, a telephone pole storage area, and areas for burning sheds, pallets, and cables. Closure activities will includemore » excavation of the impacted soil in the aboveground storage tank and burn pit areas to a depth of 1.5 m (5 ft), and excavation of the impacted surface soil downgradient of the former ASTs and burnpit areas to a depth of 0.3 m (1 ft). Excavated soil will be disposed in the Area 6 Hydrocarbon Landfill at the NTS.« less

A STUDY ON MECHANICAL BEHAVIOR OF SUPPORT ELEMENTS INDUCED BY SHAFT SINKING

NASA Astrophysics Data System (ADS)

Tsusaka, Kimikazu; Inagaki, Daisuke; Hatsuyama, Yoshihiro; Koike, Masashi; Shimada, Tomohiro; Ijiri, Yuji

Japan Atomic Energy Agency has been excavating three deep shafts through soft sedimentary rock in the Horonobe Underground Research Laboratory. In this paper, the authors discussed change in stress and the stress distribution in a concrete lining and steel arch ribs induced by the 6.5 m diameter shaft sinking. They conducted not only field measurements of stress in support elements at a depth of around 220 m but also three-dimensional numerical analysis which models the shaft excavation procedure such as timing of installation of support elements and setting and removal of a concrete form. As a result, it was clarified that more than 10 MPa difference in circumferential stress occurred in a 2 m high and 400 mm thick concrete lining due to anisotropy of initial stress and three-dimensional effect of an excavation face. It was also found that a concrete lining gradually deformed from an original cylindrical form to a shape of an ellipsis with the long axis pallarel to the direction of the minimum horizontal principal stress after a concrete form was removed.

Soil geochemical analyses as an indication of metal working at the excavation of a house in the Roman City at Silchester (UK)

NASA Astrophysics Data System (ADS)

Cook, S. R.; Fulford, M.; Ciarke, A.; Pearson, C.

2003-05-01

Silchesteris the site of a major late Iron Age and Roman town (Calleva Atrebatum), situated in northern Hampshire (England (UK)) and occupied between the late first century BC and the fifth or sixth century AD. Extensive evidence of the nature of the buildings and the plan of the town was obtained from excavations undertaken between 1890 and 1909. The purpose of this study was to use soil geochemical analyses to reinforce the archaeological evidence particularly with reference to potential metal working at the site Soil analysis has been used previously to distinguish different functions or land use activity over a site and to aid identification and interpretation of settlement features (Entwistle et al., 2000). Samples were taken from two areas of the excavation on a l-metre grid. Firstly from an area of some 500 square metres from contexts of late first/early second century AD date throughout the entirety of a large “town house” (House 1) from which there was prima facie evidence of metalworking.

Building on Sub-Arctic Soil: Geopolymerization of Muskeg to a Densified Load-Bearing Composite.

PubMed

Waetzig, Gregory R; Cho, Junsang; Lacroix, Max; Banerjee, Sarbajit

2017-11-07

The marshy water-saturated soil typical of the sub-Arctic represents a considerable impediment to the construction of roads, thereby greatly hindering human habitation and geological excavation. Muskeg, the native water-laden topsoil characteristic of the North American sub-Arctic, represents a particularly vexing challenge for road construction. Muskeg must either be entirely excavated, or for direct construction on muskeg, a mix of partial excavation and gradual compaction with the strategic placement of filling materials must be performed. Here, we demonstrate a novel and entirely reversible geopolymerization method for reinforcing muskeg with wood fibers derived from native vegetation with the addition of inorganic silicate precursors and without the addition of extraneous metal precursors. A continuous siloxane network is formed that links together the muskeg, wood fibers, and added silicates yielding a load-bearing and low-subsidence composite. The geopolymerization approach developed here, based on catalyzed formation of a siloxane network with further incorporation of cellulose, allows for an increase of density as well as compressive strength while reducing the compressibility of the composite.

Detection of Shallow Buried Archaeological Remains Structure using 2-D Resistivity Method at Sungai Batu, Lembah Bujang, Kedah

NASA Astrophysics Data System (ADS)

Ismail, Nurina; Nordiana, M. M.; Saidin, M.; Masnan, S. S. K.; Abir, I. A.

2018-04-01

In an archaeological study, 2-D resistivity becomes important tools for the scientific investigation and also can be applied to map shallow subsurface structures at the archaeological site. The main purpose of the research is to locate the shallow buried archaeological remains structure in the area of Sungai Batu, Lembah Bujang, Kedah (Malaysia). Resistivity surveys have been applied using a Pole-dipole array with both 5 survey lines for SB1 and SB2 sites using 0.75 m electrode spacing. Both results revealed high resistivity zone with ≥ 3000 Ωm at a depth ranging from 0-1.5 m at the study area. SB1 site conducting an excavation to validate the result obtain while SB2 is not conducting any excavation. Besides that, the other characteristics of the buried archaeological remains are indicated as mound area and there is exposed remain found on top of the surface. Based on the archaeological evidence, the higher resistivity value indicates the interesting anomaly which is clay bricks for archaeological excavation.

Trade and Industry at Africa's Hub: Petrography of Pottery from Meroe, Sudan

NASA Astrophysics Data System (ADS)

Mason, R.; Grzymski, K.

2009-04-01

The ancient city of Meroë lies about 200 km northeast of Khartoum, on the Nile River. Apart from being the centre of a number of important Nubian kingdoms, such as that of the Kushites (circa 800 BCE - 350 CE), it was always a major hub for trade between ancient Egypt and the rest of Africa, and also for local production of various commodities, particularly including gold. Excavations at the site by a team from the Royal Ontario Museum (ROM) of Toronto and the University of Khartoum have continued the research of Peter Shinnie, aimed at unraveling the history of the site and its contact with Egypt and Africa (Grzymski 2003). Petrographic analysis of pottery from the ROM/Khartoum excavations and also Shinnie's excavations, also stored at the ROM, is aimed at examining the diversity of local production and raw material procurement and processing, and also identifying imported ceramics to give a better idea of the archaeologically determinable contacts of Meroë with Egypt and the rest of Africa. Reference: Grzymski, K. A., 2003, "Meroe Reports I," Society for the Study of Egyptian Antiquities Publication XVII, Toronto.

Model uncertainty of various settlement estimation methods in shallow tunnels excavation; case study: Qom subway tunnel

NASA Astrophysics Data System (ADS)

Khademian, Amir; Abdollahipour, Hamed; Bagherpour, Raheb; Faramarzi, Lohrasb

2017-10-01

In addition to the numerous planning and executive challenges, underground excavation in urban areas is always followed by certain destructive effects especially on the ground surface; ground settlement is the most important of these effects for which estimation there exist different empirical, analytical and numerical methods. Since geotechnical models are associated with considerable model uncertainty, this study characterized the model uncertainty of settlement estimation models through a systematic comparison between model predictions and past performance data derived from instrumentation. To do so, the amount of surface settlement induced by excavation of the Qom subway tunnel was estimated via empirical (Peck), analytical (Loganathan and Poulos) and numerical (FDM) methods; the resulting maximum settlement value of each model were 1.86, 2.02 and 1.52 cm, respectively. The comparison of these predicted amounts with the actual data from instrumentation was employed to specify the uncertainty of each model. The numerical model outcomes, with a relative error of 3.8%, best matched the reality and the analytical method, with a relative error of 27.8%, yielded the highest level of model uncertainty.

Septic tank burial: not just another skeleton in the closet.

PubMed

Lew, E O; Bannach, B; Rodriguez, W C

1996-09-01

Backed-up toilets lead to the discovery of a skeleton in the septic tank. Our challenges began with the excavation of this unconventional grave and progressed through recovery and examination of the skeleton, determination of the cause and manner of death, and ultimately, identification of the victim. Main aspects of the septic tank system are summarized, including functional theory, physical design and components, and general comments on use and maintenance. We discuss some basic principles applicable to the excavation and examination of any human skeletal remains, and offer a general approach to identification of the decedent.

Harry S. Truman Dam and Reservoir, Missouri, Mitigation of the Adverse Effects Upon the Local Paleontological Resources. Volume 2. Plan Maps of Excavations.

DTIC Science & Technology

1983-01-01

7 A-A147 693 HARRY S TRUMAN D’AM AND RESERVOIR MISSOURI MITIGATION OF 1/ THE ADVERSE EFFEC. .0) ILLINOIS STATE MUSEUM SOCIETY SPRINGFIELD d d...BUREAU OF STANDARDS-.1963-A 1 2 qZTM II 0A MITIGATION OF THE ADVERSE EFFECTS UPON THE LOCAL PALEONTOLOGICAL RESOURCES OF THE HARRY S. TRUMAN DAM AND...RESERVOIR OSAGE RIVER BASIN, MISSOURI FINAL REPORT OF FINDINGS VOLUME II: PLAN MAPS OF EXCAVATIONS by Jeffrey J. Saunders, Ph.D. Illinois State Museum

Construction operations for an early lunar base

NASA Technical Reports Server (NTRS)

Graf, John

1988-01-01

Six construction tasks identified as activities likely to be performed at an early lunar base are described: initializing the habitation module, preparing a landing site, transferring payload off the lander, smoothing roads, constructing the inflatable structure, and excavating for lunar oxygen production. Requirements for each task are given, and a point design capable of meeting the task requirements is described. EVA needs are listed for each task. The equipment used to perform these tasks is described. It is noted that all the tasks can be performed with three common vehicles (a rover, a truck, and an excavator) and some shared equipment.

How crawler track-mounted conveyors improve bulk handling's economics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hawkins, G.P.

1984-11-01

Crawler track-mounted conveyors can be used in most applications formerly requiring stacking, reclaiming or movement from excavators to bench conveyors. The crawler track-mounted conveyor has been automated for push button operation and allows mobilization of in-pit operations for the movement of overburden, minerals and coal. In-pit mobilization of crushers, the use of mobilized steep angle conveyor for the removal of coal from the pit, and the movement of overburden from excavation to spoil can all be done more economically when a combination of a crawler track mounted conveyor is used in conjunction with a shiftable or fixed conveyor.

Development of a Deep-Penetrating, Compact Geothermal Heat Flow System for Robotic Lunar Geophysical Missions

NASA Technical Reports Server (NTRS)

Nagihara, Seiichi; Zacny, Kris; Hedlund, Magnus; Taylor, Patrick T.

2012-01-01

Geothermal heat flow measurements are a high priority for the future lunar geophysical network missions recommended by the latest Decadal Survey of the National Academy. Geothermal heat flow is obtained as a product of two separate measurements of geothermal gradient and thermal conductivity of the regolith/soil interval penetrated by the instrument. The Apollo 15 and 17 astronauts deployed their heat flow probes down to 1.4-m and 2.3-m depths, respectively, using a rotary-percussive drill. However, recent studies show that the heat flow instrument for a lunar mission should be capable of excavating a 3-m deep hole to avoid the effect of potential long-term changes of the surface thermal environment. For a future robotic geophysical mission, a system that utilizes a rotary/percussive drill would far exceed the limited payload and power capacities of the lander/rover. Therefore, we are currently developing a more compact heat flow system that is capable of 3-m penetration. Because the grains of lunar regolith are cohesive and densely packed, the previously proposed lightweight, internal hammering systems (the so-called moles ) are not likely to achieve the desired deep penetration. The excavation system for our new heat flow instrumentation utilizes a stem which winds out of a pneumatically driven reel and pushes its conical tip into the regolith. Simultaneously, gas jets, emitted from the cone tip, loosen and blow away the soil. Lab tests have demonstrated that this proboscis system has much greater excavation capability than a mole-based heat flow system, while it weighs about the same. Thermal sensors are attached along the stem and at the tip of the penetrating cone. Thermal conductivity is measured at the cone tip with a short (1- to 1.5-cm long) needle sensor containing a resistance temperature detector (RTD) and a heater wire. When it is inserted into the soil, the heater is activated. Thermal conductivity of the soil is obtained from the rate of temperature increase during the heating. By stopping during the excavation, it is possible to measure thermal conductivities at different depths. The gas jets are turned off when the penetrating cone reaches the target depth. Then, the stem pushes the needle sensor into the undisturbed soil at the bottom of the hole and carries out a thermal conductivity measurement. When the measurement is complete, the system resumes excavation. RTDs, placed along the stem at short (approx 30 cm) intervals, will monitor long-term temperature stability of the subsurface. Temperature in the shallow subsurface would fluctuate with the diurnal, annual, and precession cycles of the Moon. These thermal waves penetrate to different depths into the regolith. Longterm monitoring of the subsurface temperature would allow us to accurately delineate these cyclic signals and separate them from the signal associated with the outward flow of the Moon s endogenic heat. Further, temperature toward bottom of the 3-m hole should be fairly stable after the heat generated during the excavation dissipates into the surrounding soil. The geothermal gradient may be determined reliably from temperature measurements at the RTDs near the bottom. In order to minimize the heat conduction along the stem from affecting the geothermal gradient measurements, we plan to use low-conductive materials for the stem and develop a mechanism to achieve close coupling between the RTDs and the wall of the excavated hole.

Pollution potential leaching index as a tool to assess water leaching risk of arsenic in excavated urban soils.

PubMed

Li, Jining; Kosugi, Tomoya; Riya, Shohei; Hashimoto, Yohey; Hou, Hong; Terada, Akihiko; Hosomi, Masaaki

2018-01-01

Leaching of hazardous trace elements from excavated urban soils during construction of cities has received considerable attention in recent years in Japan. A new concept, the pollution potential leaching index (PPLI), was applied to assess the risk of arsenic (As) leaching from excavated soils. Sequential leaching tests (SLT) with two liquid-to-solid (L/S) ratios (10 and 20Lkg -1 ) were conducted to determine the PPLI values, which represent the critical cumulative L/S ratios at which the average As concentrations in the cumulative leachates are reduced to critical values (10 or 5µgL -1 ). Two models (a logarithmic function model and an empirical two-site first-order leaching model) were compared to estimate the PPLI values. The fractionations of As before and after SLT were extracted according to a five-step sequential extraction procedure. Ten alkaline excavated soils were obtained from different construction projects in Japan. Although their total As contents were low (from 6.75 to 79.4mgkg -1 ), the As leaching was not negligible. Different L/S ratios at each step of the SLT had little influence on the cumulative As release or PPLI values. Experimentally determined PPLI values were in agreement with those from model estimations. A five-step SLT with an L/S of 10Lkg -1 at each step, combined with a logarithmic function fitting was suggested for the easy estimation of PPLI. Results of the sequential extraction procedure showed that large portions of more labile As fractions (non-specifically and specifically sorbed fractions) were removed during long-term leaching and so were small, but non-negligible, portions of strongly bound As fractions. Copyright © 2017 Elsevier Inc. All rights reserved.

Experience in design and construction of the Log tunnel

NASA Astrophysics Data System (ADS)

Jovičić, Vojkan; Goleš, Niko; Tori, Matija; Peternel, Miha; Vajović, Stanojle; Muhić, Elvir

2017-09-01

A twin highway Log tunnel is a part of a new motorway connection between Maribor and Zagreb, section Draženci-Gru\\vskovje, which is located towards the border crossing between Slovenia and Croatia. The tunnel is currently under construction, and only the excavation works have been completed during the writing of this paper. The terrain in the area of the Log tunnel is diverse, and the route of the highway in its vicinity is characterised by deep excavations, bridges or viaducts. The Log tunnel is approximately 250 m long, partly constructed as a gallery. The geological conditions are dominated by Miocene base rock, featuring layers of well-connected clastic rocks, which are covered by diluvium clays, silts, sands and gravels of different thicknesses. Due to the short length of the tunnel, the usual separation of the motorway route to the left and the right tunnel axes was not carried out. Thus, the tunnel was constructed with an intermediate pillar and was designed as a three-lane tunnel, including the stopping lane. The construction of the tunnel was carried out using the New Austrian tunnelling method (NATM), in which the central adit was excavated first and the intermediate pillar was constructed within it. The excavation of the main tubes followed and was divided into the top heading, bench and the invert, enabling the intermediate pillar to take the load off the top heading of both tubes. The secondary lining of the tunnel is currently under construction. The experience of the tunnel construction gathered so far is presented in the paper. The main emphasis is on the construction of the intermediate pillar, which had to take the significant and asymmetrical ground load.

Erosion and sediment delivery following removal of forest roads

USGS Publications Warehouse

Madej, Mary Ann

2001-01-01

Erosion control treatments were applied to abandoned logging roads in California, with the goal of reducing road-related sediment input to streams and restoring natural hydrologic patterns on the landscape. Treatment of stream crossings involved excavating culverts and associated road fill and reshaping streambanks. A variety of techniques were applied to road benches, which included decompacting the road surface, placing unstable road fill in more stable locations, and re-establishing natural surface drainage patterns. Following treatment and a 12-year recurrence-interval storm, some road reaches and excavated stream crossings showed evidence of mass movement failures, gullying, bank erosion and channel incision. Post-treatment erosion from excavated stream crossings was related to two variables: a surrogate for stream power (drainage area × channel gradient) and the volume of fill excavated from the channel. Post-treatment erosion on road reaches was related to four explanatory variables: method of treatment, hillslope position (upper, mid-slope or lower), date of treatment, and an interaction term (hillslope position × method of treatment). Sediment delivery from treated roads in upper, middle and lower hillslope positions was 10, 135 and 550 m3 of sediment per kilometre of treated roads, respectively. In contrast, inventories of almost 500 km of forest roads in adjacent catchments indicate that untreated roads produced 1500 to 4700 m3 of sediment per kilometre of road length. Erosion from 300 km of treated roads contributed less than 2 per cent of the total sediment load of Redwood Creek during the period 1978 to 1998. Although road removal treatments do not completely eliminate erosion associated with forest roads, they do substantially reduce sediment yields from abandoned logging roads.

Appraisal of operating efficiency of recharge basins on Long Island, New York, in 1969

USGS Publications Warehouse

Aronson, D.A.; Seaburn, G.E.

1974-01-01

Recharge basins on Long Island are unlined pits of various shapes and sizes excavated in surficial deposits of mainly glacial origin. Of the 2,124 recharge basins on Long Island in 1969, approximately 9 percent (194) contain water 5 or more days after a 1-inch rainfall. Basins on Long Island contain water because (1) they intersect the regional water table or a perched water table, (2) they are excavated in material of low hydraulic conductivity, (3) layers of sediment and debris of low hydraulic conductivity accumulate on the basin floor, or (4) a combination of these factors exists. Data obtained as part of this study show that (1) 22 basins contain water because they intersect the regional water table, (2) a larger percentage of the basins excavated in the Harbor Hill and the Ronkonkoma morainal deposits contain water than basins excavated in the outwash deposits, (3) a larger percentage of the basins that drain industrial and commercial areas contain water than basins that drain highways and residential areas, (4) storm runoff from commercial and industrial areas and highway: generally contains high concentrations of asphalt, grease, oil, tar, and rubber particles, whereas runoff from residential areas mainly contains leaves, grass cuttings, and other plant material, and (5) differences in composition of the soils within the drainage areas of the basins on Long Island apparently are not major factors in causing water retention. Water-containing basins dispose of an undetermined amount of storm runoff primarily by the slow infiltration of water through the bottoms and the sides of the basins. The low average specific conductance of water in most such basins suggests that evaporation does not significantly concentrate the chemical constituents and, therefore, that evaporation is not a major mechanism of water disposal from these basins.

Geoarchaeological investigations at the Winger site: A Late Paleoindian bison bonebed in Southwestern Kansas, U.S.A

USGS Publications Warehouse

Mandel, R.D.; Hofman, J.L.

2003-01-01

The Winger site is a deeply buried Late Paleoindian bison bonebed in a playa basin on the High Plains of midcontinental North America. The site is one of few stratified, Late Paleoindian bison kills recorded in the region. The bonebed is exposed in the bank of an intermittent stream that cut into the edge of the playa basin. Avocational archaeologists excavated a small portion of the exposed bonebed in the early 1970s and reported flakes in association with the skeletal remains. Limited reinvestigations of the site were undertaken in 2001, and a monthlong excavation was conducted in 2002 to assess the stratigraphy, geochronology, and archaeology. The bonebed is 35 ni long in a buried soil developed in fine-grained basin fill overlain by early Holocene alluvium (arroyo fill). Recent alluvium overlies a soil developed in the early Holocene alluvium, and modern deposits of eolian sand 2 to to < 35 cm thick mantle the site area. Artifacts found at the site include two Allen points and a flake tool discovered in the bone bed, and a biface and Allen point fragment in disturbed bonebed deposits. Excavation of 9 m2 of the bone bed revealed some fully articulated skeletons, and taphonomic observations suggest some of the bison collapsed while standing in a playa or pond margin setting. The remains of at least six bison are represented in the excavated sample from 2002, but many more animals are represented in the bonebed. A 14C age of ca. 9000 yr B.P. was determined on collagen from bison rib fragments. This age is consistent with the diagnostic artifacts found at Winger. ?? 2003 Wiley Periodicals, Inc.

Shallow magma diversions during explosive maar-diatreme eruptions in mafic volcanic fields

NASA Astrophysics Data System (ADS)

Le Corvec, N.; Muirhead, J.; White, J. D. L.

2017-12-01

Maar-diatremes are inverted conical structures formed by subterranean excavation and remobilization of country rocks during explosive volcanism and common in mafic volcanic fields. We focus on impacts of excavation and filling of maar-diatremes on the local state of stress, and its subsequent influence on underlying feeder dikes, which are critical for understanding the development of intrusive networks that feed surface eruptions. We address this issue using finite element models in COMSOL Multiphysics®. Inverted conical structures of varying sizes are excavated in a gravitationally loaded elastic half-space, and then progressively filled with volcaniclastic material, resulting in changes in the orientations and magnitudes of stresses generated within surrounding rocks and within the filling portion of the maar-diatreme. Our results show that rapid unloading during maar-diatreme excavation generates a horizontal compressive stress state beneath diatremes. These stresses allow magma to divert laterally as saucer-shaped sills and circumferential dikes at varying depths in the shallow feeder system, and produce intrusion geometries consistent with both field observations from exhumed volcanic fields and conceptual models of diatreme growth. Stresses generated in these models also provide an explanation for the evolving locations of fragmentation zones over the course of diatreme's filling. In particular, results from this study suggest that: (1) extensional stresses at the base of the diatreme fill favor magma ascent in the lower half of the structure, and possibly promote volatile exsolution and magma fragmentation; and (2) increased filling of diatremes creates a shallow compressive stress state that can inhibit magma ascent to the surface, promoting widespread intra-diatreme explosions, efficient mixing of host rock, and upward widening of the diatreme structure.

Development of Compact, Modular Lunar Heat Flow Probes

NASA Technical Reports Server (NTRS)

Nagihara, S.; Zacny, K.; Hedlund, M.; Taylor, P. T.

2014-01-01

Geothermal heat flow measurements are a high priority for the future lunar geophysical network missions recommended by the latest Decadal Survey and previously the International Lunar Network. Because the lander for such a mission will be relatively small, the heat flow instrumentation must be a low-mass and low-power system. The instrument needs to measure both thermal gradient and thermal conductivity of the regolith penetrated. It also needs to be capable of excavating a deep enough hole (approx. 3 m) to avoid the effect of potential long-term changes of the surface thermal environment. The recently developed pneumatic excavation system can largely meet the low-power, low-mass, and the depth requirements. The system utilizes a stem which winds out of a pneumatically driven reel and pushes its conical tip into the regolith. Simultaneously, gas jets, emitted from the cone tip, loosen and blow away the soil. The thermal sensors consist of resistance temperature detectors (RTDs) embedded on the stem and an insitu thermal conductivity probe attached to the cone tip. The thermal conductivity probe consists of a short 'needle' (2.4-mm diam. and 15- to 20-mm length) that contains a platinum RTD wrapped in a coil of heater wire. During a deployment, when the penetrating cone reaches a desired depth, it stops blowing gas, and the stem pushes the needle into the yet-to-be excavated, undisturbed bottom soil. Then, it begins heating and monitors the temperature. Thermal conductivity of the soil can determined from the rate of temperature increase with time. When the measurement is complete, the system resumes excavation until it reaches the next targeted depth.

Strain corrosion cracking in rpm sewer piping

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hopkins, S.W.; Wachob, H.F.; Duffner, D.H.

1993-12-31

Long term, aggressive environmental exposure can result in localized failure of large diameter, glass reinforced plastic mortar (RPM) piping. In order to evaluate the performance of the liner and glass reinforced matrix polyester resin, accelerated strain corrosion tests were performed on samples of RPM piping that had already experienced almost 15 years of service. To assess the sensitivity of RPM pipe to acidic environments and to correlate the fractography of the laboratory produced failures with the excavated crack, short segments of 8-inch and 48-inch diameter piping were statically loaded to produce various known surface strains. After preloading the specimens tomore » fixed strain levels, these samples were then exposed to sulfuric acid solutions having pH values of 2.7 and 4.7 and monitored as a function of time until failure. The resulting lifetimes were related to initial surface strains and showed a decreasing logarithmic relationship. Fractographic examination of the excavated crack revealed the typical strain corrosion fractography of glass fibers after almost a 1000 hour exposure at 1.3 % strain; similar fractographic observations were obtained from failed laboratory samples. At shorter times, failure appeared to be overload in nature and exhibited little, if any, timedependent fracture features. Fractographic examination of the excavated crack strongly indicated that the crack had been present for a significant time. The extremely aggressive environment had totally dissolved the exposed glass reinforcement. Based on the laboratory strain corrosion performance, the nature of the contained cracking, and fractography of the failed surface, cracking of the excavated RPM pipe was believed to be the result of an early overload failure that subsequently propagated slowly via strain corrosion in an extremely aggressive environment.« less

A low cost, high performance remotely controlled backhoe/excavator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rizzo, J.

1995-12-31

This paper addresses a state of the art, low cost, remotely controlled backhoe/excavator system for remediation use at hazardous waste sites. The all weather, all terrain, Remote Dig-It is based on a simple, proven construction platform and incorporates state of the art sensors, control, telemetry and other subsystems derived from advanced underwater remotely operated vehicle systems. The system can be towed to a site without the use of a trailer, manually operated by an on board operator or operated via a fiber optic or optional RF communications link by a remotely positioned operator. A proportional control system is piggy backedmore » onto the standard manual control system. The control system improves manual operation, allows rapid manual/remote mode selection and provides fine manual or remote control of all functions. The system incorporates up to 4 separate video links, acoustic obstacle proximity sensors, and stereo audio pickups and an optional differential GPS navigation. Video system options include electronic panning and tilting within a distortion-corrected wide angle field of view. The backhoe/excavator subsystem has a quick disconnect interface feature which allows its use as a manipulator with a wide variety of end effectors and tools. The Remote Dig-It was developed to respond to the need for a low-cost, effective remediation system for use at sites containing hazardous materials. The prototype system was independently evaluated for this purpose by the Army at the Jefferson Proving Ground where it surpassed all performance goals. At the time of this writing, the Remote Dig-It system is currently the only backhoe/excavator which met the Army`s goals for remediation systems for use at hazardous waste sites and it costs a fraction of any known competing offerings.« less

Improved Geologic Interpretation of Non-invasive Electrical Resistivity Imaging from In-situ Samples

NASA Astrophysics Data System (ADS)

Mucelli, A.; Aborn, L.; Jacob, R.; Malusis, M.; Evans, J.

2016-12-01

Non-invasive geophysical techniques are useful in characterizing the subsurface geology without disturbing the environment, however, the ability to interpret the subsurface is enhanced by invasive work. Since geologic materials have electrical resistivity values it allows for a geologic interpretation to be made based on variations of electrical resistivity measured by electrical resistivity imaging (ERI). This study focuses on the pre-characterization of the geologic subsurface from ERI collected adjacent to the Montandon Marsh, a wetland located near Lewisburg, PA within the West Branch of the Susquehanna River watershed. The previous invasive data, boreholes, indicate that the subsurface consists of limestone and shale bedrock overlain with sand and gravel deposits from glacial outwash and aeolian processes. The objective is to improve our understanding of the subsurface at this long-term hydrologic research site by using excavation results, specifically observed variations in geologic materials and electrical resistivity laboratory testing of subsurface samples. The pre-excavation ERI indicated that the shallow-most geologic material had a resistivity value of 100-500 ohm-m. In comparison, the laboratory testing indicated the shallow-most material had the same range of electrical resistivity values depending on saturation levels. The ERI also showed that there was an electrically conductive material, 7 to 70 ohm-m, that was interpreted to be clay and agreed with borehole data, however, the excavation revealed that at this depth range the geologic material varied from stratified clay to clay with cobbles to weathered residual clay. Excavation revealed that the subtle variations in the electrical conductive material corresponded well with the variations in the geologic material. We will use these results to reinterpret previously collected ERI data from the entire long-term research site.

Coal Thickness Gauging Using Elastic Waves

NASA Technical Reports Server (NTRS)

Nazarian, Soheil; Bar-Cohen, Yoseph

1999-01-01

The efforts of a mining crew can be optimized, if the thickness of the coal layers to be excavated is known before excavation. Wave propagation techniques can be used to estimate the thickness of the layer based on the contrast in the wave velocity between coal and rock beyond it. Another advantage of repeated wave measurement is that the state of the stress within the mine can be estimated. The state of the stress can be used in many safety-related decisions made during the operation of the mine. Given these two advantages, a study was carried out to determine the feasibility of the methodology. The results are presented herein.

Working Performance Analysis of Rolling Bearings Used in Mining Electric Excavator Crowd Reducer

NASA Astrophysics Data System (ADS)

Zhang, Y. H.; Hou, G.; Chen, G.; Liang, J. F.; Zheng, Y. M.

2017-12-01

Refer to the statistical load data of digging process, on the basis of simulation analysis of crowd reducer system dynamics, the working performance simulation analysis of rolling bearings used in crowd reducer of large mining electric excavator is completed. The contents of simulation analysis include analysis of internal load distribution, rolling elements contact stresses and rolling bearing fatigue life. The internal load characteristics of rolling elements in cylindrical roller bearings are obtained. The results of this study identified that all rolling bearings satisfy the requirements of contact strength and fatigue life. The rationality of bearings selection and arrangement is also verified.

[Influence of work intensity on development of arterial hypertension in metal-mining workers].

PubMed

Ustinova, O Iu; Alekseev, V B; Rumiantseva, A N; Orehova, Ia V

2013-01-01

The article covers data on influence of working shifts duration and shift work intensity on cardiovascular system functioning in operators of mining excavators. Findings are that 8 hours shift with regular shift schedule (40 working hours per week) gives significant load on cardiovascular system of workers engaged into underground activities. 50% of mining excavator operators following this working schedule develop transitory arterial hypertension within 10 years. Longer work shift over 8 hours and more intensive shifting schedule over 40 hours per week causes stable arterial hypertension within 3 months in 60% of workers, in 10% of cases associated with lower functioning of sinus node.

Zero Horizontal Reaction Force Excavator

NASA Technical Reports Server (NTRS)

Mueller, Robert P. (Inventor); Nick, Andrew J. (Inventor); Schuler, Jason M. (Inventor); Smith, Jonathan D. (Inventor)

2015-01-01

An excavator includes a mobile chassis with a first bucket drum and a second bucket drum coupled thereto. The first bucket drum and second bucket drum are coupled to the chassis for positioning thereof on the surface at opposing ends of the chassis. Each first scoop on the first bucket drum is a mirror image of one second scoop on the second bucket drum when (i) the first bucket drum and second bucket drum are on the surface adjacent opposing ends of the chassis, and (ii) the first bucket drum is rotated in one direction and the second bucket drum is simultaneously rotated in an opposing direction.

Deep Impact: excavating comet Tempel 1.

PubMed

A'Hearn, M F; Belton, M J S; Delamere, W A; Kissel, J; Klaasen, K P; McFadden, L A; Meech, K J; Melosh, H J; Schultz, P H; Sunshine, J M; Thomas, P C; Veverka, J; Yeomans, D K; Baca, M W; Busko, I; Crockett, C J; Collins, S M; Desnoyer, M; Eberhardy, C A; Ernst, C M; Farnham, T L; Feaga, L; Groussin, O; Hampton, D; Ipatov, S I; Li, J-Y; Lindler, D; Lisse, C M; Mastrodemos, N; Owen, W M; Richardson, J E; Wellnitz, D D; White, R L

2005-10-14

Deep Impact collided with comet Tempel 1, excavating a crater controlled by gravity. The comet's outer layer is composed of 1- to 100-micrometer fine particles with negligible strength (<65 pascals). Local gravitational field and average nucleus density (600 kilograms per cubic meter) are estimated from ejecta fallback. Initial ejecta were hot (>1000 kelvins). A large increase in organic material occurred during and after the event, with smaller changes in carbon dioxide relative to water. On approach, the spacecraft observed frequent natural outbursts, a mean radius of 3.0 +/- 0.1 kilometers, smooth and rough terrain, scarps, and impact craters. A thermal map indicates a surface in equilibrium with sunlight.

The Bank of Westminster and Hyland Park Construction Contracts as Engineering Student Classroom Projects; Construction Phase.

DTIC Science & Technology

1984-12-13

8217-- - - -- - - - - - ----- - - - - - - - .101 Clear at Building Clear&Grub @ Bldg. 2000.00 CY .50 1,0(,() Mass Bldg. Excav. 26000.00 CY 2.50 65.00, Grade Beam Excav. 2100.00 CY 4.00...95,112 Sail Investigation Compaction Tests 20.00 EA 150.00 3.000 Perimeter Drainage 2000.00 LF 16.00 32,00 Under Floor Drain LF Clean Walks /Street 1.00 LS...EA4 Equip. Curbs 3500.00 Sf 5.00 17.5:00 -. Grade Beams 7200.00 SF 11.50 82,800 Sumo Pits 1.00 EA 500.00 500 Cooling Tower Sump 600.00 SF 11.50 6,900

Investigations of the historic textiles excavated from Ancient Ainos (Enez - Turkey) by multiple analytical techniques

NASA Astrophysics Data System (ADS)

Akyuz, Sevim; Akyuz, Tanil; Cakan, Banu; Basaran, Sait

2014-09-01

Some metal ornamented textile specimens and a textile button, excavated from Ancient Ainos (Enez - Turkey), have been investigated using FTIR and EDXRF spectrometry, for the purpose of material identification. FTIR spectral results indicated that textiles were made from partially degummed Bombyx mori silk. The IR spectral investigation of the textile button revealed that some cellulose fillings were used inside the button. The EDXRF analysis of the metal ornaments showed that they were silver plated copper. Surface morphology of the textiles and the metal ornaments were investigated by SEM images. It was shown that textile fibers were highly degraded.

Investigation of Key Parameters of Rock Cracking Using the Expansion of Vermiculite Materials

PubMed Central

Ahn, Chi-Hyung; Hu, Jong Wan

2015-01-01

The demand for the development of underground spaces has been sharply increased in lieu of saturated ground spaces because the residents of cities have steadily increased since the 1980s. The traditional widely used excavation methods (i.e., explosion and shield) have caused many problems, such as noise, vibration, extended schedule, and increased costs. The vibration-free (and explosion-free) excavation method has currently attracted attention in the construction site because of the advantage of definitively solving these issues. For such reason, a new excavation method that utilizes the expansion of vermiculite with relatively fewer defects is proposed in this study. In general, vermiculite materials are rapidly expanded in volume when they receive thermal energy. Expansion pressure can be produced by thermal expansion of vermiculite in a steel tube, and measured by laboratory tests. The experimental tests are performed with various influencing parameters in an effort to seek the optimal condition to effectively increase expansion pressure at the same temperature. Then, calibrated expansion pressure is estimated, and compared to each model. After analyzing test results for expansion pressure, it is verified that vermiculite expanded by heat can provide enough internal pressure to break hard rock during tunneling work. PMID:28793610

Bioturbation by the Fungus-Gardening Ant, Trachymyrmex septentrionalis

PubMed Central

Tschinkel, Walter R.; Seal, Jon N.

2016-01-01

Soil invertebrates such as ants are thought to be important manipulators of soils in temperate and tropical ecosystems. The fungus gardening ant, Trachymyrmex septentrionalis, is an important agent of biomantling, that is, of depositing soil excavated from below onto the surface, and has been suggested as an agent of bioturbation (moving soil below ground) as well. The amount of bioturbation by this ant was quantified by planting queenright colonies in sand columns consisting of 5 layers of different colored sand. The amount of each color of sand deposited on the surface was determined from April to November 2015. In November, colonies were excavated and the color and amount of sand deposited below ground (mostly as backfill in chambers) was determined. Extrapolated to one ha, T. septentrionalis deposited 800 kg of sand per annum on the surface, and an additional 200 kg (17% of the total excavated) below ground. On average, this mixes 1.3% of the sand from other layers within the top meter of soil per millennium, but this mixing is unlikely to be homogeneous, and probably occurs as "hotspots" in both horizontal and vertical space. Such mixing is discussed as a challenge to sediment dating by optically stimulated luminescence (OSL). PMID:27391485

Investigation of Key Parameters of Rock Cracking Using the Expansion of Vermiculite Materia.

PubMed

Ahn, Chi-Hyung; Hu, Jong Wan

2015-10-12

The demand for the development of underground spaces has been sharply increased in lieu of saturated ground spaces because the residents of cities have steadily increased since the 1980s. The traditional widely used excavation methods ( i.e ., explosion and shield) have caused many problems, such as noise, vibration, extended schedule, and increased costs. The vibration-free (and explosion-free) excavation method has currently attracted attention in the construction site because of the advantage of definitively solving these issues. For such reason, a new excavation method that utilizes the expansion of vermiculite with relatively fewer defects is proposed in this study. In general, vermiculite materials are rapidly expanded in volume when they receive thermal energy. Expansion pressure can be produced by thermal expansion of vermiculite in a steel tube, and measured by laboratory tests. The experimental tests are performed with various influencing parameters in an effort to seek the optimal condition to effectively increase expansion pressure at the same temperature. Then, calibrated expansion pressure is estimated, and compared to each model. After analyzing test results for expansion pressure, it is verified that vermiculite expanded by heat can provide enough internal pressure to break hard rock during tunneling work.

The gravitational potential energy regeneration system with closed-circuit of boom of hydraulic excavator

NASA Astrophysics Data System (ADS)

Chen, Mingdong; Zhao, Dingxuan

2017-01-01

Considering the disadvantage of higher throttling loss for the open-circuit hydrostatic transmission at present, a novel gravitational potential energy regeneration system (GPERS) of the boom of hydraulic excavator, namely the closed-circuit GPERS, is proposed in this paper. The closed-circuit GPERS is based on a closed-circuit hydrostatic transmission and adopts a hydraulic accumulator as main energy storage element fabricated in novel configuration to recover the entire gravitational potential energy of the boom of hydraulic excavator. The matching parameter and control system design are carried out for the proposed system, and the system is modeled based on its physical attributes. Simulation and experiments are performed to validate the employed mathematical models, and then, the velocity and the pressure performance of system are analyzed. It is observed that the closed-circuit GPERS shows better velocity control of the boom and response characteristics. After that, the average working efficiency of the closed-circuit GPERS of boom is estimated under different load conditions. The results indicate that the proposed system is highly effective and that the average working efficiency in different load conditions varied from 60% to 68.2% for the experiment platform.

Model test of anchoring effect on zonal disintegration in deep surrounding rock masses.

PubMed

Chen, Xu-Guang; Zhang, Qiang-Yong; Wang, Yuan; Liu, De-Jun; Zhang, Ning

2013-01-01

The deep rock masses show a different mechanical behavior compared with the shallow rock masses. They are classified into alternating fractured and intact zones during the excavation, which is known as zonal disintegration. Such phenomenon is a great disaster and will induce the different excavation and anchoring methodology. In this study, a 3D geomechanics model test was conducted to research the anchoring effect of zonal disintegration. The model was constructed with anchoring in a half and nonanchoring in the other half, to compare with each other. The optical extensometer and optical sensor were adopted to measure the displacement and strain changing law in the model test. The displacement laws of the deep surrounding rocks were obtained and found to be nonmonotonic versus the distance to the periphery. Zonal disintegration occurs in the area without anchoring and did not occur in the model under anchoring condition. By contrasting the phenomenon, the anchor effect of restraining zonal disintegration was revealed. And the formation condition of zonal disintegration was decided. In the procedure of tunnel excavation, the anchor strain was found to be alternation in tension and compression. It indicates that anchor will show the nonmonotonic law during suppressing the zonal disintegration.

In Situ Observation of Rock Spalling in the Deep Tunnels of the China Jinping Underground Laboratory (2400 m Depth)

NASA Astrophysics Data System (ADS)

Feng, Xia-Ting; Xu, Hong; Qiu, Shi-Li; Li, Shao-Jun; Yang, Cheng-Xiang; Guo, Hao-Sen; Cheng, Yuan; Gao, Yao-Hui

2018-04-01

To study rock spalling in deep tunnels at China Jinping Underground Laboratory Phase II (CJPL-II), photogrammetry method and digital borehole camera were used to quantify key features of rock spalling including orientation, thickness of slabs and the depth of spalling. The failure mechanism was analysed through scanning electron microscope and numerical simulation based on FLAC3D. Observation results clearly showed the process of rock spalling failure: a typical spalling pattern around D-shaped tunnels after top-heading and bottom bench were discovered. The orientation and thickness of the slabs were obtained. The slabs were parallel to the excavated surfaces of the tunnel and were related to the shape of the tunnel surface and orientation of the principal stress. The slabs were alternately thick and thin, and they gradually increased in thickness from the sidewall inwards. The form and mechanism of spalling at different locations in the tunnels, as influenced by stress state and excavation, were analysed. The result of this study was helpful to those rethinking the engineering design, including the excavation and support of tunnels, or caverns, at high risk of spalling.

The numerical simulation on the stability of steep rock slope by DDA

NASA Astrophysics Data System (ADS)

Zhu, Jianye; Xue, Yiguo; Tao, Yufan; Zhang, Kai; Li, Zhiqiang; Zhang, Xuedong; Yang, Ying

2017-05-01

China is a mountainous country, especially in the southwest area. Recently, the variety of geological disasters such as landslides caused by roadway excavation has become a growing concern for our society. Blindly pursuing mining interests without regard for either the environment or residents in the surrounding areas has created a dangerous situation. In recent years, frequent collapses have occurred at Zengzi Rock in Chongqing, especially after torrential rains [1]. This landslide site is a typical example of collapse caused by mine roadway excavations. To study the mechanism of mining slope stability, we conducted a numerical simulation by DDA based on Zengzi Rock in Chongqing, China. The numerical simulation analyzes the slopes under different engineering conditions and rainfall conditions. The results show that the slope has already been changed under the action of its own joints and fissures. After the excavation of the roadway and the rainfall action, this change is drastically increased and the effect is obvious. Through the result graph, we can find that the change of the displacement and stress distribution is obvious, and the simulation results can be great significance to the mining and support of similar mountain conditions.

China action of "Cleanup Plan for Polychlorinated Biphenyls Burial Sites": emissions during excavation and thermal desorption of a capacitor-burial site.

PubMed

Yang, Bing; Zhou, Lingli; Xue, Nandong; Li, Fasheng; Wu, Guanglong; Ding, Qiong; Yan, Yunzhong; Liu, Bo

2013-10-01

Scarce data are available so far on emissions in a given scenario for excavation and thermal desorption, a common practice, of soils contaminated with polychlorinated biphenyls (PCBs). As part of China action of "Cleanup Plan for PCBs Burial Sites", this study roughly estimated PCBs emissions in the scenario for a capacitor-burial site. The concentrations of total PCBs (22 congeners) in soils were in the range of 2.1-16,000μg/g with a mean of 2300μg/g, among the same order of magnitude as the highest values obtained in various PCBs-contaminated sites. Only six congeners belonging to Di-, Tri-, and Tetra-CBs were observed above limits of detection in air samples in the scenario, partially which can be estimated by the USEPA air emission model. Comparing concentrations and composition profiles of PCBs in the soil and air samples further indicated a leaked source of commercial PCBs formulations of trichlorobiphenyl (China PCB no. 1). The measures taken if any to mitigate the volatilization and movement of PCBs and to minimize worker exposure were discussed for improvements of the excavation practice. Copyright © 2013 Elsevier Inc. All rights reserved.

Environmental impacts of remediation of a trichloroethene-contaminated site: life cycle assessment of remediation alternatives.

PubMed

Lemming, Gitte; Hauschild, Michael Z; Chambon, Julie; Binning, Philip J; Bulle, Cécile; Margni, Manuele; Bjerg, Poul L

2010-12-01

The environmental impacts of remediation of a chloroethene-contaminated site were evaluated using life cycle assessment (LCA). The compared remediation options are (i) in situ bioremediation by enhanced reductive dechlorination (ERD), (ii) in situ thermal desorption (ISTD), and (iii) excavation of the contaminated soil followed by off-site treatment and disposal. The results showed that choosing the ERD option will reduce the life-cycle impacts of remediation remarkably compared to choosing either ISTD or excavation, which are more energy-demanding. In addition to the secondary impacts of remediation, this study includes assessment of local toxic impacts (the primary impact) related to the on-site contaminant leaching to groundwater and subsequent human exposure via drinking water. The primary human toxic impacts were high for ERD due to the formation and leaching of chlorinated degradation products, especially vinyl chloride during remediation. However, the secondary human toxic impacts of ISTD and excavation are likely to be even higher, particularly due to upstream impacts from steel production. The newly launched model, USEtox, was applied for characterization of primary and secondary toxic impacts and combined with a site-dependent fate model of the leaching of chlorinated ethenes from the fractured clay till site.

Model Test of Anchoring Effect on Zonal Disintegration in Deep Surrounding Rock Masses

PubMed Central

Chen, Xu-Guang; Zhang, Qiang-Yong; Wang, Yuan; Liu, De-Jun; Zhang, Ning

2013-01-01

The deep rock masses show a different mechanical behavior compared with the shallow rock masses. They are classified into alternating fractured and intact zones during the excavation, which is known as zonal disintegration. Such phenomenon is a great disaster and will induce the different excavation and anchoring methodology. In this study, a 3D geomechanics model test was conducted to research the anchoring effect of zonal disintegration. The model was constructed with anchoring in a half and nonanchoring in the other half, to compare with each other. The optical extensometer and optical sensor were adopted to measure the displacement and strain changing law in the model test. The displacement laws of the deep surrounding rocks were obtained and found to be nonmonotonic versus the distance to the periphery. Zonal disintegration occurs in the area without anchoring and did not occur in the model under anchoring condition. By contrasting the phenomenon, the anchor effect of restraining zonal disintegration was revealed. And the formation condition of zonal disintegration was decided. In the procedure of tunnel excavation, the anchor strain was found to be alternation in tension and compression. It indicates that anchor will show the nonmonotonic law during suppressing the zonal disintegration. PMID:23997683

How to estimate green house gas (GHG) emissions from an excavator by using CAT's performance chart

NASA Astrophysics Data System (ADS)

Hajji, Apif M.; Lewis, Michael P.

2017-09-01

Construction equipment activities are a major part of many infrastructure projects. This type of equipment typically releases large quantities of green house gas (GHG) emissions. GHG emissions may come from fuel consumption. Furthermore, equipment productivity affects the fuel consumption. Thus, an estimating tool based on the construction equipment productivity rate is able to accurately assess the GHG emissions resulted from the equipment activities. This paper proposes a methodology to estimate the environmental impact for a common construction activity. This paper delivers sensitivity analysis and a case study for an excavator based on trench excavation activity. The methodology delivered in this study can be applied to a stand-alone model, or a module that is integrated with other emissions estimators. The GHG emissions are highly correlated to diesel fuel use, which is approximately 10.15 kilograms (kg) of CO2 per gallon of diesel fuel. The results showed that the productivity rate model as the result from multiple regression analysis can be used as the basis for estimating GHG emissions, and also as the framework for developing emissions footprint and understanding the environmental impact from construction equipment activities introduction.

Early (300−100 B.C.) temple precinct in the Valley of Oaxaca, Mexico

PubMed Central

Redmond, Elsa M.; Spencer, Charles S.

2013-01-01

Archaeological investigations during the past two decades in Mexico’s Valley of Oaxaca have documented the appearance of key public buildings, such as the royal palace and multiroom temple, associated with the rise of an archaic state at ca. 300−100 B.C. A fuller picture is now emerging from the site of El Palenque, where recent excavations have defined a temple precinct on the east side of the site’s plaza. This precinct exhibits characteristics similar to those of the temple precincts of later Mesoamerican states described by Colonial period sources. The excavation data document a walled enclosure containing three multiroom temples, two special residences identified as priests’ residences, and an array of ritual features and activity areas. The temple precinct’s components are interpreted as comprising a hierarchy of temples staffed by a specialized priesthood. A series of radiocarbon dates indicate that the precinct’s differentiated components were all in use during the 300−100 B.C. period of archaic state emergence. The El Palenque temple precinct is the earliest temple precinct excavated thus far in the Valley of Oaxaca. PMID:23610387

Photomosaics and event evidence from the Frazier Mountain paleoseismic site, trench 1, cuts 1–4, San Andreas Fault Zone, southern California (2007–2009)

USGS Publications Warehouse

Scharer, Katherine M.; Fumal, Tom E.; Weldon, Ray J.; Streig, Ashley R.

2014-01-01

The Frazier Mountain paleoseismic site is located at the northwest end of the Mojave section of the San Andreas Fault, in a small, closed depression at the base of Frazier Mountain near Tejon Pass, California (lat 34.8122° N., long 118.9034° W.). The site was known to contain a good record of earthquakes due to previous excavations by Lindvall and others (2002). This report provides data resulting from four nested excavations, or cuts, along trench 1 (T1) in 2007 and 2009 at the Frazier Mountain site. The four cuts were excavated progressively deeper and wider in an orientation perpendicular to the San Andreas Fault, exposing distal fan and marsh sediments deposited since ca. A.D. 1200. The results of the trenching show that earthquakes that ruptured the site have repeatedly produced a small depression or sag on the surface, which is subsequently infilled with sand and silt deposits. This report provides high-resolution photomosaics and logs for the T1 cuts, a detailed stratigraphic column for the deposits, and a table summarizing all of the evidence for ground rupturing paleoearthquakes logged in the trenches.

Method for explosive expansion toward horizontal free faces for forming an in situ oil shale retort

DOEpatents

Ricketts, Thomas E.

1980-01-01

Formation is excavated from within a retort site in formation containing oil shale for forming a plurality of vertically spaced apart voids extending horizontally across different levels of the retort site, leaving a separate zone of unfragmented formation between each pair of adjacent voids. Explosive is placed in each zone, and such explosive is detonated in a single round for forming an in situ retort containing a fragmented permeable mass of formation particles containing oil shale. The same amount of formation is explosively expanded upwardly and downwardly toward each void. A horizontal void excavated at a production level has a smaller horizontal cross-sectional area than a void excavated at a lower level of the retort site immediately above the production level void. Explosive in a first group of vertical blast holes is detonated for explosively expanding formation downwardly toward the lower void, and explosive in a second group of vertical blast holes is detonated in the same round for explosively expanding formation upwardly toward the lower void and downwardly toward the production level void for forming a generally T-shaped bottom of the fragmented mass.