Validation and implementation of bridge design specifications for barge impact loading.

DOT National Transportation Integrated Search

2014-07-01

Since 1991 in the United States, the design of highway bridges to resist collisions by errant waterway vessels has been carried out : in accordance with design provisions published by AASHTO. These provisions have remained largely unchanged for more ...

Managing Florida's fracture critical bridges - phases 1 and 2 : final report.

DOT National Transportation Integrated Search

2016-05-01

Based on the definition given in the AASHTO LRFD Bridge Design Specifications, twin steel box-girder bridges are : classified as bridges with fracture critical members (FCMs), in which a failure of a tension member is expected to : lead to a collapse...

Synthesis and evaluation of lightweight concrete research relevant to the AASHTO LRFD bridge design specifications : identification of articles for further evaluation and potential revision.

DOT National Transportation Integrated Search

2012-11-01

Much of the fundamental basis for the current lightweight concrete provisions in the AASHTO LRFD Bridge : Design Specifications is based on research of lightweight concrete (LWC) from the 1960s. The LWC that was : part of this research used tradition...

Validation and implementation of bridge design specifications for barge impact loading : [summary].

DOT National Transportation Integrated Search

2014-07-01

With the amount of water-borne traffic and the number of bridges in Florida, collisions between vessels and bridges are inevitable. Few are as devastating as the 1980 collision of a freighter with the Sunshine Skyway Bridge, which took 35 lives and e...

An Experimental Study of Elastomeric Bridge Bearings with Design Recommendations

DOT National Transportation Integrated Search

1995-10-01

Recent AASHTO specifications have placed a number of restrictions on the use of elastomeric bridge bearings. Elastomeric bearings with tapers built in to accommodate span end elevation differences were disallowed by the most current specifications ev...

Field measurements on skewed semi-integral bridge with elastic inclusion : instrumentation report.

DOT National Transportation Integrated Search

2006-01-01

This project was designed to enhance the Virginia Department of Transportation's expertise in the design of integral bridges, particularly as it applies to highly skewed structures. Specifically, the project involves extensive monitoring of a semi-in...

Field Testing and Load Rating Report for Bridge No. 4, Hybrid Composite Beam Span, at Fort Knox, Kentucky

DTIC Science & Technology

2016-09-01

required load rating (HL-93) and performance criteria for deflection and strain. Results showed the bridge met all design specifications and load...their respective owners. The findings of this report are not to be construed as an official Department of the Army position unless so designated by...composite beams met design specifications and could deliver safe crossing of Heavy Equipment Transport System (HETS-115) vehicles. Their report

Railing systems for use on timber deck bridges

Treesearch

Ronald K. Faller; Michael A. Ritter; Barry T. Rosson; Sheila R. Duwadi

1999-01-01

Bridge railing systems in the United States have historically been designed based on static load criteria given in the AASHTO Standard Specifications for Highway Bridges. In the past decade, full-scale vehicle crash testing has been recognized as a more appropriate and reliable method of evaluating bridge railing acceptability. In 1989. AASHTO published the Guide...

Analytical investigation of bidirectional ductile diaphragms in multi-span bridges

NASA Astrophysics Data System (ADS)

Wei, Xiaone; Bruneau, Michel

2018-04-01

In the AASHTO Guide Specifications for Seismic Bridge Design Provisions, ductile diaphragms are identified as Permissible Earthquake-Resisting Elements (EREs), designed to help resist seismic loads applied in the transverse direction of bridges. When adding longitudinal ductile diaphragms, a bidirectional ductile diaphragm system is created that can address seismic excitations acting along both the bridge's longitudinal and transverse axes. This paper investigates bidirectional ductile diaphragms with Buckling Restrained Braces (BRBs) in straight multi-span bridge with simply supported floating spans. The flexibility of the substructures in the transverse and longitudinal direction of the bridge is considered. Design procedures for the bidirectional ductile diaphragms are first proposed. An analytical model of the example bridge with bidirectional ductile diaphragms, designed based on the proposed methodology, is then built in SAP2000. Pushover and nonlinear time history analyses are performed on the bridge model, and corresponding results are presented. The effect of changing the longitudinal stiffness of the bidirectional ductile diaphragms in the end spans connecting to the abutment is also investigated, in order to better understand the impact on the bridge's dynamic performance.

Implementation of a localized roughness specification for use on Louisiana bridges : research project capsule : technology transfer program.

DOT National Transportation Integrated Search

2016-10-01

The Louisiana Transportation Research Center has worked closely with the Bridge : Design section of the Louisiana Department of Transportation and Development : (DOTD) to develop a workable specification for standard and localized roughness : of brid...

Seismic Design Considerations : Volume I, Technical Approaches and Results; Volume II, Appendices II-VIII

DOT National Transportation Integrated Search

2012-03-01

NJDOT has adopted AASHTO Guide Specifications for LRFD Seismic Bridge Design approved by the Highway : Subcommittee on Bridges and Structures in 2007. The main objective of research presented in this report has : been to resolve following issue...

Development of Secondary Route Bridge Design Plan Guides

DOT National Transportation Integrated Search

2018-03-03

The objective of this study is to develop a set of bridge plan guides for low-volume traffic roads. The purpose of the plans is to facilitate construction of new structures suitable for local agencies. The designs are to specifically address common l...

Performance and capacity assessment of reinforced concrete bridge piers considering the current load and resistance factor design provisions and plastic hinge length in Kansas.

DOT National Transportation Integrated Search

2014-05-01

Kansas Department of Transportation (KDOT) has implemented the new AASHTO-LRFD provisions in the state specific : LRFD design procedure (KDOT LRFD). Most of the existing bridges constructed before the new provisions, have been designed : based on the...

Feasibility of tubular fender units for pier protection against vessel collision.

DOT National Transportation Integrated Search

2008-08-01

Vessel collisions with bridges are increasing at an alarming rate, as heavy vessels are making more frequent trips under more bridges. In the US, rigorous design of bridges for vessel collision was first incorporated by AASHTO Guide Specification and...

High Strength Reinforcing Steel Bars : Concrete Shear Friction Interface : final report : Part A.

DOT National Transportation Integrated Search

2017-03-01

High-strength steel (HSS) reinforcement, specifically ASTM A706 Grade 80 (550), is now permitted by the AASHTO LRFD Bridge Design Specifications for use in reinforced concrete bridge components in non-seismic regions. Using Grade 80 (550) steel reinf...

High strength reinforcing steel bars : concrete shear friction interface : final report : Part A.

DOT National Transportation Integrated Search

2017-03-01

High-strength steel (HSS) reinforcement, specifically ASTM A706 Grade 80 (550), is now permitted by the AASHTO LRFD Bridge Design Specifications for use in reinforced concrete bridge components in non-seismic regions. Using Grade 80 (550) steel reinf...

High strength reinforcing steel bars : low cycle fatigue behavior : final report - part B.

DOT National Transportation Integrated Search

2017-03-01

High-strength steel (HSS) reinforcing steel, specifically ASTM A706 Grade 80 (550), is now permitted by the AASHTO LRFD Bridge Design Specifications for use in reinforced concrete bridge components in non-seismic regions. Using Grade 80 (550) reinfor...

High strength reinforcing steel bars : low-cycle fatigue behavior : final report - part B.

DOT National Transportation Integrated Search

2017-03-01

High-strength steel (HSS) reinforcing steel, specifically ASTM A706 Grade 80 (550), is now permitted by the AASHTO LRFD Bridge Design Specifications for use in reinforced concrete bridge components in non-seismic regions. Using Grade 80 (550) reinfor...

Statistical analysis of weigh-in-motion data for bridge design in Vermont.

DOT National Transportation Integrated Search

2014-10-01

This study investigates the suitability of the HL-93 live load model recommended by AASHTO LRFD Specifications : for its use in the analysis and design of bridges in Vermont. The method of approach consists in performing a : statistical analysis of w...

Experimental evaluation and design of unfilled and concrete-filled FRP composite piles : Task 4A : design specifications.

DOT National Transportation Integrated Search

2015-08-01

The overall goal of this project is the experimental evaluation and design of unfilled and concrete-filled FRP composite piles for load-bearing in bridges. This report covers Task 4A, Design Specifications. : Structural design specifications are base...

The impact of the AASHTO LRFD design code on bridge stiffness and strength : Part 1 : methods and design comparisons.

DOT National Transportation Integrated Search

2007-01-01

The Commonwealth of Virginia is currently transitioning from the long-used AASHTO Allowable Stress Design (ASD) specification to AASHTO's Load and Resistance Factor Design (LRFD) specification. The new specification features revised live loads, more ...

Foot force models of crowd dynamics on a wobbly bridge

PubMed Central

Belykh, Igor; Jeter, Russell; Belykh, Vladimir

2017-01-01

Modern pedestrian and suspension bridges are designed using industry standard packages, yet disastrous resonant vibrations are observed, necessitating multimillion dollar repairs. Recent examples include pedestrian-induced vibrations during the opening of the Solférino Bridge in Paris in 1999 and the increased bouncing of the Squibb Park Bridge in Brooklyn in 2014. The most prominent example of an unstable lively bridge is the London Millennium Bridge, which started wobbling as a result of pedestrian-bridge interactions. Pedestrian phase locking due to footstep phase adjustment is suspected to be the main cause of its large lateral vibrations; however, its role in the initiation of wobbling was debated. We develop foot force models of pedestrians’ response to bridge motion and detailed, yet analytically tractable, models of crowd phase locking. We use biomechanically inspired models of crowd lateral movement to investigate to what degree pedestrian synchrony must be present for a bridge to wobble significantly and what is a critical crowd size. Our results can be used as a safety guideline for designing pedestrian bridges or limiting the maximum occupancy of an existing bridge. The pedestrian models can be used as “crash test dummies” when numerically probing a specific bridge design. This is particularly important because the U.S. code for designing pedestrian bridges does not contain explicit guidelines that account for the collective pedestrian behavior. PMID:29296679

Foot force models of crowd dynamics on a wobbly bridge.

PubMed

Belykh, Igor; Jeter, Russell; Belykh, Vladimir

2017-11-01

Modern pedestrian and suspension bridges are designed using industry standard packages, yet disastrous resonant vibrations are observed, necessitating multimillion dollar repairs. Recent examples include pedestrian-induced vibrations during the opening of the Solférino Bridge in Paris in 1999 and the increased bouncing of the Squibb Park Bridge in Brooklyn in 2014. The most prominent example of an unstable lively bridge is the London Millennium Bridge, which started wobbling as a result of pedestrian-bridge interactions. Pedestrian phase locking due to footstep phase adjustment is suspected to be the main cause of its large lateral vibrations; however, its role in the initiation of wobbling was debated. We develop foot force models of pedestrians' response to bridge motion and detailed, yet analytically tractable, models of crowd phase locking. We use biomechanically inspired models of crowd lateral movement to investigate to what degree pedestrian synchrony must be present for a bridge to wobble significantly and what is a critical crowd size. Our results can be used as a safety guideline for designing pedestrian bridges or limiting the maximum occupancy of an existing bridge. The pedestrian models can be used as "crash test dummies" when numerically probing a specific bridge design. This is particularly important because the U.S. code for designing pedestrian bridges does not contain explicit guidelines that account for the collective pedestrian behavior.

Load Distribution Factors for Composite Multicell Box Girder Bridges

NASA Astrophysics Data System (ADS)

Tiwari, Sanjay; Bhargava, Pradeep

2017-12-01

Cellular steel section composite with a concrete deck is one of the most suitable superstructures in resisting torsional and warping effects induced by highway loading. This type of structure has inherently created new design problems for engineers in estimating its load distribution when subjected to moving vehicles. Indian Codes of Practice does not provide any specific guidelines for the design of straight composite concrete deck-steel multi-cell bridges. To meet the practical requirements arising during the design process, a simple design method is needed for straight composite multi-cell bridges in the form of load distribution factors for moment and shear. This work presents load distribution characteristics of straight composite multi-cell box girder bridges under IRC trains of loads.

Structural Impact of Construction Loads : [Technical Summary

DOT National Transportation Integrated Search

2012-01-01

Numerous bridge construction accidents have occurred : because of construction loadings, which are an underemphasized : topic in many specifications and design : manuals. Bridge girders are least stable during the : construction phase, so it is impor...

Structural Impact of Construction Loads

DOT National Transportation Integrated Search

2012-08-01

Numerous bridge construction accidents have occurred across the country because of construction loadings, which are an underemphasized : topic in many DOT specifications and design manuals. Bridge girders are least stable when they are subjected to c...

Structural Impact of Construction Loads

DOT National Transportation Integrated Search

2012-08-01

Numerous bridge construction accidents have occurred across the country because of construction loadings, which are an underemphasized topic in many DOT specifications and design manuals. Bridge girders are least stable when they are subjected to con...

Crashworthy railing for timber bridges

Treesearch

Michael A. Ritter; Ronald K. Faller; Sheila Rimal Duwadi

1999-01-01

Bridge railing systems in the United States have historically beers designed based on static load criteria given in the American Association of State Highway and Transportation 0fficials (AASHTO) Standard Specifications for Highway Bridges. In the past decade, full-scale vehicle crash testing has been recognized as a more appropriate and reliable method of evaluating...

Standard plans for southern pine bridges

Treesearch

P. D. Hilbrich Lee; M. A. Ritter; M. H. Triche

1995-01-01

The development of standardized timber bridge plans and specifications is a key element in improving design and construction practices. The bridge plans presented were developed as a cooperative effort between the USDA Forest Service, Forest Products Laboratory (FPL); the University of Alabama; and the Southern Pine Council and are the first step in developing...

A Bridge Program's Effect on Non-College Ready Student Veterans

ERIC Educational Resources Information Center

Morris, Brett Eugene

2013-01-01

This study examined whether a bridge program designed to remediate academic deficiencies for a cohort of student veterans has any bearing on their post-secondary success and persistence. Specifically, this study examined the Veterans Bridge to College Success (VBCS) pilot program at Eastern Kentucky University, which provides an admission pathway…

23 CFR 625.4 - Standards, policies, and standard specifications.

Code of Federal Regulations, 2014 CFR

2014-04-01

...) Pavement Design, refer to 23 CFR part 626. (b) Bridges and structures. (1) Standard Specifications for... TRAFFIC OPERATIONS DESIGN STANDARDS FOR HIGHWAYS § 625.4 Standards, policies, and standard specifications.... (a) Roadway and appurtenances. (1) A Policy on Geometric Design of Highways and Streets, AASHTO 2001...

23 CFR 625.4 - Standards, policies, and standard specifications.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) Pavement Design, refer to 23 CFR part 626. (b) Bridges and structures. (1) Standard Specifications for... TRAFFIC OPERATIONS DESIGN STANDARDS FOR HIGHWAYS § 625.4 Standards, policies, and standard specifications.... (a) Roadway and appurtenances. (1) A Policy on Geometric Design of Highways and Streets, AASHTO 2001...

23 CFR 625.4 - Standards, policies, and standard specifications.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) Pavement Design, refer to 23 CFR part 626. (b) Bridges and structures. (1) Standard Specifications for... TRAFFIC OPERATIONS DESIGN STANDARDS FOR HIGHWAYS § 625.4 Standards, policies, and standard specifications.... (a) Roadway and appurtenances. (1) A Policy on Geometric Design of Highways and Streets, AASHTO 2001...

23 CFR 625.4 - Standards, policies, and standard specifications.

Code of Federal Regulations, 2010 CFR

2010-04-01

...) Pavement Design, refer to 23 CFR part 626. (b) Bridges and structures. (1) Standard Specifications for... TRAFFIC OPERATIONS DESIGN STANDARDS FOR HIGHWAYS § 625.4 Standards, policies, and standard specifications.... (a) Roadway and appurtenances. (1) A Policy on Geometric Design of Highways and Streets, AASHTO 2001...

23 CFR 625.4 - Standards, policies, and standard specifications.

Code of Federal Regulations, 2011 CFR

2011-04-01

...) Pavement Design, refer to 23 CFR part 626. (b) Bridges and structures. (1) Standard Specifications for... TRAFFIC OPERATIONS DESIGN STANDARDS FOR HIGHWAYS § 625.4 Standards, policies, and standard specifications.... (a) Roadway and appurtenances. (1) A Policy on Geometric Design of Highways and Streets, AASHTO 2001...

Structural Impact of Construction Loads : [Technical Summary

DOT National Transportation Integrated Search

2012-01-01

Numerous bridge construction accidents have occurred because of construction loadings, which are an underemphasized topic in many specifications and design manuals. Bridge girders are least stable during the construction phase, so it is important for...

Engineering Design Processes in Seventh-Grade Classrooms: Bridging the Engineering Education Gap

ERIC Educational Resources Information Center

English, Lyn D.; Hudson, Peter B.; Dawes, Les

2012-01-01

This paper reports on some findings from the first year of a three-year longitudinal study, in which seventh- to ninth-graders were introduced to engineering education. Specifically, the paper addresses students' responses to an initial design activity involving bridge construction, which was implemented at the end of seventh grade. This paper…

Invited Article: Bridging the Gap--Supporting the Transition from High School to College

ERIC Educational Resources Information Center

Frischmann, Julie A.; Moor, Kelly S.

2017-01-01

Idaho State University's Bengal Bridge is a summer program designed to help students successfully transition from high school to their first year of college at Idaho State University. All Bridge students at ISU take two general education courses, plus an additional credit of supplemental instruction focused on academic strategies specific to the…

Improved Simplified Methods for Effective Seismic Analysis and Design of Isolated and Damped Bridges in Western and Eastern North America

NASA Astrophysics Data System (ADS)

Koval, Viacheslav

The seismic design provisions of the CSA-S6 Canadian Highway Bridge Design Code and the AASHTO LRFD Seismic Bridge Design Specifications have been developed primarily based on historical earthquake events that have occurred along the west coast of North America. For the design of seismic isolation systems, these codes include simplified analysis and design methods. The appropriateness and range of application of these methods are investigated through extensive parametric nonlinear time history analyses in this thesis. It was found that there is a need to adjust existing design guidelines to better capture the expected nonlinear response of isolated bridges. For isolated bridges located in eastern North America, new damping coefficients are proposed. The applicability limits of the code-based simplified methods have been redefined to ensure that the modified method will lead to conservative results and that a wider range of seismically isolated bridges can be covered by this method. The possibility of further improving current simplified code methods was also examined. By transforming the quantity of allocated energy into a displacement contribution, an idealized analytical solution is proposed as a new simplified design method. This method realistically reflects the effects of ground-motion and system design parameters, including the effects of a drifted oscillation center. The proposed method is therefore more appropriate than current existing simplified methods and can be applicable to isolation systems exhibiting a wider range of properties. A multi-level-hazard performance matrix has been adopted by different seismic provisions worldwide and will be incorporated into the new edition of the Canadian CSA-S6-14 Bridge Design code. However, the combined effect and optimal use of isolation and supplemental damping devices in bridges have not been fully exploited yet to achieve enhanced performance under different levels of seismic hazard. A novel Dual-Level Seismic Protection (DLSP) concept is proposed and developed in this thesis which permits to achieve optimum seismic performance with combined isolation and supplemental damping devices in bridges. This concept is shown to represent an attractive design approach for both the upgrade of existing seismically deficient bridges and the design of new isolated bridges.

Building Bridges between Knowledge and Practice: A University-School District Leadership Preparation Program Partnership

ERIC Educational Resources Information Center

Sanzo, Karen L.; Myran, Steve; Clayton, Jennifer K.

2011-01-01

Purpose: The purpose of this paper is to provide a Year 1 account of a partnership between a university and rural school district focusing specifically on how the project has helped to bridge the theory to practice divide and strengthen university-district ties. Design/methodology/approach: A design-based research paradigm was utilized to…

Improved LRFD/LRFR specifications for permit and fatigue load truck.

DOT National Transportation Integrated Search

2011-01-01

Bridge design and evaluation are moving toward the American Association of State Highway and Transportation : Officials (AASHTO) load and resistance factor design/load and resistance factor rating (LRFD/LRFR) : specifications using calibrated truck l...

Real-time seismic monitoring of the integrated cape girardeau bridge array and recorded earthquake response

USGS Publications Warehouse

Celebi, M.

2006-01-01

This paper introduces the state of the art, real-time and broad-band seismic monitoring network implemented for the 1206 m [3956 ft] long, cable-stayed Bill Emerson Memorial Bridge in Cape Girardeau (MO), a new Mississippi River crossing, approximately 80 km from the epicentral region of the 1811-1812 New Madrid earthquakes. The bridge was designed for a strong earthquake (magnitude 7.5 or greater) during the design life of the bridge. The monitoring network comprises a total of 84 channels of accelerometers deployed on the superstructure, pier foundations and at surface and downhole free-field arrays of the bridge. The paper also presents the high quality response data obtained from the network. Such data is aimed to be used by the owner, researchers and engineers to assess the performance of the bridge, to check design parameters, including the comparison of dynamic characteristics with actual response, and to better design future similar bridges. Preliminary analyses of ambient and low amplitude small earthquake data reveal specific response characteristics of the bridge and the free-field. There is evidence of coherent tower, cable, deck interaction that sometimes results in amplified ambient motions. Motions at the lowest tri-axial downhole accelerometers on both MO and IL sides are practically free from any feedback from the bridge. Motions at the mid-level and surface downhole accelerometers are influenced significantly by feedback due to amplified ambient motions of the bridge. Copyright ASCE 2006.

An industrialized construction approach to concrete superstructures for bridges.

DOT National Transportation Integrated Search

1974-01-01

The objective of this study was to develop drawings for a specific site or sites that incorporated the best concepts of industrialized bridge superstructure construction, that is, great emphasis was placed upon the use of modular design and assembly ...

Behavior and design of large structural concrete bridge pier overhangs.

DOT National Transportation Integrated Search

1997-02-01

In designing large cantilever bent caps for use on recent projects under current AASHTO design specifications, : designers were faced with considerable uncertainties. Questions arose when designers attempted to satisfy : both serviceability and stren...

Analysis of Static Load Test of a Masonry Arch Bridge

NASA Astrophysics Data System (ADS)

Shi, Jing-xian; Fang, Tian-tian; Luo, Sheng

2018-03-01

In order to know whether the carrying capacity of the masonry arch bridge built in the 1980s on the shipping channel entering and coming out of the factory of a cement company can meet the current requirements of Level II Load of highway, through the equivalent load distribution of the test vehicle according to the current design specifications, this paper conducted the load test, evaluated the bearing capacity of the in-service stone arch bridge, and made theoretical analysis combined with Midas Civil. The results showed that under the most unfavorable load conditions the measured strain and deflection of the test sections were less than the calculated values, the bridge was in the elastic stage under the design load; the structural strength and stiffness of the bridge had a certain degree of prosperity, and under the in the current conditions of Level II load of highway, the bridge structure was in a safe state.

Dynamic Load on Continuous Multi-Lane Bridge Deck from Moving Vehicles

NASA Astrophysics Data System (ADS)

ZHU, X. Q.; LAW, S. S.

2002-04-01

The dynamic loading on a multi-lane continuous bridge deck due to vehicles moving on top at a constant velocity is investigated. The bridge is modelled as a multi-span continuous orthotropic rectangular plate with line rigid intermediate supports. The vehicle is simulated as a two-axle three-dimensional vehicle model with seven degrees of freedom according to the H20-44 vehicle design loading (AASHTO LRFD Bridge Design Specifications 1998 American Association of State Highway and Transportation Officials [1]). The dynamic behavior of the bridge deck under single and several vehicles moving in different lanes is analyzed using the orthotropic plate theory and modal superposition technique. The dynamic loading is studied in terms of the dynamic impact factor of the bridge deck. The impact factor is found varying in an opposite trend as the dynamic responses for the different loading cases under study.

Synthesis of falsework, formwork and scaffolding for highway bridge structures

DOT National Transportation Integrated Search

1994-08-01

Following the collapse of the Route 198 bridge over the Baltimore-Washington Parkway in 1989, the FHWA determined that there was a need to reassess, on a national level, the specifications currently used to design, construct, and inspect falsework an...

Heat-curved girders : deflections and camber loss during and subsequent to bridge construction.

DOT National Transportation Integrated Search

1982-01-01

The present AASHTO bridge design specifications require that additional camber be built into steel girders that are to be heat curved. The additional camber is provided to allow for subsequent losses due to the dissipation of residual stresses impose...

Next generation seismic fragility curves for California bridges incorporating the evolution in seismic design philosophy

NASA Astrophysics Data System (ADS)

Ramanathan, Karthik Narayan

Quantitative and qualitative assessment of the seismic risk to highway bridges is crucial in pre-earthquake planning, and post-earthquake response of transportation systems. Such assessments provide valuable knowledge about a number of principal effects of earthquakes such as traffic disruption of the overall highway system, impact on the regions’ economy and post-earthquake response and recovery, and more recently serve as measures to quantify resilience. Unlike previous work, this study captures unique bridge design attributes specific to California bridge classes along with their evolution over three significant design eras, separated by the historic 1971 San Fernando and 1989 Loma Prieta earthquakes (these events affected changes in bridge seismic design philosophy). This research developed next-generation fragility curves for four multispan concrete bridge classes by synthesizing new knowledge and emerging modeling capabilities, and by closely coordinating new and ongoing national research initiatives with expertise from bridge designers. A multi-phase framework was developed for generating fragility curves, which provides decision makers with essential tools for emergency response, design, planning, policy support, and maximizing investments in bridge retrofit. This framework encompasses generational changes in bridge design and construction details. Parameterized high-fidelity three-dimensional nonlinear analytical models are developed for the portfolios of bridge classes within different design eras. These models incorporate a wide range of geometric and material uncertainties, and their responses are characterized under seismic loadings. Fragility curves were then developed considering the vulnerability of multiple components and thereby help to quantify the performance of highway bridge networks and to study the impact of seismic design principles on the performance within a bridge class. This not only leads to the development of fragility relations that are unique and better suited for bridges in California, but also leads to the creation of better bridge classes and sub-bins that have more consistent performance characteristics than those currently provided by the National Bridge Inventory. Another important feature of this research is associated with the development of damage state definitions and grouping of bridge components in a way that they have similar consequences in terms of repair and traffic implications following a seismic event. These definitions are in alignment with the California Department of Transportation’s design and operational experience, thereby enabling better performance assessment, emergency response, and management in the aftermath of a seismic event. The fragility curves developed as a part of this research will be employed in ShakeCast, a web-based post-earthquake situational awareness application that automatically retrieves earthquake shaking data and generates potential damage assessment notifications for emergency managers and responders.

The Principle of the Micro-Electronic Neural Bridge and a Prototype System Design.

PubMed

Huang, Zong-Hao; Wang, Zhi-Gong; Lu, Xiao-Ying; Li, Wen-Yuan; Zhou, Yu-Xuan; Shen, Xiao-Yan; Zhao, Xin-Tai

2016-01-01

The micro-electronic neural bridge (MENB) aims to rebuild lost motor function of paralyzed humans by routing movement-related signals from the brain, around the damage part in the spinal cord, to the external effectors. This study focused on the prototype system design of the MENB, including the principle of the MENB, the neural signal detecting circuit and the functional electrical stimulation (FES) circuit design, and the spike detecting and sorting algorithm. In this study, we developed a novel improved amplitude threshold spike detecting method based on variable forward difference threshold for both training and bridging phase. The discrete wavelet transform (DWT), a new level feature coefficient selection method based on Lilliefors test, and the k-means clustering method based on Mahalanobis distance were used for spike sorting. A real-time online spike detecting and sorting algorithm based on DWT and Euclidean distance was also implemented for the bridging phase. Tested by the data sets available at Caltech, in the training phase, the average sensitivity, specificity, and clustering accuracies are 99.43%, 97.83%, and 95.45%, respectively. Validated by the three-fold cross-validation method, the average sensitivity, specificity, and classification accuracy are 99.43%, 97.70%, and 96.46%, respectively.

Appendix B : small beam tests.

DOT National Transportation Integrated Search

2013-03-01

The AASHTO LRFD Bridge Design Specifications (2007) require that confinement : reinforcement be placed around prestressing strands in the bottom bulb of pretensioned concrete : beams. Although the AASHTO specifications contain prescriptive requiremen...

Reliability-based evaluation of bridge components for consistent safety margins.

DOT National Transportation Integrated Search

2010-10-01

The Load and Resistant Factor Design (LRFD) approach is based on the concept of structural reliability. The approach is more : rational than the former design approaches such as Load Factor Design or Allowable Stress Design. The LRFD Specification fo...

Experimental evaluation and design of unfilled and concrete-filled FRP composite piles : Task 4B : material & construction specifications : final report.

DOT National Transportation Integrated Search

2015-07-01

The overall goal of this project is the experimental evaluation and design of unfilled and concrete-filled FRP composite piles for load-bearing in bridges. This report covers Task 4B, Materials and Construction Specifications. : This technical report...

Optimum design of bridges with superelastic-friction base isolators against near-field earthquakes

NASA Astrophysics Data System (ADS)

Ozbulut, Osman E.; Hurlebaus, Stefan

2010-04-01

The seismic response of a multi-span continuous bridge isolated with novel superelastic-friction base isolator (S-FBI) is investigated under near-field earthquakes. The isolation system consists of a flat steel-Teflon sliding bearing and a superelastic NiTi shape memory alloy (SMA) device. Sliding bearings limit the maximum seismic forces transmitted to the superstructure to a certain value that is a function of friction coefficient of sliding interface. Superelastic SMA device provides restoring capability to the isolation system together with additional damping characteristics. The key design parameters of an S-FBI system are the natural period of the isolated, yielding displacement of SMA device, and the friction coefficient of the sliding bearings. The goal of this study is to obtain optimal values for each design parameter by performing sensitivity analyses of the isolated bridge. First, a three-span continuous bridge is modeled as a two-degrees-of-freedom with S-FBI system. A neuro-fuzzy model is used to capture rate-dependent nonlinear behavior of SMA device. A time-dependent method which employs wavelets to adjust accelerograms to match a target response spectrum with minimum changes on the other characteristics of ground motions is used to generate ground motions used in the simulations. Then, a set of nonlinear time history analyses of the isolated bridge is performed. The variation of the peak response quantities of the isolated bridge is shown as a function of design parameters. Also, the influence of temperature variations on the effectiveness of S-FBI system is evaluated. The results show that the optimum design of the isolated bridge with S-FBI system can be achieved by a judicious specification of design parameters.

Appendix G : end region design models.

DOT National Transportation Integrated Search

2013-03-01

The 2007 AASHTO LRFD Bridge Design Specifications contain prescriptive : requirements for the quantity and placement of confinement reinforcement located in the bottom : flange of pretensioned concrete I-girders. This chapter proposes a rational mode...

Elimination of deck joints using a corrosion resistant FRP approach

NASA Astrophysics Data System (ADS)

Aleti, Ashok Reddy

The research presented herein describes the development of durable link slabs for jointless bridge decks based on using FRP grid for reinforcement. Specifically, the ductility of the FRP material was utilized to accommodate bridge deck deformations imposed by girder deflection, temperature variations, and concrete shrinkage. It would also provide a solution to a number of deterioration problems associated with bridge deck joints. The design concept of the link slabs was then examined to form the basis of design for FRP grid link slabs. Improved design of FRP grid link slab/concrete deck slab interface was confirmed in the numerical analysis. The mechanical properties between the FRP grid and concrete were evaluated. The behavior of the link slab was investigated and confirmed for durability. The results indicated that the technique would allow simultaneous achievement of structural need (lower flexural stiffness of the link slab approaching the behavior of a hinge) and durability need of the link slab. Also, the development length results confirm that the bond between the FRP grid and the concrete was highly improved. The overall investigation supports the contention that durable jointless concrete bridge decks may be designed and constructed with FRP grid link slabs. It is recommended that the link slab technique be used during new construction of the bridge decks and in repair and retrofit of the bridge decks.

A Bridge to Active Learning: A Summer Bridge Program Helps Students Maximize Their Active-Learning Experiences and the Active-Learning Experiences of Others

PubMed Central

Cooper, Katelyn M.; Ashley, Michael; Brownell, Sara E.

2017-01-01

National calls to improve student academic success in college have sparked the development of bridge programs designed to help students transition from high school to college. We designed a 2-week Summer Bridge program that taught introductory biology content in an active-learning way. Through a set of exploratory interviews, we unexpectedly identified that Bridge students had developed sophisticated views of active learning, even though this was not an explicit goal of the program. We conducted an additional set of semistructured interviews that focused on active learning and compared the interviews of Bridge students with those from non-Bridge students who had been eligible for but did not participate in the program. We used the constant comparative method to identify themes from the interviews. We found that Bridge students perceived that, because they knew how to approach active learning and viewed it as important, they benefited more from active learning in introductory biology than non-Bridge students. Specifically, Bridge students seemed to be more aware of their own learning gains from participating in active learning. Compared with the majority of non-Bridge students, the majority of Bridge students described using a greater variety of strategies to maximize their experiences in active learning. Finally, in contrast to non-Bridge students, Bridge students indicated that they take an equitable approach to group work. These findings suggest that we may be able to prime students to maximize their own and other’s experiences in active learning. PMID:28232588

Wireless sensing system for bridge condition assessment and health monitoring

NASA Astrophysics Data System (ADS)

Gangone, Michael V.; Whelan, Matthew J.; Janoyan, Kerop D.

2009-03-01

Discussed in this paper is the deployment of a universal and low-cost dense wireless sensor system for structural monitoring, load rating and condition assessment of bridges. The wireless sensor system developed is designed specifically for diagnostic bridge monitoring, providing independent conditioning for both accelerometers and strain transducers in addition to high-rate wireless data transmission. The system was field deployed on a three span simply supported bridge superstructure, where strain and acceleration measurements were obtained simultaneously and in realtime at critical locations under several loading conditions, providing reliable quantitative information as to the actual performance level of the bridge. Monitoring was also conducted as the bridge was subjected to various controlled damage scenarios on the final day of testing. Select cases of detected damage using strain and modal based analysis are presented.

The Semantic Environment: Heuristics for a Cross-Context Human-Information Interaction Model

NASA Astrophysics Data System (ADS)

Resmini, Andrea; Rosati, Luca

This chapter introduces a multidisciplinary holistic approach for the general design of successful bridge experiences as a cross-context human-information interaction model. Nowadays it is common to interact through a number of different domains in order to communicate successfully, complete a task, or elicit a desired response: Users visit a reseller’s web site to find a specific item, book it, then drive to the closest store to complete their purchase. As such, one of the crucial challenges user experience design will face in the near future is how to structure and provide bridge experiences seamlessly spanning multiple communication channels or media formats for a specific purpose.

Bridge scour countermeasure assessments at select bridges in the United States, 2014–16

USGS Publications Warehouse

Dudunake, Taylor J.; Huizinga, Richard J.; Fosness, Ryan L.

2017-05-23

In 2009, the Federal Highway Administration published Hydraulic Engineering Circular No. 23 (HEC-23) to provide specific design and implementation guidelines for bridge scour and stream instability countermeasures. However, the effectiveness of countermeasures implemented over the past decade following those guidelines has not been evaluated. Therefore, in 2013, the U.S. Geological Survey, in cooperation with the Federal Highway Administration, began a study to assess the current condition of bridge-scour countermeasures at selected sites to evaluate their effectiveness. Bridge-scour countermeasures were assessed during 2014-2016. Site assessments included reviewing countermeasure design plans, summarizing the peak and daily streamflow history, and assessments at each site. Each site survey included a photo log summary, field form, and topographic and bathymetric geospatial data and metadata. This report documents the study area and site-selection criteria, explains the survey methods used to evaluate the condition of countermeasures, and presents the complete documentation for each countermeasure assessment.

Benchmark model correction of monitoring system based on Dynamic Load Test of Bridge

NASA Astrophysics Data System (ADS)

Shi, Jing-xian; Fan, Jiang

2018-03-01

Structural health monitoring (SHM) is a field of research in the area, and it’s designed to achieve bridge safety and reliability assessment, which needs to be carried out on the basis of the accurate simulation of the finite element model. Bridge finite element model is simplified of the structural section form, support conditions, material properties and boundary condition, which is based on the design and construction drawings, and it gets the calculation models and the results.But according to the design and specification requirements established finite element model due to its cannot fully reflect the true state of the bridge, so need to modify the finite element model to obtain the more accurate finite element model. Based on Da-guan river crossing of Ma - Zhao highway in Yunnan province as the background to do the dynamic load test test, we find that the impact coefficient of the theoretical model of the bridge is very different from the coefficient of the actual test, and the change is different; according to the actual situation, the calculation model is adjusted to get the correct frequency of the bridge, the revised impact coefficient found that the modified finite element model is closer to the real state, and provides the basis for the correction of the finite model.

UDOT calibration of AASHTO's new prestress loss design equations.

DOT National Transportation Integrated Search

2009-07-01

In the next edition of the AASHTO LRFD Bridge Design Specifications the procedure to calculate prestress losses will change dramatically. The new equations are empirically based on high performance concrete from four states (Nebraska, New Hampshire, ...

UDOT's calibration of AASHTO's new prestress loss design equations.

DOT National Transportation Integrated Search

2009-07-01

In the next edition of the AASHTO LRFD Bridge Design Specifications the procedure to calculate prestress losses will change dramatically. The new equations are empirically based on high performance concrete from four states (Nebraska, New Hampshire, ...

Partially entangled states bridge in quantum teleportation

NASA Astrophysics Data System (ADS)

Cai, Xiao-Fei; Yu, Xu-Tao; Shi, Li-Hui; Zhang, Zai-Chen

2014-10-01

The traditional method for information transfer in a quantum communication system using partially entangled state resource is quantum distillation or direct teleportation. In order to reduce the waiting time cost in hop-by-hop transmission and execute independently in each node, we propose a quantum bridging method with partially entangled states to teleport quantum states from source node to destination node. We also prove that the designed specific quantum bridging circuit is feasible for partially entangled states teleportation across multiple intermediate nodes. Compared to two traditional ways, our partially entanglement quantum bridging method uses simpler logic gates, has better security, and can be used in less quantum resource situation.

Salt-bridge networks within globular and disordered proteins: characterizing trends for designable interactions.

PubMed

Basu, Sankar; Mukharjee, Debasish

2017-07-01

There has been considerable debate about the contribution of salt bridges to the stabilization of protein folds, in spite of their participation in crucial protein functions. Salt bridges appear to contribute to the activity-stability trade-off within proteins by bringing high-entropy charged amino acids into close contacts during the course of their functions. The current study analyzes the modes of association of salt bridges (in terms of networks) within globular proteins and at protein-protein interfaces. While the most common and trivial type of salt bridge is the isolated salt bridge, bifurcated salt bridge appears to be a distinct salt-bridge motif having a special topology and geometry. Bifurcated salt bridges are found ubiquitously in proteins and interprotein complexes. Interesting and attractive examples presenting different modes of interaction are highlighted. Bifurcated salt bridges appear to function as molecular clips that are used to stitch together large surface contours at interacting protein interfaces. The present work also emphasizes the key role of salt-bridge-mediated interactions in the partial folding of proteins containing long stretches of disordered regions. Salt-bridge-mediated interactions seem to be pivotal to the promotion of "disorder-to-order" transitions in small disordered protein fragments and their stabilization upon binding. The results obtained in this work should help to guide efforts to elucidate the modus operandi of these partially disordered proteins, and to conceptualize how these proteins manage to maintain the required amount of disorder even in their bound forms. This work could also potentially facilitate explorations of geometrically specific designable salt bridges through the characterization of composite salt-bridge networks. Graphical abstract ᅟ.

Rating precast prestressed concrete bridges for shear

DOT National Transportation Integrated Search

2008-12-01

Shear capacity of real-world prestressed concrete girders designed in the 1960s and 1970s is a concern because : AASHTO Standard Specifications (AASHTO-STD) employed the quarter-point rule for shear design, which is less : conservative for shea...

Calibration of load and resistance factors in LRFD foundation design specifications

DOT National Transportation Integrated Search

2011-02-01

This report summarizes the findings and recommendations on the impact of foundation settlements on the reliability of bridge superstructures. As a collaborative effort of an overall initiative for the development of LRFD foundation design specificati...

Embedded data collector (EDC) phase II load and resistance factor design (LRFD) : [summary].

DOT National Transportation Integrated Search

2015-07-01

Piles that support bridge structures are designed for the specific site characteristics and loads : that the piles are expected to bear. In Florida, driven piles are monitored during installation : (dynamically tested) to assess resistance, com...

Project 2d: Calibration of Load and Resistance Factors in LRFD Foundation Design Specifications

DOT National Transportation Integrated Search

2011-02-01

This report summarizes the findings and recommendations on the impact of foundation settlements on the reliability of bridge superstructures. As a : collaborative effort of an overall initiative for the development of LRFD foundation design specifica...

Design of mechanically stabilized earth wall connections and end of walls subjected to seismic loads.

DOT National Transportation Integrated Search

2014-01-01

The 4th Edition of the AASHTO LRFD Bridge Design Specifications requires all states to design for a 1,000- : year return period earthquake, as opposed to earlier editions 500-year return period. In response to this : requirement, the Colorado Depa...

CF60 Concrete Composition Design and Application on Fudiankou Xijiang Super Large Bridge

NASA Astrophysics Data System (ADS)

Qiu, Yi Mei; Wen, Sen Yuan; Chen, Jun Xiang

2018-06-01

Guangxi Wuzhou City Ring Road Fudiankou Xijiang super large bridge CF60 concrete is a new multi-phase composite high-performance concrete, this paper for the Fudiankou Xijiang bridge structure and characteristics of the project, in accordance with the principle of local materials and technical specification requirements, combined with the site conditions of CF60 engineering high performance concrete component materials, proportion and the technical performance, quantify the main physical and mechanical performance index. Analysis main influencing factors of the technical indicators, reasonable adjustment of concrete mix design parameters, and the use of technical means of admixture and multi-function composite admixture of concrete, obtain the optimal proportion of good work, process, mechanical properties stability and durability of engineering properties, recommend and verification of concrete mix; to explore the CF60 high performance concrete Soil in the Fudiankou Xijiang bridge application technology, detection and tracking the quality of concrete construction, concrete structure during the construction of the key technology and control points is proposed, evaluation of CF60 high performance concrete in the actual engineering application effect and benefit to ensure engineering quality of bridge structure and service life, and super long span bridge engineering construction to provide basis and reference.

Efficient field testing for load rating railroad bridges

NASA Astrophysics Data System (ADS)

Schulz, Jeffrey L.; Brett C., Commander

1995-06-01

As the condition of our infrastructure continues to deteriorate, and the loads carried by our bridges continue to increase, an ever growing number of railroad and highway bridges require load limits. With safety and transportation costs at both ends of the spectrum. the need for accurate load rating is paramount. This paper describes a method that has been developed for efficient load testing and evaluation of short- and medium-span bridges. Through the use of a specially-designed structural testing system and efficient load test procedures, a typical bridge can be instrumented and tested at 64 points in less than one working day and with minimum impact on rail traffic. Various techniques are available to evaluate structural properties and obtain a realistic model. With field data, a simple finite element model is 'calibrated' and its accuracy is verified. Appropriate design and rating loads are applied to the resulting model and stress predictions are made. This technique has been performed on numerous structures to address specific problems and to provide accurate load ratings. The merits and limitations of this approach are discussed in the context of actual examples of both rail and highway bridges that were tested and evaluated.

The Deformation of Overburden Soil and Interaction with Pile Foundations of Bridges Induced by Normal Faulting

NASA Astrophysics Data System (ADS)

Wu, Liang-Chun; Li, Chien-Hung; Chan, Pei-Chen; Lin, Ming-Lang

2017-04-01

According to the investigations of well-known disastrous earthquakes in recent years, ground deformation induced by faulting is one of the causes for engineering structure damages in addition to strong ground motion. Most of structures located on faulting zone has been destroyed by fault offset. Take the Norcia Earthquake in Italy (2016, Mw=6.2) as an example, the highway bridge in Arquata crossing the rupture area of the active normal fault suffered a quantity of displacement which causing abutment settlement, the piers of bridge fractured and so on. However, The Seismic Design Provisions and Commentary for Highway Bridges in Taiwan, the stating of it in the general rule of first chapter, the design in bridges crossing active fault: "This specification is not applicable of making design in bridges crossing or near active fault, that design ought to the other particular considerations ".This indicates that the safty of bridges crossing active fault are not only consider the seismic performance, the most ground deformation should be attended. In this research, to understand the failure mechanism and the deformation characteristics, we will organize the case which the bridges subjected faulting at home and abroad. The processes of research are through physical sandbox experiment and numerical simulation by discrete element models (PFC3-D). The normal fault case in Taiwan is Shanchiao Fault. As above, the research can explore the deformation in overburden soil and the influences in the foundations of bridges by normal faulting. While we can understand the behavior of foundations, we will make the bridge superstructures into two separations, simple beam and continuous beam and make a further research on the main control variables in bridges by faulting. Through the above mentioned, we can then give appropriate suggestions about planning considerations and design approaches. This research presents results from sandbox experiment and 3-D numerical analysis to simulate overburden soil and embedded pile foundations subjected to normal faulting. In order to validate this numerical model, it is compared to sandbox experiments. Since the 3-D numerical analysis corresponds to the sandbox expeiments, the response of pile foundations and ground deformation induced by normal faulting are discussed. To understand the 3-D behavior of ground deformation and pile foundations, the observation such as the triangular shear zone, the width of primary deformation zone and the inclination, displacements, of the pile foundations are discussed in experiments and simulations. Furthermore, to understand the safty of bridges crossing faulting zone. The different superstructures of bridges, simple beam and continuous beam will be discussed subsequently in simulations.

Design, synthesis, insecticidal activity, and structure-activity relationship (SAR): studies of novel triazone derivatives containing a urea bridge group based on transient receptor potential (TRP) channels.

PubMed

Yang, Yan; Liu, Yuxiu; Song, Hongjian; Li, Yongqiang; Wang, Qingmin

2016-11-01

Numerous compounds containing urea bridge and biurea moieties are used in a variety of fields, especially as drugs and pesticides. To search for novel, environmentally benign and ecologically safe pesticides with unique modes of action, four series of novel triazone analogues containing urea, thiourea, biurea, and thiobiurea bridge, respectively, were designed and synthesized, according to various calcium ion channel inhibitors which act on transient receptor potential protein. Their structures were characterized by [Formula: see text] NMR, [Formula: see text] NMR, and HRMS. The insecticidal activities of the new compounds were obtained. The bioassay results indicated that compounds containing a thiourea bridge and a thiobiurea bridge exhibited excellent insecticidal activities against bean aphid. Specifically, compounds [Formula: see text], [Formula: see text], and [Formula: see text] exhibited 85, 90, and 95 % activities, respectively, at 10 mg/kg. Compounds [Formula: see text] (30 %), [Formula: see text] (35 %), [Formula: see text] (30 %), and [Formula: see text] (40 %) exhibited the approximate aphicidal activity of pymetrozine (30 %) at 5 mg/kg. In addition, some target compounds exhibited insecticidal activities against lepidopteran pests. From a molecular design standpoint, the information obtained in this study could help in the further design of new derivatives with improved insecticidal activities.

Salt-Bridge Energetics in Halophilic Proteins

PubMed Central

Nayek, Arnab; Sen Gupta, Parth Sarthi; Banerjee, Shyamashree; Mondal, Buddhadev; Bandyopadhyay, Amal K.

2014-01-01

Halophilic proteins have greater abundance of acidic over basic and very low bulky hydrophobic residues. Classical electrostatic stabilization was suggested as the key determinant for halophilic adaptation of protein. However, contribution of specific electrostatic interactions (i.e. salt-bridges) to overall stability of halophilic proteins is yet to be understood. To understand this, we use Adaptive-Poison-Boltzmann-Solver Methods along with our home-built automation to workout net as well as associated component energy terms such as desolvation energy, bridge energy and background energy for 275 salt-bridges from 20 extremely halophilic proteins. We then perform extensive statistical analysis on general and energetic attributes on these salt-bridges. On average, 8 salt-bridges per 150 residues protein were observed which is almost twice than earlier report. Overall contributions of salt-bridges are −3.0 kcal mol−1. Majority (78%) of salt-bridges in our dataset are stable and conserved in nature. Although, average contributions of component energy terms are equal, their individual details vary greatly from one another indicating their sensitivity to local micro-environment. Notably, 35% of salt-bridges in our database are buried and stable. Greater desolvation penalty of these buried salt-bridges are counteracted by stable network salt-bridges apart from favorable equal contributions of bridge and background terms. Recruitment of extensive network salt-bridges (46%) with a net contribution of −5.0 kcal mol−1 per salt-bridge, seems to be a halophilic design wherein favorable average contribution of background term (−10 kcal mol−1) exceeds than that of bridge term (−7 kcal mol−1). Interiors of proteins from halophiles are seen to possess relatively higher abundance of charge and polar side chains than that of mesophiles which seems to be satisfied by cooperative network salt-bridges. Overall, our theoretical analyses provide insight into halophilic signature in its specific electrostatic interactions which we hope would help in protein engineering and bioinformatics studies. PMID:24743799

Salt-bridge energetics in halophilic proteins.

PubMed

Nayek, Arnab; Sen Gupta, Parth Sarthi; Banerjee, Shyamashree; Mondal, Buddhadev; Bandyopadhyay, Amal K

2014-01-01

Halophilic proteins have greater abundance of acidic over basic and very low bulky hydrophobic residues. Classical electrostatic stabilization was suggested as the key determinant for halophilic adaptation of protein. However, contribution of specific electrostatic interactions (i.e. salt-bridges) to overall stability of halophilic proteins is yet to be understood. To understand this, we use Adaptive-Poison-Boltzmann-Solver Methods along with our home-built automation to workout net as well as associated component energy terms such as desolvation energy, bridge energy and background energy for 275 salt-bridges from 20 extremely halophilic proteins. We then perform extensive statistical analysis on general and energetic attributes on these salt-bridges. On average, 8 salt-bridges per 150 residues protein were observed which is almost twice than earlier report. Overall contributions of salt-bridges are -3.0 kcal mol-1. Majority (78%) of salt-bridges in our dataset are stable and conserved in nature. Although, average contributions of component energy terms are equal, their individual details vary greatly from one another indicating their sensitivity to local micro-environment. Notably, 35% of salt-bridges in our database are buried and stable. Greater desolvation penalty of these buried salt-bridges are counteracted by stable network salt-bridges apart from favorable equal contributions of bridge and background terms. Recruitment of extensive network salt-bridges (46%) with a net contribution of -5.0 kcal mol-1 per salt-bridge, seems to be a halophilic design wherein favorable average contribution of background term (-10 kcal mol-1) exceeds than that of bridge term (-7 kcal mol-1). Interiors of proteins from halophiles are seen to possess relatively higher abundance of charge and polar side chains than that of mesophiles which seems to be satisfied by cooperative network salt-bridges. Overall, our theoretical analyses provide insight into halophilic signature in its specific electrostatic interactions which we hope would help in protein engineering and bioinformatics studies.

Analysis, prediction, and case studies of early-age cracking in bridge decks

NASA Astrophysics Data System (ADS)

ElSafty, Adel; Graeff, Matthew K.; El-Gharib, Georges; Abdel-Mohti, Ahmed; Mike Jackson, N.

2016-06-01

Early-age cracking can adversely affect strength, serviceability, and durability of concrete bridge decks. Early age is defined as the period after final setting, during which concrete properties change rapidly. Many factors can cause early-age bridge deck cracking including temperature change, hydration, plastic shrinkage, autogenous shrinkage, and drying shrinkage. The cracking may also increase the effect of freeze and thaw cycles and may lead to corrosion of reinforcement. This research paper presents an analysis of causes and factors affecting early-age cracking. It also provides a tool developed to predict the likelihood and initiation of early-age cracking of concrete bridge decks. Understanding the concrete properties is essential so that the developed tool can accurately model the mechanisms contributing to the cracking of concrete bridge decks. The user interface of the implemented computer Excel program enables the user to input the properties of the concrete being monitored. The research study and the developed spreadsheet were used to comprehensively investigate the issue of concrete deck cracking. The spreadsheet is designed to be a user-friendly calculation tool for concrete mixture proportioning, temperature prediction, thermal analysis, and tensile cracking prediction. The study also provides review and makes recommendations on the deck cracking based mainly on the Florida Department of Transportation specifications and Structures Design Guidelines, and Bridge Design Manuals of other states. The results were also compared with that of other commercially available software programs that predict early-age cracking in concrete slabs, concrete pavement, and reinforced concrete bridge decks. The outcome of this study can identify a set of recommendations to limit the deck cracking problem and maintain a longer service life of bridges.

Bridge Failure Due to Inadequate Design of Bed Protection

NASA Astrophysics Data System (ADS)

Gupta, Yogita; Kaur, Suneet; Dindorkar, Nitin

2017-12-01

The shallow foundation is generally provided on non-erodible strata or where scour depth is less. It is also preferable for low perennial flow or standing water condition. In the present case study shallow foundation is adopted for box type bridge. The total length of the bridge is 132.98 m, consisting of eight unit of RCC box. Each unit is composed of three cell box. The bottom slab of box unit is acted as raft foundation, founded 500 mm below ground level. River bed protection work is provided on both upstream and downstream side along the whole length of the bridge as it is founded above scour level. The bridge collapsed during the monsoon just after two years of service. The present paper explains the cause of failure. This study on failure of the bridge illustrates the importance of bridge inspection before and after monsoon period and importance of the timely maintenance. Standard specifications of Indian Road Congress for the river bed protection work are also included.

36 CFR 1192.83 - Mobility aid accessibility.

Code of Federal Regulations, 2011 CFR

2011-07-01

... or boarding device (e.g., lift, ramp or bridge plate) complying with either paragraph (b) or (c) of... used by standees and designation of specific spaces is not required. (2) Exception. If lifts, ramps or... a single vehicle. (b) Vehicle lift—(1) Design load. The design load of the lift shall be at least...

36 CFR 1192.83 - Mobility aid accessibility.

Code of Federal Regulations, 2010 CFR

2010-07-01

... or boarding device (e.g., lift, ramp or bridge plate) complying with either paragraph (b) or (c) of... used by standees and designation of specific spaces is not required. (2) Exception. If lifts, ramps or... a single vehicle. (b) Vehicle lift—(1) Design load. The design load of the lift shall be at least...

A data management infrastructure for bridge monitoring

NASA Astrophysics Data System (ADS)

Jeong, Seongwoon; Byun, Jaewook; Kim, Daeyoung; Sohn, Hoon; Bae, In Hwan; Law, Kincho H.

2015-04-01

This paper discusses a data management infrastructure framework for bridge monitoring applications. As sensor technologies mature and become economically affordable, their deployment for bridge monitoring will continue to grow. Data management becomes a critical issue not only for storing the sensor data but also for integrating with the bridge model to support other functions, such as management, maintenance and inspection. The focus of this study is on the effective data management of bridge information and sensor data, which is crucial to structural health monitoring and life cycle management of bridge structures. We review the state-of-the-art of bridge information modeling and sensor data management, and propose a data management framework for bridge monitoring based on NoSQL database technologies that have been shown useful in handling high volume, time-series data and to flexibly deal with unstructured data schema. Specifically, Apache Cassandra and Mongo DB are deployed for the prototype implementation of the framework. This paper describes the database design for an XML-based Bridge Information Modeling (BrIM) schema, and the representation of sensor data using Sensor Model Language (SensorML). The proposed prototype data management framework is validated using data collected from the Yeongjong Bridge in Incheon, Korea.

23 CFR 650.207 - Plans, specifications and estimates.

Code of Federal Regulations, 2010 CFR

2010-04-01

... OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Erosion and Sediment Control on Highway Construction Projects... highway project designs for the control of erosion and sedimentation and the protection of water quality...

23 CFR 650.207 - Plans, specifications and estimates.

Code of Federal Regulations, 2014 CFR

2014-04-01

... OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Erosion and Sediment Control on Highway Construction Projects... highway project designs for the control of erosion and sedimentation and the protection of water quality...

23 CFR 650.207 - Plans, specifications and estimates.

Code of Federal Regulations, 2013 CFR

2013-04-01

... OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Erosion and Sediment Control on Highway Construction Projects... highway project designs for the control of erosion and sedimentation and the protection of water quality...

23 CFR 650.207 - Plans, specifications and estimates.

Code of Federal Regulations, 2011 CFR

2011-04-01

... OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Erosion and Sediment Control on Highway Construction Projects... highway project designs for the control of erosion and sedimentation and the protection of water quality...

23 CFR 650.207 - Plans, specifications and estimates.

Code of Federal Regulations, 2012 CFR

2012-04-01

... OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Erosion and Sediment Control on Highway Construction Projects... highway project designs for the control of erosion and sedimentation and the protection of water quality...

A Bridge to Active Learning: A Summer Bridge Program Helps Students Maximize Their Active-Learning Experiences and the Active-Learning Experiences of Others.

PubMed

Cooper, Katelyn M; Ashley, Michael; Brownell, Sara E

2017-01-01

National calls to improve student academic success in college have sparked the development of bridge programs designed to help students transition from high school to college. We designed a 2-week Summer Bridge program that taught introductory biology content in an active-learning way. Through a set of exploratory interviews, we unexpectedly identified that Bridge students had developed sophisticated views of active learning, even though this was not an explicit goal of the program. We conducted an additional set of semistructured interviews that focused on active learning and compared the interviews of Bridge students with those from non-Bridge students who had been eligible for but did not participate in the program. We used the constant comparative method to identify themes from the interviews. We found that Bridge students perceived that, because they knew how to approach active learning and viewed it as important, they benefited more from active learning in introductory biology than non-Bridge students. Specifically, Bridge students seemed to be more aware of their own learning gains from participating in active learning. Compared with the majority of non-Bridge students, the majority of Bridge students described using a greater variety of strategies to maximize their experiences in active learning. Finally, in contrast to non-Bridge students, Bridge students indicated that they take an equitable approach to group work. These findings suggest that we may be able to prime students to maximize their own and other's experiences in active learning. © 2017 K. M. Cooper et al. CBE—Life Sciences Education © 2017 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Formal Functional Test Designs: Bridging the Gap Between Test Requirements and Test Specifications

NASA Technical Reports Server (NTRS)

Hops, Jonathan

1993-01-01

This presentation describes the testing life cycle, the purpose of the test design phase, and test design methods and gives an example application. Also included is a description of Test Representation Language (TRL), a summary of the language, and an example of an application of TRL. A sample test requirement and sample test design are included.

Guardrails for use on historic bridges: volume 2--bridge deck overhang design.

DOT National Transportation Integrated Search

2016-11-01

Bridges that are designated historic present a special challenge to bridge engineers whenever rehabilitation work or improvements are : made to the bridges. Federal and state laws protect historically significant bridges, and railings on these bridge...

Arch-bridge Lift Process Monitoring by Using Packaged Optical Fibre Strain Sensors with Temperature Compensation

NASA Astrophysics Data System (ADS)

Mokhtar, M. R.; Sun, T.; Grattan, K. T. V.; Owens, K.; Kwasny, J.; Taylor, S. E.; Basheer, P. A. M.; Cleland, D.; Bai, Y.; Sonebi, M.; Davis, G.; Gupta, A.; Hogg, I.; Bell, B.; Doherty, W.; McKeague, S.; Moore, D.; Greeves, K.

2011-08-01

This paper presents a novel sensor design and packaging, specifically developed to allow fibre grating-based sensors to be used in harsh, in-the-field measurement conditions for accurate strain measurement, with full temperature compensation. After these sensors are carefully packaged and calibrated in the laboratory, they are installed onto the paragrid of a set of flat-packed concrete units, created specifically for forming a small-scale, lightweight and inexpensive flexi-arch bridge. During the arch-bridge lifting process, the sensors are used for real-time strain measurements to ensure the quality of the construction. During the work done, the sensors have demonstrated enhanced resilience when embedded in concrete structures, providing accurate and consistent strain measurements during the whole installation process and beyond into monitoring the integrity and use of the structure.

Bridging Water Resources Policy and Environmental Engineering in the Classroom at Cornell University

NASA Astrophysics Data System (ADS)

Walter, M. T.; Shaw, S. B.; Seifert, S.; Schwarz, T.

2006-12-01

Current university undergraduate students in environmental sciences and engineering are the next generation of environmental protection practitioners. Recognizing this, Cornell's Biological and Environmental Engineering department has developed a popular class, Watershed Engineering (BEE 473), specifically designed to bridge the too-common gap between water resources policy and state-of-art science and technology. Weekly homework assignments are to design real-life solutions to actual water resources problems, often with the objective of applying storm water policies to local situations. Where appropriate, usually in conjunction with recent amendments to the Federal Clean Water Act, this course introduces water resource protection tools and concepts developed in the Cornell Soil and Water Lab. Here we present several examples of how we build bridges between university classrooms and the complex world of water resources policy.

Design aids of NU I-girders bridges.

DOT National Transportation Integrated Search

2010-05-01

Precast prestressed concrete I-Girder bridges have become the most dominant bridge system in the United States. In the early design : stages, preliminary design becomes a vital first step in designing an economical bridge. Within the state of Nebrask...

A cloud-based information repository for bridge monitoring applications

NASA Astrophysics Data System (ADS)

Jeong, Seongwoon; Zhang, Yilan; Hou, Rui; Lynch, Jerome P.; Sohn, Hoon; Law, Kincho H.

2016-04-01

This paper describes an information repository to support bridge monitoring applications on a cloud computing platform. Bridge monitoring, with instrumentation of sensors in particular, collects significant amount of data. In addition to sensor data, a wide variety of information such as bridge geometry, analysis model and sensor description need to be stored. Data management plays an important role to facilitate data utilization and data sharing. While bridge information modeling (BrIM) technologies and standards have been proposed and they provide a means to enable integration and facilitate interoperability, current BrIM standards support mostly the information about bridge geometry. In this study, we extend the BrIM schema to include analysis models and sensor information. Specifically, using the OpenBrIM standards as the base, we draw on CSI Bridge, a commercial software widely used for bridge analysis and design, and SensorML, a standard schema for sensor definition, to define the data entities necessary for bridge monitoring applications. NoSQL database systems are employed for data repository. Cloud service infrastructure is deployed to enhance scalability, flexibility and accessibility of the data management system. The data model and systems are tested using the bridge model and the sensor data collected at the Telegraph Road Bridge, Monroe, Michigan.

DESIGNS FOR THE FUTURE: BRIDGING THE GAP BETWEEN ASSESSMENT OF CONDITION AND DIAGNOSIS OF IMPAIRMENT

EPA Science Inventory

As the EPA, states, and tribes move towards a consolidated assessment and listing process to satisfy requirements of the Clean Water Act, multi-purpose monitoring designs will be needed to assess regional condition as well as predict site-specific probabilities of impairment. Th...

The effect of bridge deck design methodology on crack control.

DOT National Transportation Integrated Search

2010-01-30

At present, the Idaho Transportation Department (ITD) Bridge Design Manual allows engineers to use the AASHTO empirical method to : design concrete bridge decks. However, the ITD Bridge Section would like to compare their design practices to those em...

49 CFR 237.131 - Design.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Design. 237.131 Section 237.131 Transportation... TRANSPORTATION BRIDGE SAFETY STANDARDS Repair and Modification of Bridges § 237.131 Design. Each repair or... component of a bridge shall be designed by a railroad bridge engineer. The design shall specify the manner...

Implementation of civionics in a second generation steel-free bridge deck

NASA Astrophysics Data System (ADS)

Klowak, Chad; Rivera, Evangeline; Mufti, Aftab

2005-05-01

As the design and construction of civil structures continue to evolve, it is becoming imperative that these structures be monitored for their health. In order to meet this need, the discipline of Civionics has emerged. Civionics is a new term coined from Civil-Electronics, which is derived from the application of electronics to civil structures. It is similar to the term Avionics, which is used in the aerospace industry. If structural health monitoring is to become part of civil structural engineering, it should include Civionics. It involves the application of electronics to civil structures and aims to assist engineers in realizing the full benefits of structural health monitoring (SHM). In past SHM field applications, the main reason for the failure of a sensor was not the installation of the sensor itself but the egress of the sensor cables. Often, the cables were not handled and protected correctly. For SHM to be successful, specifications must be written on the entire process, beginning with system design and concluding with data collection, interpretation, and management. Civionics specifications include the technical requirements for a SHM system which encompasses fibre optic sensors, cables, conduits, junction boxes and the control room. A specification for data collection and storage is currently being developed as well. In the spring of 2004 research engineers at the University of Manitoba constructed a full-scale second generation steel free bridge deck. The bridge deck is the first of its kind to fully incorporate a complete civionics structural health monitoring system to monitor the deck's behaviour during destructive testing. Throughout the construction of the bridge deck, the entire installation of the civionics system was carried out by research engineers simulating an actual implementation of such a system in a large scale construction environment. One major concern that consulting engineers have raised is the impact that a civionics system that uses conduit, junction boxes, and other electrical ancillary protection, will have when embedded and installed externally on full-scale infrastructure. The full-scale destructive testing of a second generation steel-free bridge deck using a civionics system designed and implemented following guidelines in a civioncs specification manual at the University of Manitoba will provide engineers with the information necessary to address the constructability and structural integrity issues. Civioncs combined with structural health monitoring will provide engineers with feedback necessary to aid in optimizing design techniques and understanding our infrastructures performance, behaviour and state of condition.

Performance and capacity assessment of reinforced concrete bridge piers considering the current load and resistance factor design provisions and plastic hinge length in Kansas : [technical summary].

DOT National Transportation Integrated Search

2014-05-01

Kansas Department of Transportation (KDOT) has implemented the new AASHTO : LRFD provisions in the state specific LRFD design procedure (KDOT-LRFD). There : have been some significant updates in new version of AASHTO-LRFD (2010), compared : to previo...

Rock mass classification system : transition from RMR to GSI.

DOT National Transportation Integrated Search

2013-11-01

The AASHTO LRFD Bridge Design Specifications is expected to replace the rock mass rating : (RMR) system with the Geological Strength Index (GSI) system for classifying and estimating : engineering properties of rock masses. This transition is motivat...

Enhancing the hermeneutic single-case efficacy design: Bridging the research-practice gap.

PubMed

Wall, Jessie M; Kwee, Janelle L; Hu, Monica; McDonald, Marvin J

2017-09-01

Systematic case study designs are emerging as alternative paradigm strategies for psychotherapy and social science research. Through enhanced sensitivity to context, these designs examine idiographic profiles of causal processes. We specifically advocate the use of the hermeneutic single-case efficacy design (HSCED). HSCED has recently been used to investigate the efficacy of an existing therapy with a new population (Observed and Experiential Integration for athlete performance barriers) and an emerging therapy (Lifespan Integration Therapy). We describe innovations in HSCED that were implemented for these studies. These developments include (a) integrating psychotherapists as case developers, (b) incorporating multiple cases in one investigation, and (c) tailoring the repertoire of assessment tools. These extensions strategically incorporated principles of contextual paradigms in HSCED, thus complementing single-case designs that neglect idiographic contexts. We discuss recommendations for using HSCED in practice-based research, highlighting its potential as a bridge to address the research-practice gap.

U.S. Geological Survey - Virginia Department of Transportation: Bridge scour pilot study

USGS Publications Warehouse

Austin, Samuel H.

2018-02-27

BackgroundCost effective and safe highway bridge designs are required to ensure the long-term sustainability of Virginia’s road systems. The streamflows that, over time, scour streambed sediments from bridge piers inherently affect bridge safety and design costs. To ensure safety, bridge design must anticipate streambed scour at bridge piers over the lifespan of a bridge. Until recently Federal Highway Administration (FHWA) guidance provided only for scour estimates of granular, noncohesive, highly erosive material yielding overestimates of scour potential in instances when streambed materials offer some resistance to scour. This study seeks to estimate stream power and streambed scour for these more resistive sites, with bridge piers potentially established in cohesive soil or erodible rock. This new knowledge may provide significant construction cost savings while ensuring design and construction of safe highway bridges.

49 CFR Appendix A to Part 237 - Supplemental Statement of Agency Policy on the Safety of Railroad Bridges

Code of Federal Regulations, 2014 CFR

2014-10-01

... for the design of a bridge can generally be used to determine and rate the load capacity of a bridge... from the service loads can be correlated to the stresses for which the bridge was designed or rated. 3... bridge should keep design, construction, maintenance and repair records readily accessible to permit the...

49 CFR Appendix A to Part 237 - Supplemental Statement of Agency Policy on the Safety of Railroad Bridges

Code of Federal Regulations, 2013 CFR

2013-10-01

... for the design of a bridge can generally be used to determine and rate the load capacity of a bridge... from the service loads can be correlated to the stresses for which the bridge was designed or rated. 3... bridge should keep design, construction, maintenance and repair records readily accessible to permit the...

49 CFR Appendix A to Part 237 - Supplemental Statement of Agency Policy on the Safety of Railroad Bridges

Code of Federal Regulations, 2010 CFR

2010-10-01

... for the design of a bridge can generally be used to determine and rate the load capacity of a bridge... from the service loads can be correlated to the stresses for which the bridge was designed or rated. 3... bridge should keep design, construction, maintenance and repair records readily accessible to permit the...

Design and introduction of a disulfide bridge in firefly luciferase: increase of thermostability and decrease of pH sensitivity.

PubMed

Imani, Mehdi; Hosseinkhani, Saman; Ahmadian, Shahin; Nazari, Mahboobeh

2010-08-01

The thermal sensitivity and pH-sensitive spectral properties of firefly luciferase have hampered its application in a variety of fields. It is proposed that the stability of a protein can be increased by introduction of disulfide bridge that decreases the configurational entropy of unfolding. A disulfide bridge is introduced into Photinus pyralis firefly luciferase to make two separate mutant enzymes with a single bridge. Even though the A103C/S121C mutant showed remarkable thermal stability, its specific activity decreased, whereas the A296C/A326C mutant showed tremendous thermal stability, relative pH insensitivity and 7.3-fold increase of specific activity. Moreover, the bioluminescence emission spectrum of A296C/A326C was resistant against higher temperatures (37 degrees C). Far-UV CD analysis showed slight secondary structure changes for both mutants. Thermal denaturation analysis showed that conformational stabilities of A103C/S121C and A296C/A326C are more than native firefly luciferase. It is proposed that since A296 and A326 are situated in the vicinity of the enzyme active site microenvironment in comparison with A103 and S121, the formation of a disulfide bridge in this region has more impact on enzyme kinetic characteristics.

75 FR 60438 - Record of Decision for the Guam and Commonwealth of Northern Mariana Islands Military Relocation...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-30

... expansion of the plant beyond the current design capacity of 12 MGd, improvements to the Northern and... improvements, bridge replacements, pavement strengthening at specific locations island-wide, and military...

Virtual Bridge Design Challenge

ERIC Educational Resources Information Center

Mitts, Charles R.

2013-01-01

This design/problem-solving activity challenges students to design a replacement bridge for one that has been designated as either structurally deficient or functionally obsolete. The Aycock MS Technology/STEM Magnet Program Virtual Bridge Design Challenge is an authentic introduction to the engineering design process. It is a socially relevant…

23 CFR 661.53 - What standards should be used for bridge design?

Code of Federal Regulations, 2011 CFR

2011-04-01

... 23 Highways 1 2011-04-01 2011-04-01 false What standards should be used for bridge design? 661.53... TRAFFIC OPERATIONS INDIAN RESERVATION ROAD BRIDGE PROGRAM § 661.53 What standards should be used for bridge design? (a) Replacement—A replacement structure must meet the current geometric, construction and...

23 CFR 661.53 - What standards should be used for bridge design?

Code of Federal Regulations, 2010 CFR

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false What standards should be used for bridge design? 661.53... TRAFFIC OPERATIONS INDIAN RESERVATION ROAD BRIDGE PROGRAM § 661.53 What standards should be used for bridge design? (a) Replacement—A replacement structure must meet the current geometric, construction and...

Design of piles for integral abutment bridges.

DOT National Transportation Integrated Search

1984-08-01

More and more, integral abutment bridges are being used in place : of the more traditional bridge designs with expansion releases. In : this study, states which use integral abutment bridges were surveyed : to determine their current practice in the ...

Electrical Rectification in Betaine Derivatives

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

Sumpter, Bobby G; Meunier, Vincent; Filho, Antonio G. Souza

2008-01-01

We theoretically investigate the electric rectification in an organic two terminal push-pull molecular device using a combination of ab initio techniques. Our main finding is that the electric rectification is extremely sensitive to the length of the chain, undergoing a complete switching after a specific chain length. This unique process occurs for betainelike donor- bridge-acceptor systems and is directly associated with a conjugated bridge in the presence of an external electric field. The conjugated bridge between the donor and acceptor groups is composed of oligoethylene with sizes ranging from zero to ten C=C units. The appearance of electric rectification occursmore » when the bridge size is equal to 5 units and is complete for those larger than 6 units (i.e. full inversion). This new electronic effect is advantageous for the design of large hybrid organic/inorganic circuits with anincreased majority carrier flow that is necessary for the emerging needs of nanotechnology.« less

Design, analysis, and seismic performance of a hypothetical seismically isolated bridge on legacy highway.

DOT National Transportation Integrated Search

2011-01-01

The need to maintain the functionality of critical transportation lifelines after a large seismic event motivates the : strategy to design certain bridges for performance standards beyond the minimum required by bridge design codes. : To design a bri...

Hydraulic modeling of mussel habitat at a bridge-replacement site, Allegheny River, Pennsylvania, USA

USGS Publications Warehouse

Fulton, John W.; Wagner, Chad R.; Rogers, Megan E.; Zimmerman, Gregory F.

2010-01-01

Based on the statistical targets established, the hydraulic model results suggest that an additional 2428 m2 or a 30-percent increase in suitable mussel habitat could be generated at the replacement-bridge site when compared to the baseline condition associated with the existing bridge at that same location. The study did not address the influences of substrate, acid mine drainage, sediment loads from tributaries, and surface-water/ground-water exchange on mussel habitat. Future studies could include methods for quantifying (1) channel–substrate composition and distribution using tools such as hydroacoustic echosounders specifically designed and calibrated to identify bed composition and mussel populations, (2) surface-water and ground-water interactions, and (3) a high-streamflow event.

Implementation of sustainability in bridge design, construction and maintenance.

DOT National Transportation Integrated Search

2012-12-01

The focus of this research is to develop a framework for more sustainable design and construction : processes for new bridges, and sustainable maintenance practices for existing bridges. The framework : includes a green rating system for bridges. The...

49 CFR 237.57 - Designations of individuals.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Designations of individuals. 237.57 Section 237.57... § 237.57 Designations of individuals. Each track owner shall designate those individuals qualified as railroad bridge engineers, railroad bridge inspectors and railroad bridge supervisors. Each individual...

Evaluation of CDOT specifications for class H and HT crack resistant concrete.

DOT National Transportation Integrated Search

2010-06-01

This study examined the performance of concrete mixtures designed to increase cracking resistance for Colorado bridge decks. The : current CDOT Class H and HT concrete mixtures and nine other mixtures were investigated to aid in the development of a ...

Implementation of sustainable and green design and construction practices for bridges.

DOT National Transportation Integrated Search

2012-12-01

The focus of this research is to develop a framework for more sustainable design and construction : processes for new bridges, and sustainable maintenance practices for existing bridges. The framework : includes a green rating system for bridges. The...

Discussion on design and stress checking of cast-in-place bracket

NASA Astrophysics Data System (ADS)

Xi, Tang Xian; Yong, He; Hu, Sun Shuan

2018-04-01

The cast-in-place bracket is the main support structure in the construction of bridge. Its strength, stiffness and stability have a direct impact on the quality and the safety of bridge construction. The design and calculation of the bracket in the prestressed concrete box girder are analyzed in this paper. The models including Bailey beam, steel crossbeam and steel columns are established by the finite element software. The strength, stiffness and stability of each model under the most unfavorable load are analyzed by MIDAS Civil. The analysis results verify that the support plan meets the relevant specifications and construction requirements. The feasibility of the support scheme was verified well accordingly. The paper can provide reference and guidance for similar engineering construction.

Towards a robust assessment of bridge clogging processes in flood risk management

NASA Astrophysics Data System (ADS)

Gschnitzer, T.; Gems, B.; Mazzorana, B.; Aufleger, M.

2017-02-01

River managers are aware that wood-clogging mechanisms frequently trigger damage-causing processes like structural damages at bridges, sudden channel outbursts, and occasionally, major displacements of the water course. To successfully mitigate flood risks related to the transport of large wood (LW), river managers need a guideline for an accurate and reliable risk assessment procedure and the design of river sections and bridges that are endangered of LW clogging. In recent years, comprehensive research dealing with the triggers of wood-clogging mechanisms at bridges and the corresponding impacts on flood risk was accomplished at the University of Innsbruck. A large set of laboratory experiments in a rectangular flume was conducted. In this paper we provide an overall view of these tests and present our findings. By applying a logistic regression analysis, the available knowledge on the influence of geometrical, hydraulic, and wood-related parameters on LW clogging probabilities is processed in a generalized form. Based on the experimental modeling results a practice-oriented guideline that supports the assessment of flood risk induced by LW clogging, is presented. In this context, two specific local structural protection measures at the bridge, aiming for a significant decrease of the entrapment probabilities, are illustrated: (i) a deflecting baffle installed on the upstream face of the bridge and (ii) a channel constriction leading to a change in flow state and a corresponding increase of the flow velocities and the freeboard at the bridge cross section. The presented guideline is based on a three-step approach: estimation of LW potential, entrainment, and transport; clogging scenario at the bridge; and the impact on channel and floodplain hydraulics. For a specific bridge susceptible to potential clogging caused by LW entrapment, it allows for a qualitative evaluation of potential LW entrainment in the upstream river segments, its transport toward the hydraulic bottleneck, and for a quantification of expected entrapment probabilities. Depending on the amount and characteristics of the impacting LW, consequences of bridge clogging can be determined and LW bridge-clogging scenarios can be considered within hydrodynamic numerical modeling.

Post-earthquake traffic capacity of modern bridges in California.

DOT National Transportation Integrated Search

2010-03-01

Evaluation of the capacity of a bridge to carry self-weight and traffic loads after an earthquake is essential for a safe and timely re-opening of the bridge. In California, modern highway bridges designed using the Caltrans Seismic Design Criteria a...

Post-Earthquake Traffic Capacity of Modern Bridges in California

DOT National Transportation Integrated Search

2010-03-01

Evaluation of the capacity of a bridge to carry self-weight and traffic loads after an earthquake is essential for a : safe and timely re-opening of the bridge. In California, modern highway bridges designed using the Caltrans : Seismic Design Criter...

New conceptual design of portable bamboo bridge for emergency purposes

NASA Astrophysics Data System (ADS)

Musthaffa, A. A.; Nor, N. M.; Yusof, M. A.; Yuhazri, M. Y.

2018-02-01

Portable bridges serve as routes for troops during the military operations and the disaster relief operation. Nowadays, bamboo has been regarded as one of the alternative construction materials for building and bridge structures. This paper presents the conceptual design of the portable bridge. Several types of portable bridges and bamboo bridges are reviewed in the current work. The characteristics, capability and method of construction of each bridge are discussed. Finally, the conceptual of the portable bamboo bridge for emergency purposes is presented. The idea of producing portable bridge is proposed in the current work as it is crucial for providing route for communities affected by natural disasters.

Reliability-based criteria for load and resistance factor design code for wood bridges

Treesearch

Chris Eamon; Andrzej S. Nowak; Michael A. Ritter; Joe Murphy

2000-01-01

Recently AASHTO adopted a load and resistance factor design code for highway bridges. The new code provides a rational basis for the design of steel and concrete structures. However, the calibration was not done for wood bridges. Therefore, there is a need to fill this gap. The development of statistical models for wood bridge structures is discussed. Recent test...

Bridge Workshop : Enhancing Bridge Performance, February 21-22, 2008, Reston, Virginia : workshop report

Treesearch

Sreenivas Alampalli; Sheila Rimal Duwadi; Reagan Sentelle Herman; Danielle D. Kleinhans; Khaled Mahmoud; James C. Ray; James P. Wacker; Nur Yazdani

2008-01-01

The participants to the workshop were given the charge to discuss (1) bridge design issues including best practices in design and detailing that could be used to improve durability, extend service life and prevent premature deterioration, (2) performance measures needed to better determine bridge condition, (3) technologies that could be used to monitor bridge life and...

The Contribution of Interchain Salt Bridges to Triple-Helical Stability in Collagen

PubMed Central

Gurry, Thomas; Nerenberg, Paul S.; Stultz, Collin M.

2010-01-01

Abstract Studies on collagen and collagen-like peptides suggest that triple-helical stability can vary along the amino acid chain. In this regard, it has been shown that lysine residues in the Y position and acidic residues in the X′ position of (GPO)3GXYGX′Y′(GPO)3 peptides lead to triple-helical structures with melting temperatures similar to (GPO)8 (where O is hydroxyproline), which is generally regarded as the most stable collagen-like sequence of this length. This enhanced stability has been attributed to the formation of salt bridges between adjacent collagen chains. In this study, we explore the relationship between interchain salt bridge formation and triple-helical stability using detailed molecular simulations. Although our results confirm that salt bridges promote triple-helical stability, we find that not all salt bridges are created equal. In particular, lysine-glutamate salt bridges are most stabilizing when formed between residues in the middle strand (B) and the trailing strand (C), whereas lysine-aspartate salt bridges are most stabilizing when formed between residues in the leading (A) and middle (B) strand—the latter observation being consistent with recent NMR data on a heterotrimeric model peptide. Overall, we believe these data clarify the role of salt bridges in modulating triple-helical stability and can be used to guide the design of collagen-like peptides that have specific interchain interactions. PMID:20513408

Reconfigurable wireless monitoring systems for bridges: validation on the Yeondae Bridge

NASA Astrophysics Data System (ADS)

Kim, Junhee; Lynch, Jerome P.; Zonta, Daniele; Lee, Jong-Jae; Yun, Chung-Bang

2009-03-01

The installation of a structural monitoring system on a medium- to large-span bridge can be a challenging undertaking due to high system costs and time consuming installations. However, these historical challenges can be eliminated by using wireless sensors as the primary building block of a structural monitoring system. Wireless sensors are low-cost data acquisition nodes that utilize wireless communication to transfer data from the sensor to the data repository. Another advantageous characteristic of wireless sensors is their ability to be easily removed and reinstalled in another sensor location on the same structure; this installation modularity is highlighted in this study. Wireless sensor nodes designed for structural monitoring applications are installed on the 180 m long Yeondae Bridge (Korea) to measure the dynamic response of the bridge to controlled truck loading. To attain a high nodal density with a small number (20) of wireless sensors, the wireless sensor network is installed three times with each installation concentrating sensors in one portion of the bridge. Using forced and free vibration response data from the three installations, the modal properties of the bridge are accurately identified. Intentional nodal overlapping of the three different sensor installations allows mode shapes from each installation to be stitched together into global mode shapes. Specifically, modal properties of the Yeondae Bridge are derived off-line using frequency domain decomposition (FDD) modal analysis methods.

Design and Synthesis of Novel Block Copolymers for Efficient Opto-Electronic Applications

NASA Technical Reports Server (NTRS)

Sun, Sam-Shajing; Fan, Zhen; Wang, Yiqing; Taft, Charles; Haliburton, James; Maaref, Shahin

2002-01-01

It has been predicted that nano-phase separated block copolymer systems containing electron rich donor blocks and electron deficient acceptor blocks may facilitate the charge carrier separation and migration in organic photovoltaic devices due to improved morphology in comparison to polymer blend system. This paper presents preliminary data describing the design and synthesis of a novel Donor-Bridge-Acceptor (D-B-A) block copolymer system for potential high efficient organic optoelectronic applications. Specifically, the donor block contains an electron donating alkyloxy derivatized polyphenylenevinylene (PPV), the acceptor block contains an electron withdrawing alkyl-sulfone derivatized polyphenylenevinylene (PPV), and the bridge block contains an electronically neutral non-conjugated aliphatic hydrocarbon chain. The key synthetic strategy includes the synthesis of each individual block first, then couple the blocks together. While the donor block stabilizes and facilitates the transport of the holes, the acceptor block stabilizes and facilitates the transport of the electrons, the bridge block is designed to hinder the probability of electron-hole recombination. Thus, improved charge separation and stability are expected with this system. In addition, charge migration toward electrodes may also be facilitated due to the potential nano-phase separated and highly ordered block copolymer ultra-structure.

Serviceability-related issues for bridge live load deflection and construction closure pours : [research summary].

DOT National Transportation Integrated Search

2015-06-01

The Load and Resistance Factor Design (LRFD) method has evolved to become a : more reliable approach to bridge design in the past century. Nevertheless, safety is : always the number one concern in the design of bridge structures. Equally important, ...

Safety Identifying of Integral Abutment Bridges under Seismic and Thermal Loads

PubMed Central

Easazadeh Far, Narges; Barghian, Majid

2014-01-01

Integral abutment bridges (IABs) have many advantages over conventional bridges in terms of strength and maintenance cost. Due to the integrity of these structures uniform thermal and seismic loads are known important ones on the structure performance. Although all bridge design codes consider temperature and earthquake loads separately in their load combinations for conventional bridges, the thermal load is an “always on” load and, during the occurrence of an earthquake, these two important loads act on bridge simultaneously. Evaluating the safety level of IABs under combination of these loads becomes important. In this paper, the safety of IABs—designed by AASHTO LRFD bridge design code—under combination of thermal and seismic loads is studied. To fulfill this aim, first the target reliability indexes under seismic load have been calculated. Then, these analyses for the same bridge under combination of thermal and seismic loads have been repeated and the obtained reliability indexes are compared with target indexes. It is shown that, for an IAB designed by AASHTO LRFD, the indexes have been reduced under combined effects. So, the target level of safety during its design life is not provided and the code's load combination should be changed. PMID:25405232

Software for AASHTO LRFD combined shear and torsion computations using modified compression field theory and 3D truss analogy.

DOT National Transportation Integrated Search

2011-10-01

The shear provisions of the AASHTO LRFD Bridge Design Specifications (2008), as well as the simplified : AASHTO procedure for prestressed and non-prestressed reinforced concrete members were investigated and compared : to their equivalent ACI 318-08 ...

Effects of increasing the allowable compressive stress at release on the shear strength of prestressed concrete girders.

DOT National Transportation Integrated Search

2008-09-01

In recent years, several research projects have been conducted to study the feasibility of increasing the allowable : compressive stress in concrete at prestress transfer, currently defined as 0.60f'ci in the AASHTO LRFD Bridge : Design Specification...

47 CFR 80.331 - Bridge-to-bridge communication procedure.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 5 2011-10-01 2011-10-01 false Bridge-to-bridge communication procedure. 80..., Alarm, Urgency and Safety Procedures § 80.331 Bridge-to-bridge communication procedure. (a) Vessels subject to the Bridge-to-Bridge Act transmitting on the designated navigational frequency must conduct...

47 CFR 80.331 - Bridge-to-bridge communication procedure.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Bridge-to-bridge communication procedure. 80..., Alarm, Urgency and Safety Procedures § 80.331 Bridge-to-bridge communication procedure. (a) Vessels subject to the Bridge-to-Bridge Act transmitting on the designated navigational frequency must conduct...

Computational Design Tool for Bridge Hydrodynamic Loading in Inundated Flows of Midwest Rivers

DOT National Transportation Integrated Search

2009-12-01

The hydraulic forces experienced by an inundated bridge deck have great importance in the design of bridges. The proper estimation of loading exerted by the flow on the structure is important for design plans and is pertinent for evaluating its vulne...

Design, installation, and condition assessment of a concrete bridge deck constructed with ASTM A1035 CS no. 4 bars.

DOT National Transportation Integrated Search

2017-06-01

Recently developed corrosion-resistant reinforcing structural design guidelines were used to design, construct, and : assess a reinforced concrete bridge deck with high-strength ASTM A1035 CS steel bars. The bridge replacement is located : along the ...

Design, construction and load testing of the bridge on Arnault Branch, Washington County, Missouri using innovative technologies.

DOT National Transportation Integrated Search

2010-02-01

The superstructure and instrumentation designs of a three-span bridge are presented in this report. The three spans include a : precast box-girder bridge, a precast deck on steel girder and a precast deck on concrete girder. They were designed to com...

Guardrails for use on historic bridges : volume 1--replacement strategies.

DOT National Transportation Integrated Search

2016-11-01

Bridges that are designated historic present a special challenge to bridge engineers whenever rehabilitation work or improvements are : made to the bridges. Federal and state laws protect historically significant bridges, and railings on these bridge...

Effects of Irregular Bridge Columns and Feasibility of Seismic Regularity

NASA Astrophysics Data System (ADS)

Thomas, Abey E.

2018-05-01

Bridges with unequal column height is one of the main irregularities in bridge design particularly while negotiating steep valleys, making the bridges vulnerable to seismic action. The desirable behaviour of bridge columns towards seismic loading is that, they should perform in a regular fashion, i.e. the capacity of each column should be utilized evenly. But, this type of behaviour is often missing when the column heights are unequal along the length of the bridge, allowing short columns to bear the maximum lateral load. In the present study, the effects of unequal column height on the global seismic performance of bridges are studied using pushover analysis. Codes such as CalTrans (Engineering service center, earthquake engineering branch, 2013) and EC-8 (EN 1998-2: design of structures for earthquake resistance. Part 2: bridges, European Committee for Standardization, Brussels, 2005) suggests seismic regularity criterion for achieving regular seismic performance level at all the bridge columns. The feasibility of adopting these seismic regularity criterions along with those mentioned in literatures will be assessed for bridges designed as per the Indian Standards in the present study.

Computational Fluid Dynamic Analysis of Hydrodynamic forces on inundated bridge decks

NASA Astrophysics Data System (ADS)

Afzal, Bushra; Guo, Junke; Kerenyi, Kornel

2010-11-01

The hydraulic forces experienced by an inundated bridge deck have great importance in the design of bridges. Flood flows or hurricane add significant hydrodynamic loading on bridges, possibly resulting in failure of the bridge superstructures. The objective of the study is to establish validated computational practice to address research needs of the transportation community via computational fluid dynamic simulations. The reduced scale experiments conducted at Turner-Fairbank Highway Research Center establish the foundations of validated computational practices to address the research needs of the transportation community. Three bridge deck prototypes were used: a typical six-girder highway bridge deck, a three-girder deck, and a streamlined deck designed to better withstand the hydraulic forces. Results of the study showed that the streamlined deck significantly reduces drag, lift, and moment coefficient in comparison to the other bridge deck types. The CFD results matched the experimental data in terms of the relationship between inundation ratio and force measured at the bridge. The results of the present research will provide a tool for designing new bridges and retrofitting old ones.

Influence of microclimate on the sustainability and reliability of weathering steel bridge

NASA Astrophysics Data System (ADS)

Kubzova, M.; Krivy, V.; Kreislova, K.

2018-04-01

Reliability and sustainability of bridge structures designed from weathering steel are influenced by the development of a sufficiently protective layer of corrosion products on its surface. The development of this protective layer is affected by several parameters such as air pollution around the bridge structure, the microclimate under the bridge, the location of surface within the bridge structure and the time of wetness. Design of structural details also significantly influences the development of the protective corrosion layer. The article deals with the results of the experimental tests carried out on the road bridge located in the city of Ostrava in the Czech Republic. The development of the protective corrosion layer on the surface of the bridge is significantly influenced by the intensive traffic under the bridge construction and the design solution of the bridge itself. Attention is focused mainly on the influence of chloride deposition on the protective function of the corrosion layer. Corrosion samples were placed on the bridge to evaluate the influence of the above-mentioned parameters. The deposition rate of chlorides spreading from the road to surfaces of the steel structure is also measured.

Bridges to Practice. A Research-Based Guide for Literacy Practitioners Serving Adults with Learning Disabilities.

ERIC Educational Resources Information Center

Academy for Educational Development, Washington, DC. National Adult Literacy and Learning Disabilities Center.

These five guidebooks are designed for literacy programs to enhance the quality of services provided to adults with learning disabilities. Each guidebook answers specific questions such as handling legal issues, screening for learning disabilities, selecting curriculum options, using effective instructional methods, and creating professional…

Software for AASHTO LRFD combined shear and torsion computations using modified compression field theory and 3D truss analogy : technical summary.

DOT National Transportation Integrated Search

2011-10-01

The shear provisions of the AASHTO LRFD Bridge Design Specifications (2008), as well as the simplified AASHTO procedure for prestressed and non-prestressed reinforced concrete members were investigated and compared to their equivalent ACI 318-08 prov...

Teaching Game Sense in Soccer

ERIC Educational Resources Information Center

Pill, Shane

2012-01-01

"Game sense" is a sport-specific iteration of the teaching games for understanding model, designed to balance physical development of motor skill and fitness with the development of game understanding. Game sense can foster a shared vision for sport learning that bridges school physical education and community sport. This article explains how to…

Plans for crash-tested bridge railings for longitudinal wood decks

Treesearch

M. A. Ritter; R. K. Faller; P. D. Hilbrich Lee; B. T. Rosson; S. R. Duwadi

1995-01-01

In the past decade, bridge railing design criteria have moved away from static-load design and have focused on full-scale crash testing as a more appropriate and reliable means of evaluating bridge railings. The five bridge railing plans presented reflect the results of a cooperative research project between the Midwest Roadside Safety Facility, University of Nebraska...

Iterating between Tools to Create and Edit Visualizations.

PubMed

Bigelow, Alex; Drucker, Steven; Fisher, Danyel; Meyer, Miriah

2017-01-01

A common workflow for visualization designers begins with a generative tool, like D3 or Processing, to create the initial visualization; and proceeds to a drawing tool, like Adobe Illustrator or Inkscape, for editing and cleaning. Unfortunately, this is typically a one-way process: once a visualization is exported from the generative tool into a drawing tool, it is difficult to make further, data-driven changes. In this paper, we propose a bridge model to allow designers to bring their work back from the drawing tool to re-edit in the generative tool. Our key insight is to recast this iteration challenge as a merge problem - similar to when two people are editing a document and changes between them need to reconciled. We also present a specific instantiation of this model, a tool called Hanpuku, which bridges between D3 scripts and Illustrator. We show several examples of visualizations that are iteratively created using Hanpuku in order to illustrate the flexibility of the approach. We further describe several hypothetical tools that bridge between other visualization tools to emphasize the generality of the model.

Microdevelopment during an activity-based science lesson

NASA Astrophysics Data System (ADS)

Parziale, Jim

1997-11-01

The purpose of this study was to describe the microdevelopment of task-related skills during a classroom science activity. Pairs of fifth and pairs of seventh grade students were videotaped as they constructed marshmallow and toothpick bridges. A skill theory based system of analysis was developed and used to detect the construction of new understandings. Patterns of change observed in these understandings were used to infer three means of self-construction: shifts of focus, bridging mechanisms and distributed cognition. Shift of focus is a mechanism used by students to efficiently explore a web of possibilities, collect ideas and make observations for later coordination as new understandings. Bridging mechanisms are partially built conversational structures that scaffolded the construction of higher level thinking structures. Students used the distributed cognition mechanism to test the adaptiveness of their design ideas without the need to fully coordinate an understandings of these designs. An integrated model of these three mechanisms is proposed specific to this task. This model describes how these mechanisms spontaneously emerged and interacted to support the construction of mental representations.

33 CFR Appendix B to Part 277 - Hypothetical Example of Cost Apportionment

Code of Federal Regulations, 2013 CFR

2013-07-01

...) $165,489 I b. Fixed charges (owner's share) 284,460 II A fixed charge such as engineering, design and... new bridge is designed for increased loading and width greater than that of the old bridge. Therefore, the estimated annual maintenance cost was based on a hypothetical bridge designed, but not constructed...

33 CFR Appendix B to Part 277 - Hypothetical Example of Cost Apportionment

Code of Federal Regulations, 2014 CFR

2014-07-01

...) $165,489 I b. Fixed charges (owner's share) 284,460 II A fixed charge such as engineering, design and... new bridge is designed for increased loading and width greater than that of the old bridge. Therefore, the estimated annual maintenance cost was based on a hypothetical bridge designed, but not constructed...

33 CFR Appendix B to Part 277 - Hypothetical Example of Cost Apportionment

Code of Federal Regulations, 2010 CFR

2010-07-01

...) $165,489 I b. Fixed charges (owner's share) 284,460 II A fixed charge such as engineering, design and... new bridge is designed for increased loading and width greater than that of the old bridge. Therefore, the estimated annual maintenance cost was based on a hypothetical bridge designed, but not constructed...

33 CFR Appendix B to Part 277 - Hypothetical Example of Cost Apportionment

Code of Federal Regulations, 2011 CFR

2011-07-01

...) $165,489 I b. Fixed charges (owner's share) 284,460 II A fixed charge such as engineering, design and... new bridge is designed for increased loading and width greater than that of the old bridge. Therefore, the estimated annual maintenance cost was based on a hypothetical bridge designed, but not constructed...

33 CFR Appendix B to Part 277 - Hypothetical Example of Cost Apportionment

Code of Federal Regulations, 2012 CFR

2012-07-01

...) $165,489 I b. Fixed charges (owner's share) 284,460 II A fixed charge such as engineering, design and... new bridge is designed for increased loading and width greater than that of the old bridge. Therefore, the estimated annual maintenance cost was based on a hypothetical bridge designed, but not constructed...

Combined seismic plus live-load analysis of highway bridges.

DOT National Transportation Integrated Search

2011-10-01

"The combination of seismic and vehicle live loadings on bridges is an important design consideration. There are well-established design : provisions for how the individual loadings affect bridge response: structural components that carry vertical li...

Comparative analysis of design codes for timber bridges in Canada, the United States, and Europe

Treesearch

James Wacker; James (Scott) Groenier

2010-01-01

The United States recently completed its transition from the allowable stress design code to the load and resistance factor design (LRFD) reliability-based code for the design of most highway bridges. For an international perspective on the LRFD-based bridge codes, a comparative analysis is presented: a study addressed national codes of the United States, Canada, and...

Protein thermal stability enhancement by designing salt bridges: a combined computational and experimental study.

PubMed

Lee, Chi-Wen; Wang, Hsiu-Jung; Hwang, Jenn-Kang; Tseng, Ching-Ping

2014-01-01

Protein thermal stability is an important factor considered in medical and industrial applications. Many structural characteristics related to protein thermal stability have been elucidated, and increasing salt bridges is considered as one of the most efficient strategies to increase protein thermal stability. However, the accurate simulation of salt bridges remains difficult. In this study, a novel method for salt-bridge design was proposed based on the statistical analysis of 10,556 surface salt bridges on 6,493 X-ray protein structures. These salt bridges were first categorized based on pairing residues, secondary structure locations, and Cα-Cα distances. Pairing preferences generalized from statistical analysis were used to construct a salt-bridge pair index and utilized in a weighted electrostatic attraction model to find the effective pairings for designing salt bridges. The model was also coupled with B-factor, weighted contact number, relative solvent accessibility, and conservation prescreening to determine the residues appropriate for the thermal adaptive design of salt bridges. According to our method, eight putative salt-bridges were designed on a mesophilic β-glucosidase and 24 variants were constructed to verify the predictions. Six putative salt-bridges leaded to the increase of the enzyme thermal stability. A significant increase in melting temperature of 8.8, 4.8, 3.7, 1.3, 1.2, and 0.7°C of the putative salt-bridges N437K-D49, E96R-D28, E96K-D28, S440K-E70, T231K-D388, and Q277E-D282 was detected, respectively. Reversing the polarity of T231K-D388 to T231D-D388K resulted in a further increase in melting temperatures by 3.6°C, which may be caused by the transformation of an intra-subunit electrostatic interaction into an inter-subunit one depending on the local environment. The combination of the thermostable variants (N437K, E96R, T231D and D388K) generated a melting temperature increase of 15.7°C. Thus, this study demonstrated a novel method for the thermal adaptive design of salt bridges through inference of suitable positions and substitutions.

Extreme Changes in Stream Geomorphic Conditions induced by Fluvial Scour in Bridges

NASA Astrophysics Data System (ADS)

Özcan, O.; Ozcan, O.

2016-12-01

The numerous complexities associated with bridge scour have caused scour to be one of the most active topics of stream geomorphic research. The assessment of local scouring mechanism around bridge piers provides information for decision-making regarding the pile footing design, predicting the safety of bridges under critical scoured conditions, and as a result, may help prevent unnecessary loses. In the study, bridge design plans and HEC-RAS modeling were used for the assessment of changes in stream geomorphic conditions. The derived fluvial scour depths were compared with the field measurements and the empirical formula which is based on stream flow discharge rate, streambed condition and shape of river. Preliminary results revealed that bridge damage resulting from the flood event in 2003 induced substantial scour around bridge piles. Afterwards, significant stream bed change was observed under the influence of fluvial scour in another flood occurred in 2009. Consequently, geomorphic conditions of the stream bed should be considered in the structural design of the bridges.

24. Photocopy of photograph appearing in August, 1928 issue of ...

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

24. Photocopy of photograph appearing in August, 1928 issue of the Reading Railroad Magazine. Caption reads: 'Harrisburg Division--Engine & Crew On A New Bridge Along the Steelton Branch.' From its appearance, this bridge (now demolished) is obviously another example of the Reading-Halls Bridge design. Note the bents used to support the trusses at points between the bridge abutments, enabling the bridge to carry loads far heavier than any it was designed to bear in the mid-nineteenth century. - Reading-Halls Station Bridge, U.S. Route 220, spanning railroad near Halls Station, Muncy, Lycoming County, PA

Geometry control of long-span continuous girder concrete bridge during construction through finite element model updating

NASA Astrophysics Data System (ADS)

Wu, Jie; Yan, Quan-sheng; Li, Jian; Hu, Min-yi

2016-04-01

In bridge construction, geometry control is critical to ensure that the final constructed bridge has the consistent shape as design. A common method is by predicting the deflections of the bridge during each construction phase through the associated finite element models. Therefore, the cambers of the bridge during different construction phases can be determined beforehand. These finite element models are mostly based on the design drawings and nominal material properties. However, the accuracy of these bridge models can be large due to significant uncertainties of the actual properties of the materials used in construction. Therefore, the predicted cambers may not be accurate to ensure agreement of bridge geometry with design, especially for long-span bridges. In this paper, an improved geometry control method is described, which incorporates finite element (FE) model updating during the construction process based on measured bridge deflections. A method based on the Kriging model and Latin hypercube sampling is proposed to perform the FE model updating due to its simplicity and efficiency. The proposed method has been applied to a long-span continuous girder concrete bridge during its construction. Results show that the method is effective in reducing construction error and ensuring the accuracy of the geometry of the final constructed bridge.

47 CFR 80.309 - Watch required by the Bridge-to-Bridge Act.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 5 2011-10-01 2011-10-01 false Watch required by the Bridge-to-Bridge Act. 80... Safety Watches § 80.309 Watch required by the Bridge-to-Bridge Act. In addition to the watch requirement contained in § 80.148, all vessels subject to the Bridge-to-Bridge Act must keep a watch on the designated...

47 CFR 80.309 - Watch required by the Bridge-to-Bridge Act.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Watch required by the Bridge-to-Bridge Act. 80... Safety Watches § 80.309 Watch required by the Bridge-to-Bridge Act. In addition to the watch requirement contained in § 80.148, all vessels subject to the Bridge-to-Bridge Act must keep a watch on the designated...

49 CFR 237.107 - Conduct of bridge inspections.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Conduct of bridge inspections. 237.107 Section 237... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.107 Conduct of bridge inspections. Bridge inspections shall be conducted under the direct supervision of a designated...

49 CFR 237.107 - Conduct of bridge inspections.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Conduct of bridge inspections. 237.107 Section 237... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.107 Conduct of bridge inspections. Bridge inspections shall be conducted under the direct supervision of a designated...

"Throughcare" for Drug-Using Prisoners in Britain: A Clinical Report

ERIC Educational Resources Information Center

Harman, Karen; Paylor, Ian

2004-01-01

CARAT (Counselling, Assessment, Referral, Advice and Throughcare) schemes have been operational in prisons throughout England and Wales for three and a half years, designed to increase the support available to drug-using prisoners both during custody and on release. Specifically the CARAT service has a remit to "bridge the gap" between…

Financial Coaching's Potential for Enhancing Family Financial Security

ERIC Educational Resources Information Center

Collins, J. Michael; Olive, Peggy; O'Rourke, Collin M.

2013-01-01

Financial coaching is an emerging complement to financial education and counseling. As defined in this article, financial coaching is a process whereby participants set goals, commit to taking certain actions by specific dates, and are then held accountable by the coach. In this way, financial coaching is designed to help participants bridge the…

Hmong High School Students in Afterschool: Effects on Achievement, Behavior, and Self-Esteem

ERIC Educational Resources Information Center

Boyer, Kimberley A. M.; Tracz, Susan M.

2014-01-01

Afterschool programs can support Asian-American young people by providing academic support and culturally specific programming designed to help them bridge their native and adopted cultures. However, little is known about the effect of afterschool participation on academic and social outcomes for Asian-American students. This causal-comparative…

Stem Cell Transplants (For Teens)

MedlinePlus

... help fight germs. Beta cells produce insulin to control sugars in our bodies. Melanocytes give skin its color. Most of the time, each cell has a specific job to do. One cell can't do what another cell can, just as a doctor isn't trained to design a bridge and an engineer can't do ...

Evaluation of design methods to determine scour depths for bridge structures : [technical summary].

DOT National Transportation Integrated Search

2013-01-01

Scour of bridge foundations is the most common cause of bridge failures. The Federal Highway Administration : (FHWA) has developed a design method, HEC-18, for the state Departments of Transportation (DOTs) to evaluate : the scour potential of existi...

Laboratory study - laboratory testing of bridge deck mixes

DOT National Transportation Integrated Search

2003-03-01

The purpose of this investigation was to develop bridge deck mixes that will improve field performance and minimize cracking potential compared to MoDOT's current (B-2) bridge deck mix design. The mix designs developed in this study were tested and c...

A Bridge to Active Learning: A Summer Bridge Program Helps Students Maximize Their Active-Learning Experiences and the Active-Learning Experiences of Others

ERIC Educational Resources Information Center

Cooper, Katelyn M.; Ashley, Michael; Brownell, Sara E.

2017-01-01

National calls to improve student academic success in college have sparked the development of bridge programs designed to help students transition from high school to college. We designed a 2-week Summer Bridge program that taught introductory biology content in an active-learning way. Through a set of exploratory interviews, we unexpectedly…

Serviceability-related issues for bridge live load deflection and construction closure pours.

DOT National Transportation Integrated Search

2015-06-01

This study investigated the design criteria and practices in an effort to improve the quality of bridge designs in the : State of Maryland and beyond. This first criterion investigated was the live load deflection for steel bridges. The : second desi...

Methods for removing concrete decks from bridge girders : [tech transfer summary].

DOT National Transportation Integrated Search

2014-08-01

Although bridges are typically designed to last for 75 years (AWS 2012), : bridge decks deteriorate at a faster rate (Flowers et al. 2010). Full-depth : replacement of bridge decks that can be performed without replacing the : bridge superstructures ...

Recommendations for design, construction, and maintenance of bridge approach slabs : synthesis report.

DOT National Transportation Integrated Search

2009-04-01

Bridge approaches provide smooth and safe transition of vehicles from highway pavements to bridge : structures. However, settlement of the bridge approach slab relative to bridge decks usually creates a : bump in the roadway. The bump causes inconven...

NCDOT : bridge policy

DOT National Transportation Integrated Search

1994-11-01

NCDOTs Bridge Policy establishes controlling design elements for new and reconstructed bridges on the state road system. It includes information to address sidewalks and bicycle facilities on bridges, including minimum handrail heights and sidewal...

Economic impact of multi-span, prestressed concrete girder bridges designed as simple span versus continuous span : final report.

DOT National Transportation Integrated Search

2016-10-01

The objective of this study was to determine the economic impact of designing pre-tensioned prestressed concrete beam (PPCB) : bridges utilizing the continuity developed in the bridge deck as opposed to the current Iowa Department of Transportation (...

Bridge approach slabs for Missouri DOT field evaluation of alternative and cost efficient bridge approach slabs.

DOT National Transportation Integrated Search

2013-05-01

Based on a recent study on cost efficient alternative bridge approach slab (BAS) designs (Thiagarajan et : al. 2010) has recommended three new BAS designs for possible implementation by MoDOT namely a) 20 feet cast-inplace : slab with sleeper slab (C...

Economic impact of multi-span, prestressed concrete girder bridges designed as simple span versus continuous span : tech transfer summary.

DOT National Transportation Integrated Search

2016-10-01

The objective of this study was to determine the economic impact of : designing pre-tensioned prestressed concrete beam (PPCB) bridges : utilizing the continuity developed in the bridge deck as opposed to the : current Iowa Department of Transportati...

49 CFR 237.55 - Railroad bridge supervisors.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Railroad bridge supervisors. 237.55 Section 237.55..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and Designations of Responsible Persons § 237.55 Railroad bridge supervisors. A railroad bridge supervisor shall be a person, regardless of...

49 CFR 237.55 - Railroad bridge supervisors.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Railroad bridge supervisors. 237.55 Section 237.55..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and Designations of Responsible Persons § 237.55 Railroad bridge supervisors. A railroad bridge supervisor shall be a person, regardless of...

A novel bridge scour monitoring and prediction system

NASA Astrophysics Data System (ADS)

Valyrakis, Manousos; Michalis, Panagiotis; Zhang, Hanqing

2015-04-01

Earth's surface is continuously shaped due to the action of geophysical flows. Erosion due to the flow of water in river systems has been identified as a key problem in preserving ecological health but also a threat to our built environment and critical infrastructure, worldwide. As an example, it has been estimated that a major reason for bridge failure is due to scour. Even though the flow past bridge piers has been investigated both experimentally and numerically, and the mechanisms of scouring are relatively understood, there still lacks a tool that can offer fast and reliable predictions. Most of the existing formulas for prediction of bridge pier scour depth are empirical in nature, based on a limited range of data or for piers of specific shape. In this work, the use of a novel methodology is proposed for the prediction of bridge scour. Specifically, the use of an Adaptive Neuro-Fuzzy Inference System (ANFIS) is proposed to estimate the scour depth around bridge piers. In particular, various complexity architectures are sequentially built, in order to identify the optimal for scour depth predictions, using appropriate training and validation subsets obtained from the USGS database (and pre-processed to remove incomplete records). The model has five variables, namely the effective pier width (b), the approach velocity (v), the approach depth (y), the mean grain diameter (D50) and the skew to flow. Simulations are conducted with data groups (bed material type, pier type and shape) and different number of input variables, to produce reduced complexity and easily interpretable models. Analysis and comparison of the results indicate that the developed ANFIS model has high accuracy and outstanding generalization ability for prediction of scour parameters. The effective pier width (as opposed to skew to flow) is amongst the most relevant input parameters for the estimation. Training of the system to new bridge geometries and flow conditions can be achieved by obtaining real time data, via novel electromagnetic sensors monitoring scour depth. Once the model is trained with data representative of the new system, bridge scour prediction can be performed for high/design flows or floods.

Demonstration of a roving-host wireless sensor network for rapid assessment monitoring of structural health

NASA Astrophysics Data System (ADS)

Mascarenas, David D. L.; Flynn, Eric; Lin, Kaisen; Farinholt, Kevin; Park, Gyuhae; Gupta, Rajesh; Todd, Michael; Farrar, Charles

2008-03-01

A major challenge impeding the deployment of wireless sensor networks for structural health monitoring (SHM) is developing means to supply power to the sensor nodes in a cost-effective manner. In this work an initial test of a roving-host wireless sensor network was performed on a bridge near Truth or Consequences, NM in August of 2007. The roving-host wireless sensor network features a radio controlled helicopter responsible for wirelessly delivering energy to sensor nodes on an "as-needed" basis. In addition, the helicopter also serves as a central data repository and processing center for the information collected by the sensor network. The sensor nodes used on the bridge were developed for measuring the peak displacement of the bridge, as well as measuring the preload of some of the bolted joints in the bridge. These sensors and sensor nodes were specifically designed to be able to operate from energy supplied wirelessly from the helicopter. The ultimate goal of this research is to ease the requirement for battery power supplies in wireless sensor networks.

Design of bridge deck drainage : HEC 21

DOT National Transportation Integrated Search

1993-05-01

The manual provides guidelines and procedures for designing bridge deck drainage systems, inclusing illustrative examples. Should the design process indicate a drainage system is needed, utilization of the most hydraulically efficient and maintenance...

Exploring our Country's History: Linking Fiction to Nonfiction. Literature Bridges to Social Studies Series.

ERIC Educational Resources Information Center

Perry, Phyllis J.

Fiction is a powerful tool that can motivate students to learn. This book is designed to assist elementary teachers in planning integrated units of study based on quality fiction titles about U.S. history. These titles build interest, illuminate specific eras, and lead students to related nonfiction titles. Organized in sections that cover…

Bridging the Great Divide: Connecting Alaska Native Learners and Leaders via "High Touch-High Tech" Distance Learning.

ERIC Educational Resources Information Center

Berkshire, Steven; Smith, Gary

The Rural Alaska Native Adult program of Alaska Pacific University is specifically designed for adult Native learners. Courses in business administration, human services, and teacher education are offered to rural Native adult students via an interactive Internet-based format after an initial 1-week residency. The Internet component is facilitated…

49 CFR 237.53 - Railroad bridge inspectors.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Railroad bridge inspectors. 237.53 Section 237.53..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and Designations of Responsible Persons § 237.53 Railroad bridge inspectors. A railroad bridge inspector shall be a person who is determined by...

Hierarchical analysis of bridge decision makers : the role of new technology adoption in the timber bridge market : special project fiscal year 1992

DOT National Transportation Integrated Search

1995-08-01

Bridge design engineers and local highway officials make bridge replacement decisions across the : United States. The Analytical Hierarchy Process was used to characterize the bridge material selection : decision of these individuals. State Departmen...

49 CFR 237.53 - Railroad bridge inspectors.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Railroad bridge inspectors. 237.53 Section 237.53..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and Designations of Responsible Persons § 237.53 Railroad bridge inspectors. A railroad bridge inspector shall be a person who is determined by...

High-frequency output characteristics of AlGaAs/GaAs heterojunction bipolar transistors for large-signal applications

NASA Astrophysics Data System (ADS)

Chen, J.; Gao, G. B.; Ünlü, M. S.; Morkoç, H.

1991-11-01

High-frequency ic- vce output characteristics of bipolar transistors, derived from calculated device cutoff frequencies, are reported. The generation of high-frequency output characteristics from device design specifications represents a novel bridge between microwave circuit design and device design: the microwave performance of simulated device structures can be analyzed, or tailored transistor device structures can be designed to fit specific circuit applications. The details of our compact transistor model are presented, highlighting the high-current base-widening (Kirk) effect. The derivation of the output characteristics from the modeled cutoff frequencies are then presented, and the computed characteristics of an AlGaAs/GaAs heterojunction bipolar transistor operating at 10 GHz are analyzed. Applying the derived output characteristics to microwave circuit design, we examine large-signal class A and class B amplification.

Design of footbridge with double curvature made of UHPC

NASA Astrophysics Data System (ADS)

Kněž, P.; Tej, P.; Čítek, D.; Kolísko, J.

2017-09-01

This paper presents design of footbridge with double curvature made of UHPC. The structure is designed as a single-span bridge. The span of the bridge is 10.00 m, and the width of the deck is 1.50 m. The thickness of shell structure is 0.03 m for walls and 0.045 m for deck. The main structure of the bridge is one arch shell structure with sidewalls made of UHPC with dispersed steel fibers with conventional reinforcement only at anchoring areas. The structure was designed on the basis of the numerical model. Model was subsequently clarified on the basis of the first test elements. Paper presents detailed course on design of the bridge and presentation will contain also installation in landscape and results of static and dynamic loading tests.

Bridge Structure, Foundation and Approach Embankment Performance for the October-November 2002 Earthquake Sequence on the Denali Fault, Alaska

NASA Astrophysics Data System (ADS)

Vinson, T. S.; Hulsey, L.; Ma, J.; Connor, B.; Brooks, T. E.

2002-12-01

More than two dozen major bridges were subjected to severe ground motions during the October-November 2002 Earthquake Sequence on the Denali Fault, Alaska. The bridges represented a number of conventional designs constructed over the past three to four decades. The objective of the field investigation presented herein was to determine the extent of the damage, if any, to the bridge structures, foundations and approach embankments. This was accomplished by direct inspection of the bridges by the authors (or employees of their organizations) along the Richardson, Alaska, Parks, and Denali Highways, the Tok Cutoff, and the railroad bridges for the railroad alignment between Trapper Creek and Fairbanks. More specifically, the members of the investigation team (represented by the authors) conducted more than three days of field inspections of bridges within the zone of severe ground shaking during the M6.7 and M7.9 Denali fault events. The primary conclusion noted was that while a substantial number of bridges were subjected to intense shaking they all performed very well and were not damaged to the extent that remedial repairs to the bridge structure were necessary. There were occurrences of lateral spreading/liquefaction related damage to the approach embankments and slight separation of the approach embankment from the abutment foundation systems. Overall, considering the severity of ground shaking, much greater damage to the bridge structures, foundations and approach embankments would be predicted. Had the earthquakes occurred during winter when the ground was frozen and the ductility of the structures was substantially reduced events comparable to the October-November 2002 Earthquake Sequence on the Denali Fault, Alaska could have resulted in significant damage to bridges. This reconnaissance was supported by the National Science Foundation, Alaska Dept. of Transportation and Public Facilities, and the Alaska Railroad Corporation.

Determination of barge impact probabilities for bridge design.

DOT National Transportation Integrated Search

2016-04-01

Waterway bridges in the United States are designed to resist vessel collision loads according to design provisions released by the American Association of State : Highway and Transportation Officials (AASHTO). These provisions provide detailed proced...

An evaluation of the systems approach to bridge design.

DOT National Transportation Integrated Search

1974-01-01

This study contains the findings from a survey of available integrated computer systems for bridge analysis and design, along with a sample design of a grade separation structure using the two leading design systems, BEST and STRC. It appears that in...

25 CFR 170.507 - Who reviews bridge inspection reports?

Code of Federal Regulations, 2011 CFR

2011-04-01

... 25 Indians 1 2011-04-01 2011-04-01 false Who reviews bridge inspection reports? 170.507 Section... ROADS PROGRAM Planning, Design, and Construction of Indian Reservation Roads Program Facilities Bridge Inspection § 170.507 Who reviews bridge inspection reports? The person responsible for the bridge inspection...

Effect of voids in grouted post-tensioned concrete bridge construction : inspection and repair manual for external tendons in segmental, post-tensioned bridges.

DOT National Transportation Integrated Search

2009-11-01

Segmental, post-tensioned (PT) bridges are major structures that carry significant traffic. These bridges are designed and constructed because they are economical for spanning long distances. In Texas, there are several signature PT bridges. In the l...

A Hierarchical Analysis of Bridge Decision Makers; the Role of New Technology Adoption in the Timber Bridge Market: Special Project Fiscal Year 1992

DOT National Transportation Integrated Search

1995-08-01

Bridge design engineers and local highway officials make bridge replacement decsions across the U.S. The Analytical Hierarchical Process was used to characterize the bridge material selection decisions of these individuals. State Departments of Trans...

Testing of New Bridge Rail and Transition Designs Vol. X APP.I; 42-in (1.07-m) Concrete Parapet Bridge Railing

DOT National Transportation Integrated Search

1997-06-01

This report presents the results of a State Planning and Research (SP&R) pooled-fund study to develop safer bridge rail and transition designs.This pooled-fund study was sponsored by the Federal Highway Administration, 23 States, and the District of ...

Kinetic bridges.

DOT National Transportation Integrated Search

1980-01-01

This report on kinetic bridges is essentially a state-of-the-art study on two types of bridges whose location or physical characteristics are designed to be time dependent. The first type, called a "relocatable bridge", is essentially for use as a te...

Simplified method for the transverse bending analysis of twin celled concrete box girder bridges

NASA Astrophysics Data System (ADS)

Chithra, J.; Nagarajan, Praveen; S, Sajith A.

2018-03-01

Box girder bridges are one of the best options for bridges with span more than 25 m. For the study of these bridges, three-dimensional finite element analysis is the best suited method. However, performing three-dimensional analysis for routine design is difficult as well as time consuming. Also, software used for the three-dimensional analysis are very expensive. Hence designers resort to simplified analysis for predicting longitudinal and transverse bending moments. Among the many analytical methods used to find the transverse bending moments, SFA is the simplest and widely used in design offices. Results from simplified frame analysis can be used for the preliminary analysis of the concrete box girder bridges.From the review of literatures, it is found that majority of the work done using SFA is restricted to the analysis of single cell box girder bridges. Not much work has been done on the analysis multi-cell concrete box girder bridges. In this present study, a double cell concrete box girder bridge is chosen. The bridge is modelled using three- dimensional finite element software and the results are then compared with the simplified frame analysis. The study mainly focuses on establishing correction factors for transverse bending moment values obtained from SFA.

Longevity of anterior resin-bonded bridges: survival rates of two tooth preparation designs.

PubMed

Abuzar, M; Locke, J; Burt, G; Clausen, G; Escobar, K

2018-04-16

Significant developments have occurred in the design of resin-bonded bridges (RBB) over the past two decades. They are commonly used as an alternative treatment option for a single missing tooth. The longevity of these bridges needs to be further investigated to evaluate long-term outcomes for this option to remain relevant. A cohort of patients who received anterior resin-bonded bridges (ARBB) over two decades was studied retrospectively. Longevity of 206 ARBB was assessed using Kaplan-Meier probability estimates. The two modified tooth preparation designs investigated were: (A) mesial and distal vertical grooves only; and (B) one proximal groove adjacent to the pontic and two palatal grooves. Age and gender of the patient cohort were also recorded. Overall survival rate of ARBB was 98% at 5 years, 97.2% at 10 years, and 95.1% from 12 years till 21 years. Survival curves showed minor differences when compared for the two designs, age groups and gender of ARBB recipients. Differences in the proportion of surviving bridges for design A (95.96%) and design B (98.13%) were not statistically significant (Fisher's exact test). Anterior RBB with described tooth preparation designs demonstrate a high survival rate. © 2018 Australian Dental Association.

Practical Nurses' Lived Experience of Returning to School.

PubMed

Chachula, Kathryn; Smith, Mary; Hyndman, Kathryn

2018-05-25

The lived experience of licensed practical nurses (LPNs) pursuing Bachelor of Nursing (BN) education is not commonly studied in Canada. The aim was to understand the transition experience of LPNs who bridged into a BN program. Max van Manen's phenomenological methodology was used through use of a semistructured interview guide to explore the lived experience of LPNs who pursued baccalaureate nursing education. Five themes were found: seeking advancement; stepping back into the student role; juggling work, school, and family; struggling to be understood; and seeing things differently. LPN-to-BN students have a well-developed sense of identity as nurses. These students can benefit from a specifically designed, stand-alone bridge course to situate them within a BN program.

Continuous prestressed concrete girder bridges volume 1 : literature review and preliminary designs.

DOT National Transportation Integrated Search

2012-06-01

The Texas Department of Transportation (TxDOT) is currently designing typical highway bridge structures as simply supported using standard precast, pretensioned girders. TxDOT is interested in developing additional economical design alternatives for ...

Long-term behavior of integral abutment bridges : [technical summary].

DOT National Transportation Integrated Search

2011-01-01

Integral abutment bridges, a type of jointless bridge, are the construction option of choice when designing highway bridges in many parts of the country. Rather than providing an expansion joint to separate the substructure from the superstructure to...

Standard Specifications for Construction of Roads and Bridges on Federal Highway Projects

DOT National Transportation Integrated Search

1996-01-01

These standard specifications were issued primarily for constructing roads and bridges on Federal Highway projects under the direct administration of the Federal Highway Administration. These specifications are cited as "FP-96" indicating Standard Sp...

Chesapeake City Bridge. Bridge Inspection Report Number 11B.

DTIC Science & Technology

1979-12-01

recommendations for th 1979 inspection of the Chesapeake City Bridge (Route designation , U.S. Route 213) which crosses the Chesappake and Delaware Canal...Los Arg4 .PASN4 . Mrkee. g14neaoos. Nevr,,r DE . Now York Oemnfto, overland PWn KS. Fh ~M% S0.mo- Tamp, TW=. F wia AMot ho d Jl 4O T, - kv Col. James G...1979 inspection of the Chesapeake City Bridge (Route designation , U.S. Route 213) which crosses the Chesapeake and Delaware Canal was undertaken for the

SSI-bridge : soil bridge interaction during long-duration earthquake motions.

DOT National Transportation Integrated Search

2014-09-01

The seismic response of a complete soil-bridge system during shallow, crustal and subduction zone earthquakes is the topic of this report. Specifically, the effects of earthquake duration on the seismic performance of soil-bridge systems are examined...

Long continuous bridge deck evaluation : John Day River Bridge, Clatsop County, Bridge No. 1827B : final report.

DOT National Transportation Integrated Search

1995-06-01

The John Day River Bridge, near Astoria, Oregon was built with a continuous deck length of 1,105 ft. (340 m). The rationale for designing the John Day River Bridge with an unusually long continuous deck is in part based on the site's very mild climat...

Experimental evaluation and design of unfilled and concrete-filled FRP composite piles, task 2 - FRP composite pile driving at the Richmond-Dresden bridge over the Kennebec River.

DOT National Transportation Integrated Search

2014-01-01

The overall goal of this project is the experimental evaluation and design of unfilled and concrete-filled FRP : composite piles for load-bearing in bridges. This report covers Task 2, FRP Composite Pile Driving at the : Richmond-Dresden Bridge over ...

Instrumentation of the US grant bridge for monitoring of fabrication, erection, in-service behavior, and to support management, maintenance, and inspection.

DOT National Transportation Integrated Search

2013-12-01

The replacement of the US Grant Bridge over the Ohio River in Portsmouth, OH, was initiated in : 2001 when the original bridge was closed and demolished, and its substitute opened in 2006. The : new design is a steel cable stay design with steel gird...

Multimedia package for LRFD concrete bridge design.

DOT National Transportation Integrated Search

2009-02-01

This Project developed a Load and Resistance Factor Design (LRFD) multimedia package to provide a practical introduction and an in-depth understanding of the technological advances in the design of concrete bridges. This package can be used to train ...

Aesthetic bridge rails, transitions, and terminals for park roads and parkways

DOT National Transportation Integrated Search

1990-05-01

The objective of this project was to test aesthetic bridge rails for park roads, parkways, and other roads under Federal jurisdiction. Four designs were analyzed and evaluated: the Modified (Kansas Corral bridge rail, the Forest Service glulam bridge...

Enhancement of welded steel bridge girders susceptible to distortion-induced fatigue : [technical summary].

DOT National Transportation Integrated Search

2014-10-01

Distortion-induced fatigue is a serious problem across the national bridge inventory, : affecting many steel bridges designed before the mid-1980s. Because distortion-induced : fatigue tends to develop in bridge connection details, near transverse el...

Simple model of cable-stayed bridge deck subjected to static wind loading

NASA Astrophysics Data System (ADS)

Kang, Yi-Lung; Wang, Yang Cheng

1997-05-01

Cable-stayed bridges have been known since 18th century with aesthetics design. The structural system and the structural behavior are significantly different from those of continuous bridges. Compared to continuous bridge, cable- stayed bridges have more flexure bridge deck than those of continuous bridges.On the other hand, cable-stayed bridges have less stiffness to resist wind loading especially for lateral loads. The first considering of bridge engineering is safety. In 1940's, Tacoma Narrows Suspension Bridge destroyed by wind loading is a good example even though it is not a cable-stayed bridge. After the bridge was destroyed, a lot of research articles have been published regarding cable supported bridge subjected to wind loading. In recent days, high strength materials have been served. The bridge engineers use the advantages to expand the span length of cable-stayed bridges. Due to the span length increased and the use of high strength materials, cable- stayed bridges have more significant nonlinear behavior subjected to wind loading. In this paper, a slice bridge deck of cable-stayed bridge connected to internal support cables is considered. The deck has been considered to be subjected to lateral static wind loading. Since cables can not take compressive force, the deck has strongly nonlinear behavior even though the materials are linear elastic. Several primary load combinations have ben considered in this paper such as the bridge deck supposed to be moved horizontally without rotation or the bridge deck supposed to be moved horizontally with rotational deformation. The mathematical formulas and the numerical solutions are found and represented in graphical forms. The results can be provided to bridge designers and researchers for further study of this type of structure subjected to wind loading.

Study on safety level of RC beam bridges under earthquake

NASA Astrophysics Data System (ADS)

Zhao, Jun; Lin, Junqi; Liu, Jinlong; Li, Jia

2017-08-01

This study considers uncertainties in material strengths and the modeling which have important effects on structural resistance force based on reliability theory. After analyzing the destruction mechanism of a RC bridge, structural functions and the reliability were given, then the safety level of the piers of a reinforced concrete continuous girder bridge with stochastic structural parameters against earthquake was analyzed. Using response surface method to calculate the failure probabilities of bridge piers under high-level earthquake, their seismic reliability for different damage states within the design reference period were calculated applying two-stage design, which describes seismic safety level of the built bridges to some extent.

A 1-2 GHz pulsed and continuous wave electron paramagnetic resonance spectrometer

NASA Astrophysics Data System (ADS)

Quine, Richard W.; Rinard, George A.; Ghim, Barnard T.; Eaton, Sandra S.; Eaton, Gareth R.

1996-07-01

A microwave bridge has been constructed that performs three types of electron paramagnetic resonance experiments: continuous wave, pulsed saturation recovery, and pulsed electron spin echo. Switching between experiment types can be accomplished via front-panel switches without moving the sample. Design features and performance of the bridge and of a resonator used in testing the bridge are described. The bridge is constructed of coaxial components connected with semirigid cable. Particular attention has been paid to low-noise design of the preamplifier and stability of automatic frequency control circuits. The bridge incorporates a Smith chart display and phase adjustment meter for ease of tuning.

Integration of a versatile bridge concept in a 34 GHz pulsed/CW EPR spectrometer

NASA Astrophysics Data System (ADS)

Band, Alan; Donohue, Matthew P.; Epel, Boris; Madhu, Shraeya; Szalai, Veronika A.

2018-03-01

We present a 34 GHz continuous wave (CW)/pulsed electron paramagnetic resonance (EPR) spectrometer capable of pulse-shaping that is based on a versatile microwave bridge design. The bridge radio frequency (RF)-in/RF-out design (500 MHz to 1 GHz input/output passband, 500 MHz instantaneous input/output bandwidth) creates a flexible platform with which to compare a variety of excitation and detection methods utilizing commercially available equipment external to the bridge. We use three sources of RF input to implement typical functions associated with CW and pulse EPR spectroscopic measurements. The bridge output is processed via high speed digitizer and an in-phase/quadrature (I/Q) demodulator for pulsed work or sent to a wideband, high dynamic range log detector for CW. Combining this bridge with additional commercial hardware and new acquisition and control electronics, we have designed and constructed an adaptable EPR spectrometer that builds upon previous work in the literature and is functionally comparable to other available systems.

Capacitance discharge system for ignition of Single Bridge Apollo Standard Initiators (SBASI)

NASA Technical Reports Server (NTRS)

Ward, R. D.

1974-01-01

The design support data developed during the single bridge Apollo standard initiator (SBASI) program are presented. A circuit was designed and bread-board tested to verify operational capabilities of the circuit. Test data, design criteria, weight, and reliability trade-off considerations, and final design recommendations are reported.

Frozen soil lateral resistance for the seismic design of highway bridge foundations : [summary].

DOT National Transportation Integrated Search

2012-12-01

With recent seismic activity and earthquakes in Alaska and throughout the Pacific Rim, seismic design is becoming an increasingly important public safety concern for : highway bridge designers. Hoping to generate knowledge that can improve the seismi...

Equivalent barge and flotilla impact forces on bridge piers.

DOT National Transportation Integrated Search

2008-06-01

Bridge piers located in navigable inland waterways are designed to resist impact forces from barges and flotillas in addition to other design considerations (e.g., scour, dead and live loads, etc.). The primary design tool for estimating these forces...

49 CFR 236.713 - Bridge, movable.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Bridge, movable. 236.713 Section 236.713 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Bridge, movable. That section of a structure bridging a navigable waterway so designed that it may be...

Evaluation of long-term prestress losses in post-tensioned box-girder bridges.

DOT National Transportation Integrated Search

2011-03-01

Most of the recent highway bridges built in California have post-tensioned, cast-in-place, concrete box-girder superstructures rigidly connected to bridge columns. However, methods provided in the current (2007 and 2010) AASHTO LRFD Bridge Design Spe...

Thermal gradients in Southwestern United States and the effect on bridge bearing loads : final report.

DOT National Transportation Integrated Search

2017-05-01

Thermal gradients became a component of bridge design after soffit cracking in prestressed concrete bridges was attributed to nonlinear temperature distribution through the depth of the bridge. While the effect of thermal gradient on stress distribut...

Laboratory investigation of grouted coupler connection details for ABC bridge projects.

DOT National Transportation Integrated Search

2015-08-01

With an ever increasing desire to utilize accelerated bridge construction (ABC) techniques, it is becoming critical that bridge : designers and contractors have confidence in typical details. The Keg Creek Bridge on US 6 in Iowa was a recent ABC exam...

Evaluation of design methods to determine scour depths for bridge structures.

DOT National Transportation Integrated Search

2013-03-01

Scour of bridge foundations is the most common cause of bridge failures. The overall goal of this project was to evaluate the applicability of the existing Hydraulic Engineering Circular (HEC-18) documents method to Louisiana bridges that are mostly ...

Long-term monitoring of the HPC Charenton Canal Bridge.

DOT National Transportation Integrated Search

2011-08-01

The report contains long-term monitoring data collection and analysis of the first fully high : performance concrete (HPC) bridge in Louisiana, the Charenton Canal Bridge. The design of this : bridge started in 1997, and it was built and opened to tr...

NHDOT : process for municipally-managed state bridge aid program projects

DOT National Transportation Integrated Search

2007-09-12

The document sets for the requirements for a municipality which to manage the design and construction of a bridge rehabilitation or replacement project and receive Bridge Aid under the applicable provisions of RSA 234. Bridge Aid provided to a Munici...

49 CFR 236.713 - Bridge, movable.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Bridge, movable. 236.713 Section 236.713 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Bridge, movable. That section of a structure bridging a navigable waterway so designed that it may be...

Bridge removal plan requirements.

DOT National Transportation Integrated Search

2011-04-15

This report provides resources that detail specifications and guidelines related to bridge removal plans across the : United States. We have organized the information into three sections: : ! National Guidance : Includes language from AASHTO specific...

A Hierarchical Analysis of Bridge Decision Makers ... The Role of New Technology Adoption in the Timber Bridge Market: Special Project

Treesearch

Robert L. Smith; Robert J. Bush; Daniel L. Schmoldt

1995-01-01

Bridge design engineers and local highway officials make bridge replacement decisions across the United States. The Analytical Hierarchy Process was used to characterize the bridge material selection decision of these individuals. State Department of Transportation engineers, private consulting engineers, and local highway officials were personally interviewed in...

Development of inspection robots for bridge cables.

PubMed

Yun, Hae-Bum; Kim, Se-Hoon; Wu, Liuliu; Lee, Jong-Jae

2013-01-01

This paper presents the bridge cable inspection robot developed in Korea. Two types of the cable inspection robots were developed for cable-suspension bridges and cable-stayed bridge. The design of the robot system and performance of the NDT techniques associated with the cable inspection robot are discussed. A review on recent advances in emerging robot-based inspection technologies for bridge cables and current bridge cable inspection methods is also presented.

Production of footbridge with double curvature made of UHPC

NASA Astrophysics Data System (ADS)

Kolísko, J.; Čítek, D.; Tej, P.; Rydval, M.

2017-09-01

This article present a mix design, preparation and production of thin-walled footbridge made from UHPFRC. In this case an experimental pedestrian bridge was design and prepared. Bridge with span of 10 m and the clear width of 1.50 m designed as single-span bridge. Optimization of UHPFRC matrix and parameters of this material leads to the design of very thin structures. Total thickness of shell structure 30 - 45 mm. Bridge was cast as a prefabricated element in one piece. Self-compacting character of UHPFRC with high flowability allows the production of the final structure. Extensive research was done before production of footbridge. Experimental reached data were compared with extensive numerical analysis and the final design of structure and UHPFRC matrix were optimized in many details. Two versions of large scale mock-ups were casted and tested. According to the complexity of whole experiment a casting technology and production of formwork were tested and optimized many times.

Design and implementation of the ESL compact range underhung bridge crane

NASA Technical Reports Server (NTRS)

Shamansky, H. T.; Dominek, A. K.; Burnside, W. D.

1987-01-01

As the indoor compact range technology has continued to increase, the need to handle larger and heavier targets has also increased. This need for target lifting and handling prompted the feasibility study of the use of an underhung bridge crane to be installed in the ESL (ElectroScience Laboratory, Ohio State University) compact range. This report documents both the design of the underhung bridge crane that was installed and the implementation of the design in the actual installation of the crane.

Performance evaluation of bridges with structural bridge deck overlays (SBDO).

DOT National Transportation Integrated Search

2006-03-01

Structural Bridge Deck Overlay (SBDO) involves applying 6 to 10 inches (150 to 200 mm) of normal weight, class AA, reinforced concrete directly to a bridges original slab. The overlay is designed to increase the deck elevation to an extent that st...

40 CFR 721.5880 - Sulfur bridged substituted phenols (generic name).

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Sulfur bridged substituted phenols... Specific Chemical Substances § 721.5880 Sulfur bridged substituted phenols (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance sulfur bridged...

40 CFR 721.5880 - Sulfur bridged substituted phenols (generic name).

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Sulfur bridged substituted phenols... Specific Chemical Substances § 721.5880 Sulfur bridged substituted phenols (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance sulfur bridged...

40 CFR 721.5880 - Sulfur bridged substituted phenols (generic name).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sulfur bridged substituted phenols... Specific Chemical Substances § 721.5880 Sulfur bridged substituted phenols (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance sulfur bridged...

40 CFR 721.5880 - Sulfur bridged substituted phenols (generic name).

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Sulfur bridged substituted phenols... Specific Chemical Substances § 721.5880 Sulfur bridged substituted phenols (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance sulfur bridged...

40 CFR 721.5880 - Sulfur bridged substituted phenols (generic name).

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Sulfur bridged substituted phenols... Specific Chemical Substances § 721.5880 Sulfur bridged substituted phenols (generic name). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance sulfur bridged...

Effect of voids in grouted, post-tensioned concrete bridge construction : volume 2--inspection, repair, materials, and risks.

DOT National Transportation Integrated Search

2009-09-01

Post-tensioned (PT) bridges are major structures that carry significant traffic. These bridges are designed and : constructed because they are economical for spanning long distances. In Texas, there are several signature PT : bridges. In the late 199...

Development of recommended resistance factors for drilled shafts in weak rocks based on o-cell tests.

DOT National Transportation Integrated Search

2010-03-01

From October 1, 2007, the new bridges on federal-aid funded projects are mandated to be designed to meet : American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design : (LRFD) Bridge Design Specificat...

Two test level 4 bridge railing and transition systems for transverse timber deck bridges

Treesearch

Ronald K. Faller; Michael A. Ritter; Barry T. Rosson; Michael D. Fowler; Sheila R. Duwadi

2000-01-01

The Midwest Roadside Safety Facility, in cooperation with the Forest Products Laboratory, which is part of the U.S. Department of Agricultureas Forest Service, and FHWA, designed two bridge railing and approach guardrail transition systems for use on bridges with transverse glue-laminated timber decks. The bridge raging and transition systems were developed and crash...

A New Multiconstraint Method for Determining the Optimal Cable Stresses in Cable-Stayed Bridges

PubMed Central

Asgari, B.; Osman, S. A.; Adnan, A.

2014-01-01

Cable-stayed bridges are one of the most popular types of long-span bridges. The structural behaviour of cable-stayed bridges is sensitive to the load distribution between the girder, pylons, and cables. The determination of pretensioning cable stresses is critical in the cable-stayed bridge design procedure. By finding the optimum stresses in cables, the load and moment distribution of the bridge can be improved. In recent years, different research works have studied iterative and modern methods to find optimum stresses of cables. However, most of the proposed methods have limitations in optimising the structural performance of cable-stayed bridges. This paper presents a multiconstraint optimisation method to specify the optimum cable forces in cable-stayed bridges. The proposed optimisation method produces less bending moments and stresses in the bridge members and requires shorter simulation time than other proposed methods. The results of comparative study show that the proposed method is more successful in restricting the deck and pylon displacements and providing uniform deck moment distribution than unit load method (ULM). The final design of cable-stayed bridges can be optimised considerably through proposed multiconstraint optimisation method. PMID:25050400

A new multiconstraint method for determining the optimal cable stresses in cable-stayed bridges.

PubMed

Asgari, B; Osman, S A; Adnan, A

2014-01-01

Cable-stayed bridges are one of the most popular types of long-span bridges. The structural behaviour of cable-stayed bridges is sensitive to the load distribution between the girder, pylons, and cables. The determination of pretensioning cable stresses is critical in the cable-stayed bridge design procedure. By finding the optimum stresses in cables, the load and moment distribution of the bridge can be improved. In recent years, different research works have studied iterative and modern methods to find optimum stresses of cables. However, most of the proposed methods have limitations in optimising the structural performance of cable-stayed bridges. This paper presents a multiconstraint optimisation method to specify the optimum cable forces in cable-stayed bridges. The proposed optimisation method produces less bending moments and stresses in the bridge members and requires shorter simulation time than other proposed methods. The results of comparative study show that the proposed method is more successful in restricting the deck and pylon displacements and providing uniform deck moment distribution than unit load method (ULM). The final design of cable-stayed bridges can be optimised considerably through proposed multiconstraint optimisation method.

Development of Inspection Robots for Bridge Cables

PubMed Central

Kim, Se-Hoon; Lee, Jong-Jae

2013-01-01

This paper presents the bridge cable inspection robot developed in Korea. Two types of the cable inspection robots were developed for cable-suspension bridges and cable-stayed bridge. The design of the robot system and performance of the NDT techniques associated with the cable inspection robot are discussed. A review on recent advances in emerging robot-based inspection technologies for bridge cables and current bridge cable inspection methods is also presented. PMID:24459453

Skewed highway bridges.

DOT National Transportation Integrated Search

2013-07-01

Many highway bridges are skewed and their behavior and corresponding design analysis need to be furthered to fully accomplish design objectives. This project used physical-test and detailed finite element analysis to better understand the behavior of...

Applications of microcomputers in bridge design.

DOT National Transportation Integrated Search

1986-01-01

The utilization of microcomputers in bridge design activities in state transportation departments was evaluated through contacts with 32 state agencies. While the present utilization of microcomputers was found to be limited, subsequent research show...

Phase II : correlation between experimental and finite element analysis : Alaska bridge 255-Chulitna River bridge.

DOT National Transportation Integrated Search

2014-09-01

In this study, we will monitor the behavior of the Alaska Chulitna Bridge for the specific purpose of assisting the DOT in performing an accurate : condition assessment of this bridge. : Based on the state-of-the-art SHM knowledge and technologies wi...

76 FR 78157 - Safety Zone; Eisenhower Expressway Bridge Rehabilitation Project; Chicago River South Branch...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-16

...-AA00 Safety Zone; Eisenhower Expressway Bridge Rehabilitation Project; Chicago River South Branch... the Eisenhower Expressway Bridge. This temporary safety zone is necessary to protect the surrounding... Bridge. Entry into this zone is prohibited unless specifically authorized by the Captain of the Port...

Long term monitoring of carbon composite strands in the Penobscot-Narrows bridge.

DOT National Transportation Integrated Search

2015-06-01

The Penobscot-Narrows Bridge was constructed between May 2003 and December 2006. The bridge is a cable-stayed design with twin pylons and a 2,120-foot span. This cable-stayed bridge features a cradle stay system that : allows for each cable strand in...

Approach for establishing approximate load carrying capacity for bridges with unknown material and unknown design properties.

DOT National Transportation Integrated Search

2011-07-01

There are 16 small to medium simple span bridges in Larimer County, Colorado that are currently load rated solely based on visual inspections. Most of these bridges are prestressed concrete bridges. The objective of this project is to load rate these...

Bridge inspector's manual for movable bridges.

DOT National Transportation Integrated Search

1977-01-01

Importance of Inspection-Movable bridges are built to the rigid specifications : of such groups as the American Association of State Highway and : Transportation Officials (AASHTO), the American Road Builders Association : (ARBA) and Underwriters Lab...

Development of recommended resistance factors for drilled shafts in weak rocks based on o-cell tests : [technical summary].

DOT National Transportation Integrated Search

2010-03-01

Since October 1st 2007, federal-funded projects including new bridges have been mandated to be designed to meet American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) Bridge Design Specifi...

A Methodology for Multihazards Load Combinations of Earthquake and Heavy Trucks for Bridges

PubMed Central

Wang, Xu; Sun, Baitao

2014-01-01

Issues of load combinations of earthquakes and heavy trucks are important contents in multihazards bridge design. Current load resistance factor design (LRFD) specifications usually treat extreme hazards alone and have no probabilistic basis in extreme load combinations. Earthquake load and heavy truck load are considered as random processes with respective characteristics, and the maximum combined load is not the simple superimposition of their maximum loads. Traditional Ferry Borges-Castaneda model that considers load lasting duration and occurrence probability well describes random process converting to random variables and load combinations, but this model has strict constraint in time interval selection to obtain precise results. Turkstra's rule considers one load reaching its maximum value in bridge's service life combined with another load with its instantaneous value (or mean value), which looks more rational, but the results are generally unconservative. Therefore, a modified model is presented here considering both advantages of Ferry Borges-Castaneda's model and Turkstra's rule. The modified model is based on conditional probability, which can convert random process to random variables relatively easily and consider the nonmaximum factor in load combinations. Earthquake load and heavy truck load combinations are employed to illustrate the model. Finally, the results of a numerical simulation are used to verify the feasibility and rationality of the model. PMID:24883347

The USGS National Streamflow Information Program and the importance of preserving long-term streamgages

USGS Publications Warehouse

Hodgkins, Glenn A.; Norris, J. Michael; Lent, Robert M.

2014-01-01

Long-term streamflow information is critical for use in several water-related areas that are important to humans and wildlife, including water management, computation of flood and drought flows for water infrastructure, and analysis of climate-related trends. Specific uses are many and diverse and range from informing water rights across state and international boundaries to designing dams and bridges.

Effect of portland cement (current ASTM C150/AASHTO M85) with limestone and process addition (ASTM C465/AASHTO M327) on the performance of concrete for pavement and bridge decks.

DOT National Transportation Integrated Search

2014-02-01

The Illinois Department of Transportation (IDOT) is making several changes to concrete mix designs, using revisions to : cement specification ASTM C150/AASHTO M85 and ASTM C465/AASHTO M327. These proposed revisions will enable the : use of more susta...

49 CFR 237.131 - Design.

Code of Federal Regulations, 2010 CFR

2010-10-01

... modification which materially modifies the capacity of a bridge or the stresses in any primary load-carrying... materially modify the capacity of a bridge or the stresses in any primary load-carrying component of a bridge...

49 CFR 237.131 - Design.

Code of Federal Regulations, 2012 CFR

2012-10-01

... modification which materially modifies the capacity of a bridge or the stresses in any primary load-carrying... materially modify the capacity of a bridge or the stresses in any primary load-carrying component of a bridge...

Strategic sensor locations of FPR bridge decks

NASA Astrophysics Data System (ADS)

Wu, Hwai-Chung; Warnemuende, Kraig; Yan, An; Mu, Bin

2003-07-01

Advanced fiber-reinforced polymer composite (FRP) has been increasingly used in bridge deck to replace concrete or steel. A FRP bridge deck can be designed to meet AASHTO HS-25 load requirements. FRP decks have many advantages over the conventional reinforced concrete or steel decks owing to their lightweight, high strength and corrosion resistance. However, such new deck system requires extensive monitoring to ensure its designed performance before its widespread acceptance by the bridge community. For inspection and evaluation purpose, a proper monitoring system consisting of various kinds of sensors installed in the FRP deck is critical. This paper provides a framework for designing an efficient monitoring system. The strategic sensor locations are identified based on the stress analysis of the FRP deck.

Integration of a versatile bridge concept in a 34 GHz pulsed/CW EPR spectrometer.

PubMed

Band, Alan; Donohue, Matthew P; Epel, Boris; Madhu, Shraeya; Szalai, Veronika A

2018-03-01

We present a 34 GHz continuous wave (CW)/pulsed electron paramagnetic resonance (EPR) spectrometer capable of pulse-shaping that is based on a versatile microwave bridge design. The bridge radio frequency (RF)-in/RF-out design (500 MHz to 1 GHz input/output passband, 500 MHz instantaneous input/output bandwidth) creates a flexible platform with which to compare a variety of excitation and detection methods utilizing commercially available equipment external to the bridge. We use three sources of RF input to implement typical functions associated with CW and pulse EPR spectroscopic measurements. The bridge output is processed via high speed digitizer and an in-phase/quadrature (I/Q) demodulator for pulsed work or sent to a wideband, high dynamic range log detector for CW. Combining this bridge with additional commercial hardware and new acquisition and control electronics, we have designed and constructed an adaptable EPR spectrometer that builds upon previous work in the literature and is functionally comparable to other available systems. Published by Elsevier Inc.

Evaluation of DOTD semi-integral bridge and abutment system.

DOT National Transportation Integrated Search

2005-03-01

The Louisiana Department of Transportation and Development (LADOTD) designed and constructed its first prototype semi-integral abutment bridge in 1989. In this design, large longitudinal movements due to expansion and contraction, creep, shrinkage, a...

Tolerable movement criteria for highway bridges, volume I : interim report.

DOT National Transportation Integrated Search

1982-09-01

"The design procedure presented considers both strength and serviceability criteria. The procedure involves designing a bridge assuming no settlement will take place, using the American Association of State Highway and Transportation Officials workin...

Determination of barge impact probabilities for bridge design : [summary].

DOT National Transportation Integrated Search

2016-04-01

University of Florida researchers developed a revised barge impact probability expression applicable for the design of bridge structures located on Florida waterways. University of Florida researchers obtained barge flotilla traffic data and barge-to...

T-section glulam timber bridge modules : modeling and performance

Treesearch

Paul A. Morgan; Steven E. Taylor; Michael A. Ritter; John M. Franklin

1999-01-01

This paper describes the design, modeling, and testing of two portable timber bridges, each consisting of two noninterconnected longitudinal glued-laminated timber (glulam) deck panels 1.8 m (6 ft) wide. One bridge is 12.2 m (40 ft) long while the other bridge is 10.7 m (35 ft) long. The deck panels are fabricated in a unique double-tee cross section. The bridges...

Bridge-Scour Data Management System user's manual

USGS Publications Warehouse

Landers, Mark N.; Mueller, David S.; Martin, Gary R.

1996-01-01

The Bridge-Scour Data Management System (BSDMS) supports preparation, compilation, and analysis of bridge-scour data. The BSDMS provides interactive storage, retrieval, selection, editing, and display of bridge-scour data sets. Bridge-scour data sets include more than 200 site and measurement attributes of the channel geometry, flow hydraulics, hydrology, sediment, geomorphic-setting, location, and bridge specifications. This user's manual provides a general overview of the structure and organization of BSDMS data sets and detailed instructions to operate the program. Attributes stored by the BSDMS are described along with an illustration of the input screen where the attribute can be entered or edited. Measured scour depths can be compared with scour depths predicted by selected published equations using the BSDMS. The selected published equations available in the computational portion of the BSDMS are described. This manual is written for BSDMS, version 2.0. The data base will facilitate: (1) developing improved estimators of scour for specific regions or conditions; (2) describing scour processes; and (3) reducing risk from scour at bridges. BSDMS is available in DOS and UNIX versions. The program was written to be portable and, therefore, can be used on multiple computer platforms. Installation procedures depend on the computer platform, and specific installation instructions are distributed with the software. Sample data files and data sets of 384 pier-scour measurements from 56 bridges in 14 States are also distributed with the software.

Investigating extreme event loading on coastal bridges using wireless sensor technology

NASA Astrophysics Data System (ADS)

Gelineau, Douglas A.; Davis, Justin R.; Rice, Jennifer A.

2017-04-01

Coastal infrastructure, such as bridges, are susceptible to many forms of coastal hazards: particularly hurricane surge and wave loading. These two forms of loading can cause catastrophic damage to aging highway infrastructure. It is estimated that storm damage costs the United States about $50 Billion per year. In light of this, it is crucial that we understand the damaging forces placed on infrastructure during storm events so that we can develop safer and more resilient coastal structures. This paper presents the ongoing research to enable the efficient collection of extreme event loads acting on both the substructure and superstructure of low clearance, simple span, reinforced concrete bridges. Bridges of this type were commonly constructed during the 1950's and 60's and are particularly susceptible to deck unseating caused by hurricane surge and wave loading. The sensing technology used to capture this data must be ruggedized to survive in an extremely challenging environment, be designed to allow for redundancy in the event of sensors or other network components being lost in the storm, and be relatively low cost to allow for more bridges to be instrumented per storm event. The prototype system described in this paper includes wireless technology, rapid data transmission, and, for the sensors, self-contained power. While this specific application focuses on hurricane hazards, the framework can be extended to include other natural hazards.

Seismic design guidelines for highway bridges

NASA Astrophysics Data System (ADS)

Mayes, R. L.; Sharpe, R. L.

1981-10-01

Guidelines for the seismic design of highway bridges are given. The guidelines are the recommendations of a team of nationally recognized experts which included consulting engineers, academicians, State highway, and Federal agency representatives from throughout the United States. The guidelines are comprehensive in nature and they embody several new concepts which are significant departures from existing design provisions. An extensive commentary documenting the basis for the guidelines and an example demonstrating their use are included. A draft of the guidelines was used to seismically redesign twenty-one bridges. A summary of the redesigns is included.

A Brillouin smart FRP material and a strain data post processing software for structural health monitoring through laboratory testing and field application on a highway bridge

NASA Astrophysics Data System (ADS)

Bastianini, Filippo; Matta, Fabio; Galati, Nestore; Nanni, Antonio

2005-05-01

Strain and temperature sensing obtained through frequency shift evaluation of Brillouin scattered light is a technology that seems extremely promising for Structural Health Monitoring (SHM). Due to the intrinsic distributed sensing capability, Brillouin can measure the deformation of any individual segment of huge lengths of inexpensive single-mode fiber. In addition, Brillouin retains other typical advantages of Fiber Optic Sensors (FOS), such as harsh environment durability and interference rejection. Despite these advantages, the diffusion of Brillouin for SHM is constrained by different factors, such as the high equipment cost, the commercial unavailability of specific SHM oriented fiber products and even some prejudices on the required sensitivity performances. In the present work, a complete SHM pilot application was developed, installed and successfully operated during a diagnostic load test on the High Performance Steel (HPS) bridge A6358 located at the Lake of the Ozarks (Miller County, MO, USA). Four out of five girders were extensively instrumented with a "smart" Glass Fiber Reinforced Polymer (GFRP) tape having embedded fibers for strain sensing and thermal compensation. Data collected during a diagnostic load test were elaborated through a specific post-processing software, and the strain profiles retrieved were compared to traditional strain gauges and theoretical results based on the AASHTO LRFD Bridge Design Specifications for structural assessment purposes. The excellent results obtained confirm the effectiveness of Brillouin SHM systems for the monitoring of real applications.

Performance specification for high performance concrete overlays on bridges.

DOT National Transportation Integrated Search

2004-01-01

Hydraulic cement concrete overlays are usually placed on bridges to reduce the infiltration of water and chloride ions and to improve skid resistance, ride quality, and surface appearance. Constructed in accordance with prescription specifications, s...

Bridge hosts for avian influenza viruses at the wildlife/domestic interface: an eco-epidemiological framework implemented in southern Africa.

PubMed

Caron, A; Grosbois, V; Etter, E; Gaidet, N; de Garine-Wichatitsky, M

2014-12-01

Wild terrestrial birds can act as potential local spreaders or bridge hosts for avian influenza viruses (AIVs) between waterfowl (the maintenance hosts of AIVs) and domestic avian populations in which AIVs may cause disease. Few studies have investigated this hypothesis, although it is an important knowledge gap in our understanding of AIV spread within socio-ecosystems. We designed a simple and reproducible approach in an agro-ecosystem in Zimbabwe based on: (1) bird counts at key target sites (i.e., wetlands, villages, intensive poultry production buildings and ostrich farms) to identify which wild birds species co-occur in these different sites and seasons when the risk of AIV transmission through these potential bridge hosts is maximal and (2) targeted sampling and testing for AIV infection in the identified potential bridge hosts. We found that 12 wild bird species represented the vast majority (79%) of co-occurrences in the different sites, whereas 230 bird species were recorded in this ecosystem. Specifically, three species - barn swallow, Hirundo rustica, red-billed quelea, Quelea quelea and cattle egret, Bubulcus ibis - represented the main potential bridge host species (65% of co-occurrences). In two out of these three species (i.e., barn swallow and red-billed quelea), we detected AIV infections, confirming that they can play a bridge function between waterfowl and domestic species in the ecosystem. Our approach can be easily implemented in other ecosystems to identify potential bridge hosts, and our results have implications in terms of surveillance, risk management and control of AIV spread in socio-ecosystems. Copyright © 2014 Elsevier B.V. All rights reserved.

Impact of overhang construction on girder design.

DOT National Transportation Integrated Search

2010-05-01

Economical constraints on the design of bridges usually necessitate the use of as few girders as possible across the : bridge width. The girders are typically uniformly spaced transversely with the deck extending past the fascia girders, thereby : re...

1. General view of bridge looking north. This is the ...

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

1. General view of bridge looking north. This is the only suspension bridge in Cleveland. It was designed by Wilbur J. Watson and Associates, Consulting Engineers. Sections of the Wooden deck are missing, and the bridge is no longer used. - Sidaway Avenue Footbridge, Jackowo & Garden Valley neighborhood Vicinity, Cleveland, Cuyahoga County, OH

Impact of the Shodan Computer Search Engine on Internet-facing Industrial Control System Devices

DTIC Science & Technology

2014-03-27

bridge implementation. The transparent bridge is designed using a Raspberry Pi configured with Linux IPtables and bridge-utils to bridge the on board...Ethernet card and a second USB Ethernet adapter. A Raspberry Pi is a credit-card-sized single-board computer running a version of Debian Linux. There

Laboratory and field testing of an accelerated bridge construction demonstration bridge : US Highway 6 bridge over Keg Creek : tech transfer summary.

DOT National Transportation Integrated Search

2013-04-01

To address the need for the development of a fast, repeatable, and dependable way to replace typical bridges across the country, the Transportation Research Board (TRB) developed project R04, Innovative Designs for Rapid Renewal, as part of the...

Building Better Bridges into STEM: A Synthesis of 25 Years of Literature on STEM Summer Bridge Programs

ERIC Educational Resources Information Center

Ashley, Michael; Cooper, Katelyn M.; Cala, Jacqueline M.; Brownell, Sara E.

2017-01-01

Summer bridge programs are designed to help transition students into the college learning environment. Increasingly, bridge programs are being developed in science, technology, engineering, and mathematics (STEM) disciplines because of the rigorous content and lower student persistence in college STEM compared with other disciplines. However, to…

Evaluation of the environmental impact of bridge deck runoff.

DOT National Transportation Integrated Search

2012-12-01

Bridges are located in very close proximity to receiving waters, and regulatory agencies often require specific stormwater : control measures for bridge deck runoff. While there is some information available on roadway runoff, few studies have : focu...

Design and Characterization of a Peptide Mimotope of the HIV-1 gp120 Bridging Sheet

PubMed Central

Schiavone, Marco; Fiume, Giuseppe; Caivano, Antonella; de Laurentiis, Annamaria; Falcone, Cristina; Masci, Francesca Fasanella; Iaccino, Enrico; Mimmi, Selena; Palmieri, Camillo; Pisano, Antonio; Pontoriero, Marilena; Rossi, Annalisa; Scialdone, Annarita; Vecchio, Eleonora; Andreozzi, Concetta; Trovato, Maria; Rafay, Jan; Ferko, Boris; Montefiori, David; Lombardi, Angela; Morsica, Giulia; Poli, Guido; Quinto, Ileana; Pavone, Vincenzo; de Berardinis, Piergiuseppe; Scala, Giuseppe

2012-01-01

The Bridging Sheet domain of HIV-1 gp120 is highly conserved among the HIV-1 strains and allows HIV-1 binding to host cells via the HIV-1 coreceptors. Further, the bridging sheet domain is a major target to neutralize HIV-1 infection. We rationally designed four linear peptide epitopes that mimic the three-dimensional structure of bridging sheet by using molecular modeling. Chemically synthesized peptides BS3 and BS4 showed a fair degree of antigenicity when tested in ELISA with IgG purified from HIV+ broadly neutralizing sera while the production of synthetic peptides BS1 and BS2 failed due to their high degree of hydrophobicity. To overcome this limitation, we linked all four BS peptides to the COOH-terminus of GST protein to test both their antigenicity and immunogenicity. Only the BS1 peptide showed good antigenicity; however, no envelope specific antibodies were elicited upon mice immunization. Therefore we performed further analyses by linking BS1 peptide to the NH2-terminus of the E2 scaffold from the Geobacillus Stearothermophylus PDH complex. The E2-BS1 fusion peptide showed good antigenic results, however only one immunized rabbit elicited good antibody titers towards both the monomeric and oligomeric viral envelope glycoprotein (Env). In addition, moderate neutralizing antibodies response was elicited against two HIV-1 clade B and one clade C primary isolates. These preliminary data validate the peptide mimotope approach as a promising tool to obtain an effective HIV-1 vaccine. PMID:22754323

12. DETAIL VIEW OF BRIDGE, SHOWING SPRING LINE OF SPANS ...

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

12. DETAIL VIEW OF BRIDGE, SHOWING SPRING LINE OF SPANS FROM CROWN OF MID-CHANNEL PIER, PAIRED COLUMNS SUPPORTING DECK, ARCHED WINDOW RAILING, LOOKING WEST-NORTHWEST FROM EUREKA SOUTHERN RAILROAD BRIDGE. CABLES VISIBLE IN BACKGROUND ARE EARTHQUAKE RESTRAINERS RETROFITTED TO 1952 HIGHWAY BRIDGE, WHICH FUNCTIONED AS DESIGNED IN APRIL 1992 TEMBLOR - Van Duzen River Bridge, Spanning Van Duzen River at CA State Highway 101, Alton, Humboldt County, CA

Fatigue evaluation for Tsing Ma Bridge using structural health monitoring data

NASA Astrophysics Data System (ADS)

Chan, Hung-tin Tommy; Ko, Jan Ming; Li, Zhao-Xia

2001-08-01

Fatigue assessment for the Tsing Ma Bridge (TMB) are presented based on the British standard BS5400 and the real-time structural health monitoring data under railway loading. TMB, as an essential portion of transport network for the Hong Kong airport, is the longest suspension bridge in the world carrying both highway and railway traffic. The bridge design has been mainly based on BS5400. A structural health monitoring system - Wind and Structural Health Monitoring System (WASHMS) for TMB has been operated since the bridge commissioning in May 1997. In order to assess the fatigue behavior of TMB under railway loading, strain gauges were installed on the bridge deck to measure the strain-time histories as soon as the bridge is loaded by a standard railway loading due to the service of an actual train. The strain-time history data at the critical members are then used to determine the stress spectrum, of which the rainflow method recommended for railway bridges by BS5400 is applied to count cycles of stress range. Miner's law is employed to evaluate fatigue damage and remaining service life of the bridge. The evaluated results of fatigue damage and remaining service life would help us to well understand about the fatigue design of the bridge and status in fatigue accumulation.

Investigation of mechanistic deterioration modeling for bridge design and management.

DOT National Transportation Integrated Search

2017-04-01

The ongoing deterioration of highway bridges in Colorado dictates that an effective method for allocating limited management resources be developed. In order to predict bridge deterioration in advance, mechanistic models that analyze the physical pro...

Field study of an integral backwall bridge : final report.

DOT National Transportation Integrated Search

1996-01-01

Integral bridges offer reduced maintenance expenditures, primarily due to the elimination of deck expansion joints. The design of an integral bridge, however, is complicated by the soil-structure interaction associated with thermal movements. It has ...

Guidelines For The Use, Design, And Construction Of Bridge Approach Slabs

DOT National Transportation Integrated Search

1999-11-01

Differential settlement at the roadway/bridge interface typically results in an abrupt grade change, causing driver discomfort impairing driver safety, and exerting potentially excessive impact traffic loading on the abutment. Bridge approach slabs a...

Design procedure for Bridge Foundations Subject to Liquefaction-Induced Lateral Spreading

DOT National Transportation Integrated Search

2017-04-01

The response of piled bridge foundations to liquefaction-induced lateral soil deformation is an important design consideration in seismically active regions. Recent research and case history data suggest that three-dimensional deformation of the appr...

Bridge scour and stream instability countermeasures : experience, selection, and design guidance : third edition. Volume 1

DOT National Transportation Integrated Search

2009-09-01

This document identifies and provides design guidelines for bridge scour and stream instability countermeasures that have been implemented by various State departments of transportation (DOTs) in the United States. Countermeasure experience, selectio...

Bridge scour and stream instability countermeasures : experience, selection, and design guidance : third edition. Volume 2

DOT National Transportation Integrated Search

2009-09-01

This document identifies and provides design guidelines for bridge scour and stream instability countermeasures that have been implemented by various State departments of transportation (DOTs) in the United States. Countermeasure experience, selectio...

Design and construction guidelines for strengthening bridges using fiber reinforced polymers (FRP).

DOT National Transportation Integrated Search

2014-09-01

This research concerns the development of guidelines : for the design and use of externally-bonded FRP : strengthening systems on bridges in Michigan. Si : x representative international FRP-related guidelines : were analyzed and compared for applica...

An evaluation of bridge deck joint sealing systems in Virginia.

DOT National Transportation Integrated Search

2003-01-01

The design and fabrication of bridge expansion joint (or movement) systems comprise a rapidly evolving industry. New designs are constantly being presented for trial, often on a piecemeal basis. Occasionally, failures of products occur without suffic...

Proof testing a bridge deck design with glass fiber reinforced polymer bars as top mat of reinforcement.

DOT National Transportation Integrated Search

2003-01-01

The primary objective of this project was to test a full-scale prototype of a bridge deck design containing glass fiber reinforced polymer (GFRP) bars as the top mat of reinforcement. The test deck mimics the design of the deck of one span of the new...

Evaluation of high temperature superconductive thermal bridges for space-borne cryogenic infrared detectors

NASA Technical Reports Server (NTRS)

Scott, Elaine P.

1993-01-01

The focus of this research is on the reduction of the refrigeration requirements for infrared sensors operating in space through the use of high temperature superconductive (HTS) materials as electronic leads between the cooled sensors and the relatively warmer data acquisition components. Specifically, this initial study was directed towards the design of an experiment to quantify the thermal performance of these materials in the space environment. First, an intensive review of relevant literature was undertaken, and then, design requirements were formulated. From this background information, a preliminary experimental design was developed. Additional studies will involve a thermal analysis of the experiment and further modifications of the experimental design.

Evaluation of fleet management techniques for timber highway bridges

Treesearch

Brent M. Phares; Travis K. Hosteng; Justin Dahlberg; Michael A. Ritter

2011-01-01

The general condition of the nation's bridges presents a complex management issue when considering cost, safety, and time. Consequently, the management of those bridges can become an overwhelming task. The need for a management system that is specific to rural systems may help to improve the management of this significant number of bridges. Although individual...

Construction of crack-free bridge decks : technical summary.

DOT National Transportation Integrated Search

2017-04-01

The report documents the performance of the decks based on crack surveys performed on the LC-HPC decks and : matching control bridge decks. The specifications for LC-HPC bridge decks, which cover aggregates, concrete, : and construction procedures, a...

Overload truck wheel load distribution on bridge decks.

DOT National Transportation Integrated Search

2009-04-01

There is a need to accurately analyze the load effects on bridge decks from permitted overload trucks on : Michigans roads. The AASHTO Standard Specifications for Highway Bridges, 17th edition, provides a : distribution width of live loads when re...

Investigation, Modeling and Validation of Digital Bridge for a New Generation Hot-Wire Anemometer

NASA Astrophysics Data System (ADS)

Joshi, Karthik Kamalakar

The Digital Bridge Thermal Anemometer (DBTA) is a new generation anemometer that uses advanced electronics and a modified half-Wheatstone bridge configuration, specifically a sensor and a shunt resistor in series. This allows the miniaturization of the anemometer and the communication between host computer and anemometer is carried out using serial or ethernet which eliminates the noise due to the use of long cables in conventional anemometer and the digital data sent to host computer is immune to electrical noise. In the new configuration the potential drop across a shunt resistor is used to control the bridge. This thesis is confined to the anemometer used in constant temperature (CT) mode. The heat transfer relations are studied and new expressions are developed based on the new configuration of the bridge using perturbation analysis. The theoretical plant model of a commercially available sensor and a custom built sensor are derived and quantified. The plant model is used to design a controller to control the plant in closed-loop using feedback. To test the performance of the modified sensor used with a "generation-I" bridge and DAQ, an experiment was conducted. The controller was implemented in a user interface in LabVIEW. The test is to compare the results between a conventional TSI sensor with an IFA 300 anemometer and the setup describe above, in the wake behind a circular cylinder. Performance of the DBTA is satisfactory at low frequencies. A user interface capable of communicating with the anemometer to control the operation and collect data generated by anemometer is developed in LabVIEW.

Connecticut permanent long-term bridge monitoring network, volume 1 : monitoring of post-tensioned segmental concrete box-girder bridge - I-95 over the Connecticut River in Old Saybrook (bridge #6200).

DOT National Transportation Integrated Search

2014-08-01

This report describes the instrumentation and data acquisition for an eleven span segmental, post-tensioned : box-girder bridge in Connecticut. Based on a request from the designers, the computer-based remote : monitoring system was developed to coll...

Overview of the National Timber Bridge Inspection Study

Treesearch

James P. Wacker; Brian K. Brashaw; Frank Jalinoos

2013-01-01

As many engineers begin to implement life cycle cost analyses within the preliminary bridge design phase, there is a significant need for more reliable data on the expected service life of highway bridges. Many claims are being made about the expected longevity of concrete and steel bridges, but few are based on actual performance data. Because engineers are least...

Breaking down Barriers: A Bridge Program Helps First-Year Biology Students Connect with Faculty

ERIC Educational Resources Information Center

Cooper, Katelyn M.; Ashley, Michael; Brownell, Sara E.

2018-01-01

Summer bridge programs often aim to build social connections for first-year students to ease their transition into college, yet few studies have reported on bridge programs successfully leading to these outcomes. We backward designed a summer bridge program for incoming biology majors to increase the comfort and connections among students and…

Initial investigation of reinforced concrete filled tubes for use in bridge foundations.

DOT National Transportation Integrated Search

2012-06-01

The Washington State Department of Transportation (WSDOT) frequently employs deep pile or caisson bridge : foundations for its bridge structures. Deep pile and drilled shaft foundations are increasingly important for seismic : design in Washington st...

Reduction of Bridge Deck Cracking through Alternative Material Usage

DOT National Transportation Integrated Search

2017-12-01

ODOT routinely deploys a large number of continuous span structural slab bridges. Despite being designed to strictly satisfy all the relevant AASHTO and ODOT BDM requirements, many such bridge decks show transverse cracks, with widths greater than th...

Object Markers at Narrow Bridges on Low Volume Rural Roadways

DOT National Transportation Integrated Search

1998-09-01

Bridges are a necessary part of any roadway system. Their construction requires a more sophisticated engineering design analysis and a higher construction cost than that for the roadways connecting them. Until relatively recently, bridge width on low...

Rapid replacement/construction of bridges.

DOT National Transportation Integrated Search

2012-11-01

Bridges are a key element of the transportation system because they control system capacity and are normally built at : the highest cost to the system. Once a bridge reaches its useful design service life, it needs to be replaced or : reconstructed i...

Research notes : base isolation bearings hold up.

DOT National Transportation Integrated Search

2003-05-01

Existing bridges, such as the Marquam Bridge in Portland, are given seismic retrofits, and new bridges are designed to more demanding seismic standards. Other structures may have a seismic device built in. The ODOT Research Unit has monitored one suc...

Determining the effective system damping of highway bridges.

DOT National Transportation Integrated Search

2009-06-01

This project investigates four methods for modeling modal damping ratios of short-span and isolated : concrete bridges subjected to strong ground motion, which can be used for bridge seismic analysis : and design based on the response spectrum method...

Design considerations for bridge deck joint-sealing systems : summary report.

DOT National Transportation Integrated Search

1992-07-01

This is a report summary which summarizes a three year research effort related to the study of bridge deck expansion joint movements. Bridge deck expansion joint systems often develop serious problems requiring extensive and expensive maintenance. Th...

Recommendations for design, construction, and maintenance of bridge approach slabs.

DOT National Transportation Integrated Search

2012-09-01

Settlement and heave related movements of bridge approach slabs relative to bridge decks create a bump in : the roadway. Several problems arise from these bumps, which include poor riding conditions, potential : vehicle damage, loss of vehicle contro...

Unmanned surface vessel (USV) systems for bridge inspection : final report.

DOT National Transportation Integrated Search

2016-08-01

The use of unmanned surface vehicles (USVs) for bridge inspection has been explored. The following issues were considered: (1) the requirements of and : current techniques utilized in on-water bridge inspection; (2) USV design and configuration consi...

Abrasion-resistant concrete mix designs for precast bridge deck panels.

DOT National Transportation Integrated Search

2010-08-01

The report documents laboratory investigations undertaken to develop high performance concrete (HPC) for precast and pre-stressed bridge deck components that would reduce the life-cycle cost of bridges by improving the studded tire wear (abrasion) re...

Salt bridge as a gatekeeper against partial unfolding.

PubMed

Hinzman, Mark W; Essex, Morgan E; Park, Chiwook

2016-05-01

Salt bridges are frequently observed in protein structures. Because the energetic contribution of salt bridges is strongly dependent on the environmental context, salt bridges are believed to contribute to the structural specificity rather than the stability. To test the role of salt bridges in enhancing structural specificity, we investigated the contribution of a salt bridge to the energetics of native-state partial unfolding in a cysteine-free version of Escherichia coli ribonuclease H (RNase H*). Thermolysin cleaves a protruding loop of RNase H(*) through transient partial unfolding under native conditions. Lys86 and Asp108 in RNase H(*) form a partially buried salt bridge that tethers the protruding loop. Investigation of the global stability of K86Q/D108N RNase H(*) showed that the salt bridge does not significantly contribute to the global stability. However, K86Q/D108N RNase H(*) is greatly more susceptible to proteolysis by thermolysin than wild-type RNase H(*) is. The free energy for partial unfolding determined by native-state proteolysis indicates that the salt bridge significantly increases the energy for partial unfolding by destabilizing the partially unfolded form. Double mutant cycles with single and double mutations of the salt bridge suggest that the partially unfolded form is destabilized due to a significant decrease in the interaction energy between Lys86 and Asp108 upon partial unfolding. This study demonstrates that, even in the case that a salt bridge does not contribute to the global stability, the salt bridge may function as a gatekeeper against partial unfolding that disturbs the optimal geometry of the salt bridge. © 2016 The Protein Society.

Structural design guidelines for concrete bridge decks reinforced with corrosion-resistant reinforcing bars.

DOT National Transportation Integrated Search

2014-10-01

This research program develops and validates structural design guidelines and details for concrete bridge decks with : corrosion-resistant reinforcing (CRR) bars. A two-phase experimental program was conducted where a control test set consistent : wi...

Performance of a skewed semi-integral bridge : volume 1 : field monitoring.

DOT National Transportation Integrated Search

2008-01-01

This project was developed to enhance the Virginia Department of Transportation's (VDOT) in-house expertise in the design of integral bridges and to provide a resource for consultants performing design work for VDOT. It involved extensive field monit...

Field demonstration of new bridge approach slab designs and performance.

DOT National Transportation Integrated Search

2014-06-01

The Louisiana Department of Transportation and Development (DOTD) has initiated a major effort to minimize the bridge end bump problem associated : with differential settlement. As a result, a new design for the approach slab was proposed, which requ...

Numerical investigation into thermal load responses of steel railway bridge

NASA Astrophysics Data System (ADS)

Saravana Raja Mohan, K.; Sreemathy, J. R.; Saravanan, U.

2017-07-01

Bridge design requires consideration of the effects produced by temperature variations and the resultant thermal gradients in the structure. Temperature fluctuation leads to expansion and contraction of bridges and these movements are taken care by providing expansion joints and bearings. Free movements of a member can be restrained by imposing certain boundary condition but at the same time considerable allowances should be made for the stresses resulting from this restrained condition since the additional deformations and stresses produced may affect the ultimate and serviceability limit states of the structure. If the reaction force generated by the restraints is very large, then its omission can lead to unsafe design. The principal objective of this research is to study the effects of temperature variation on stresses and deflection in a steel railway bridge. A numerical model, based on finite element analysis is presented for evaluating the thermal performance of the bridge. The selected bridge is analyzed and the temperature field distribution and the corresponding thermal stresses and strains are calculated using the finite element software ABAQUS. A thorough understanding of the thermal load responses of a structure will result in safer and dependable design practices.

TandemHeart as a Bridge to Recovery in Legionella Myocarditis.

PubMed

Briceño, David F; Fernando, Rajeev R; Nathan, Sriram; Loyalka, Pranav; Kar, Biswajit; Gregoric, Igor D

2015-08-01

Legionnaires' disease is the designation for pneumonia caused by the Legionella species. Among the rare extrapulmonary manifestations, cardiac involvement is most prevalent, in the forms of myocarditis, pericarditis, postcardiotomy syndrome, and prosthetic valve endocarditis. Mechanical circulatory support has proved to be a safe and effective bridge to myocardial recovery in patients with acute fulminant myocarditis; however, to our knowledge, this support has not been used in infectious myocarditis specifically related to Legionellosis. We describe a case of Legionella myocarditis associated with acute left ventricular dysfunction and repolarization abnormalities in a 48-year-old man. The patient fully recovered after left ventricular unloading with use of a TandemHeart percutaneous ventricular assist device. In addition, we review the English-language medical literature on Legionella myocarditis and focus on cardiac outcomes.

Fundamentals of bridge maintenance and inspection : manual for a workshop on bridge maintenance/inspection

DOT National Transportation Integrated Search

1997-07-01

This manual supplements the New York State Department of Transportation's one-day workshop on "Bridge Maintenance/Inspection." More specifically, it is intended as a handy reference for preventive-maintenance and corrective-maintenance activities app...

Evaluation of seismic design spectrum based on UHS implementing fourth-generation seismic hazard maps of Canada

NASA Astrophysics Data System (ADS)

Ahmed, Ali; Hasan, Rafiq; Pekau, Oscar A.

2016-12-01

Two recent developments have come into the forefront with reference to updating the seismic design provisions for codes: (1) publication of new seismic hazard maps for Canada by the Geological Survey of Canada, and (2) emergence of the concept of new spectral format outdating the conventional standardized spectral format. The fourth -generation seismic hazard maps are based on enriched seismic data, enhanced knowledge of regional seismicity and improved seismic hazard modeling techniques. Therefore, the new maps are more accurate and need to incorporate into the Canadian Highway Bridge Design Code (CHBDC) for its next edition similar to its building counterpart National Building Code of Canada (NBCC). In fact, the code writers expressed similar intentions with comments in the commentary of CHBCD 2006. During the process of updating codes, NBCC, and AASHTO Guide Specifications for LRFD Seismic Bridge Design, American Association of State Highway and Transportation Officials, Washington (2009) lowered the probability level from 10 to 2% and 10 to 5%, respectively. This study has brought five sets of hazard maps corresponding to 2%, 5% and 10% probability of exceedance in 50 years developed by the GSC under investigation. To have a sound statistical inference, 389 Canadian cities are selected. This study shows the implications of the changes of new hazard maps on the design process (i.e., extent of magnification or reduction of the design forces).

IPACS Electronics: Comments on the Original Design and Current Efforts at Langley Research Center

NASA Technical Reports Server (NTRS)

Gowdey, J. C.

1983-01-01

The development of the integrated power altitude control system (IPACS) is described. The power bridge was fabricated, and all major parts are in hand. The bridge was tested with a 1/4 HP motor for another program. The PWM, Control Logic, and upper bridge driver power supply are breadboarded and are debugged prior to starting testing on a passive load. The Hall sensor circuit for detecting rotor position is in design.

Connection details for prefabricated bridge elements and systems.

DOT National Transportation Integrated Search

2009-03-30

Prefabricated components of a bridge produced off-site can be assembled quickly, and can reduce design time and cost, minimizing forming, minimize lane closure time and/or possibly eliminate the need for a temporary bridge. This document has been dev...

Design and performance verification of UHPC piles for deep foundations.

DOT National Transportation Integrated Search

2008-11-01

The strategic plan for bridge engineering issued by AASHTO in 2005 identified extending the service life and optimizing structural : systems of bridges in the United States as two grand challenges in bridge engineering, with the objective of producin...

Integral abutment bridge for Louisiana's soft and stiff soils.

DOT National Transportation Integrated Search

2016-03-01

Integral abutment bridges (IABs) have been designed and constructed in a few US states in the past few : decades. The initial purpose of building such bridges was to eliminate the expansion joints and resolve the : joint-induced problems. Although IA...

Theoretical and field experimental evaluation of skewed modular slab bridges : [research summary].

DOT National Transportation Integrated Search

2012-12-01

Adjacent precast, prestressed concrete multi-beam bridges have become more : prevalent due to their rapid construction time and cost effectiveness. Over the : years, various adjustments and refinements have been made to the design of : these bridges ...

INVESTIGATION OF SEISMIC PERFORMANCE AND DESIGN OF TYPICAL CURVED AND SKEWED BRIDGES IN COLORADO

DOT National Transportation Integrated Search

2018-01-15

This report summarizes the analytical studies on the seismic performance of typical Colorado concrete bridges, particularly those with curved and skewed configurations. A set of bridge models with different geometric configurations derived from a pro...

Effect of implementing lean-on bracing in skewed steel I-girder bridges.

DOT National Transportation Integrated Search

2016-09-01

Skew of the supports in steel I-girder bridges cause undesirable torsional effects, increase cross-frame forces, and generally increase the difficulty of designing and : constructing a bridge. The girders experience differential deflections due to th...

Innovative concrete bridging systems for pedestrian bridges : implementation and monitoring.

DOT National Transportation Integrated Search

2013-08-01

Two precast, prestressed pedestrian bridges were designed for rapid construction in Rolla, MO, utilizing high-strength concrete (HSC) : and high-strength self-consolidating concrete (HS-SCC) with a target 28 day compressive strength of 68.9 MPa (10,0...

Prediction and mitigation of scour and scour damage to Vermont bridges.

DOT National Transportation Integrated Search

2017-02-20

Over 300 Vermont bridges were damaged in the 2011 Tropical Storm Irene and many experienced significant scour. Successfully mitigating bridge scour in future flooding events depends on our ability to reliably estimate scour potential, design safe and...

Design Optimization of Hybrid FRP/RC Bridge

NASA Astrophysics Data System (ADS)

Papapetrou, Vasileios S.; Tamijani, Ali Y.; Brown, Jeff; Kim, Daewon

2018-04-01

The hybrid bridge consists of a Reinforced Concrete (RC) slab supported by U-shaped Fiber Reinforced Polymer (FRP) girders. Previous studies on similar hybrid bridges constructed in the United States and Europe seem to substantiate these hybrid designs for lightweight, high strength, and durable highway bridge construction. In the current study, computational and optimization analyses were carried out to investigate six composite material systems consisting of E-glass and carbon fibers. Optimization constraints are determined by stress, deflection and manufacturing requirements. Finite Element Analysis (FEA) and optimization software were utilized, and a framework was developed to run the complete analyses in an automated fashion. Prior to that, FEA validation of previous studies on similar U-shaped FRP girders that were constructed in Poland and Texas is presented. A finer optimization analysis is performed for the case of the Texas hybrid bridge. The optimization outcome of the hybrid FRP/RC bridge shows the appropriate composite material selection and cross-section geometry that satisfies all the applicable Limit States (LS) and, at the same time, results in the lightest design. Critical limit states show that shear stress criteria determine the optimum design for bridge spans less than 15.24 m and deflection criteria controls for longer spans. Increased side wall thickness can reduce maximum observed shear stresses, but leads to a high weight penalty. A taller cross-section and a thicker girder base can efficiently lower the observed deflections and normal stresses. Finally, substantial weight savings can be achieved by the optimization framework if base and side-wall thickness are treated as independent variables.

Development of steel design details and selection criteria for cost effective and innovative steel bridges in Colorado : CDOT study no. 85-00 final report.

DOT National Transportation Integrated Search

2011-07-01

This research focuses on finding a method for creating cost effective and innovative steel bridges in Colorado. The design method that was discovered to create this cost efficiency was designing the beams as simply supported for non-composite dead lo...

Shear test of high performance steel hybrid girders.

DOT National Transportation Integrated Search

2005-06-01

High performance steel (HPS) has been used in hundreds of bridges in the United States. A large percentage of these bridges have used HPS in the form of hybrid girder design. One limit with hybrid girder design, which decreases the beneficial aspects...

Design and evaluation of a single-span bridge using ultra-high performance concrete.

DOT National Transportation Integrated Search

2009-09-01

"Research presented herein describes an application of a newly developed material called Ultra-High Performance Concrete (UHPC) to a : single-span bridge. The two primary objectives of this research were to develop a shear design procedure for possib...

Design and evaluation of a single-span bridge using ultra-high performance concrete.

DOT National Transportation Integrated Search

2009-09-01

Research presented herein describes an application of a newly developed material called Ultra-High Performance Concrete (UHPC) to a : single-span bridge. The two primary objectives of this research were to develop a shear design procedure for possibl...

Field evaluation of alternative and cost efficient bridge approach slabs.

DOT National Transportation Integrated Search

2013-11-01

Based on a recent study on cost efficient alternative bridge approach slab (BAS) designs (Thiagarajan et al. 2010) has recommended : three new BAS designs for possible implementation by MoDOT namely a) 20 feet cast-inplace slab with sleeper slab (CIP...

78 FR 76387 - Notice of Passenger Facility Charge (PFC) Approvals and Disapprovals

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-17

... Collection and Use: Security enhancements. Rehabilitate runway. Snow removal equipment--broom. Design and... Collection and Use: Snow removal equipment acquisition (broom). Terminal jet bridge modification (design). Pavement condition index maintenance update. Taxilane construction/conversion. Terminal jet bridge and gate...

Performance and design of bridge approach panels in Wisconsin.

DOT National Transportation Integrated Search

2015-02-01

Within the recent past, the Wisconsin DOT changed the bridge approach slab design from a system using only one expansion joint to a system using three expansion joints. This change was due primarily to the need to accommodate differential expansion a...

Implementation of a pilot continuous monitoring system : Iowa Falls Arch Bridge : [tech transfer summary].

DOT National Transportation Integrated Search

2015-06-01

As part of designing, constructing, and maintaining the bridge infrastructure in : Iowa, the Iowa Department of Transportation (DOT) has, in recent years, focused : efforts on investigating the use of new high-performance materials, new design : conc...

Rational and Safe Design of Concrete Transportation Structures for Size Effect and Multi-Decade Sustainability

DOT National Transportation Integrated Search

2012-10-01

The overall goal of this project was to improve the safety and sustainability in the design of large : prestressed concrete bridges and other transportation structures. The safety of large concrete : structures, including bridges, has been insufficie...

Species Identification and Design Value Estimation of Wooden Members in Covered Bridges

Treesearch

Alex C. Wiedenhoeft; David E. Kretschmann

2014-01-01

Covered timber bridges are historic structures with unique aesthetic value. To preserve this value and maintain bridges in service, robust evaluation of their performance and safety is necessary. The strength of the timber found in covered bridges can vary considerably, not only because of age and condition, but also because of species and grade. For the practicing...

21. RAILROAD, RR. BRIDGE MISSISSIPPI, CLAY CO., WAVERLY 1.5 mi. ...

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

21. RAILROAD, RR. BRIDGE MISSISSIPPI, CLAY CO., WAVERLY 1.5 mi. S of Ms. 50 Proposed 218-foot turn span, design #2339 of Virginia Bridge and Iron Co., Roanoke, Va. 13 May 1914. Act. size: 16x11 in. Credit: Columbus & Greenville RR, Columbus, Ms. Sarcone Photography, Columbus, Ms. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

Field performance of timber bridges. 11, Spearfish Creek stress-laminated box-beam bridge

Treesearch

J. P. Wacker; M. A. Ritter; K. Stanfill-McMillan

The Spearfish Creek bridge was constructed in 1992 in Spearfish, South Dakota. It is a single-span, stress-laminated, box-beam superstructure. Performance of the bridge is being monitored for 5 years, beginning at installation. This report summarizes results for the first 3-1/2 years of monitoring and includes information on the design, construction, and field...

77 FR 50929 - Security Zones; 2012 RNC Bridge Security Zones, Captain of the Port St. Petersburg Zone, Tampa, FL

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-23

...-AA87 Security Zones; 2012 RNC Bridge Security Zones, Captain of the Port St. Petersburg Zone, Tampa, FL... temporary security zones around certain bridges on the waters of Pinellas County and Tampa Bay, Florida..., or mooring on waters within 50 yards of the designated bridges during the times that the security...

Site specific wave parameters for Texas coastal bridges : final report.

DOT National Transportation Integrated Search

2010-04-01

There are about 20 coastal bridges located in hurricane evacuation routes in the State of Texas that are : vulnerable to hurricane surge and wave action. Damage to these bridges could hamper emergency response : and other services, and also cause tre...

Evaluation of concrete bridge mix designs for control of cracking, phase I.

DOT National Transportation Integrated Search

2014-11-01

Cracking of concrete is a common problem with concrete structures such as bridge decks, pavements and bridge : rail. The Agency of Transportation (VTrans) has recently invested in higher performing concrete mixes that are : more impervious and has hi...

Feasibility of tubular fender units for pier protection against vessel collision.

DOT National Transportation Integrated Search

2008-08-01

The potential for vessel collisions with bridges is rapidly increasing, as a larger number of heavier vessels are making more frequent trips under bridges. In the United States, rigorous design of bridges for vessel collision was first incorporated i...

Lateral Bracing of Bridge Girders by Permanent Metal Deck Forms

DOT National Transportation Integrated Search

2005-01-10

Lateral torsional buckling is a failure mode that often controls the design of steel bridge girders during construction. Bracing in the form of cross-frames and diaphragms are often provided at locations along the bridge length to reduce the unbraced...

Synthesis and evaluation of the service limit state of engineered fills for bridge support.

DOT National Transportation Integrated Search

2016-02-02

This report synthesizes the current service limit state (SLS) design and analyses of engineered fills for bridge support used as shallow foundations. The SLS for settlement and deformations of bridge supports are summarized. Extensive literature revi...

Reserves in load capacity assessment of existing bridges

NASA Astrophysics Data System (ADS)

Žitný, Jan; Ryjáček, Pavel

2017-09-01

High percentage of all railway bridges in the Czech Republic is made of structural steel. Majority of these bridges is designed according to historical codes and according to the deterioration, they have to be assessed if they satisfy the needs of modern railway traffic. The load capacity assessment of existing bridges according to Eurocodes is however often too conservative and especially, braking and acceleration forces cause huge problems to structural elements of the bridge superstructure. The aim of this paper is to review the different approaches for the determination of braking and acceleration forces. Both, current and historical theoretical models and in-situ measurements are considered. The research of several local European state norms superior to Eurocode for assessment of existing railway bridges shows the big diversity of used local approaches and the conservativeness of Eurocode. This paper should also work as an overview for designers dealing with load capacity assessment, revealing the reserves for existing bridges. Based on these different approaches, theoretical models and data obtained from the measurements, the method for determination of braking and acceleration forces on the basis of real traffic data should be proposed.

Classical and Modern Design Solutions in Conceptual Design of a Pedestrian Bridge over Vistula River in Cracow

NASA Astrophysics Data System (ADS)

Ryż, Karol; Pańtak, Marek

2017-10-01

In the paper the design concept of the steel pedestrian bridge over Vistula river in Cracow, Poland has been characterised. The footbridge was designed as a truss structure with steel pipes, Warren truss configuration, arched bottom chord and spans 15.5+120.0+15.5 m. Intensive tourist traffic around the Wawel Castle in Cracow, directed towards the historic Kazimierz district, Wawel Hill and the Old Town Market Place requires the creation of a bridge structure over the Vistula River that will meet both the communication and recreation functions. An additional aim was to design a structure which architectural form will not unduly and negatively interfere in the environment and will join the technical capabilities of the XXI century with the charm of nearby historic buildings.

A-jacks and Aquawrap installations in Utah : scour revetment performance evaluation, final report, December 2009.

DOT National Transportation Integrated Search

2009-12-01

This is a performance evaluation report for A-Jacks, an articulated concrete block designed to protect bridge elements exposed to the river scouring forces, and for Aquawrap, a glass fiber reinforced polymer designed to protect and strengthen bridge ...

Development of guidelines for incorporation of vertical ground motion effects in seismic design of highway bridges.

DOT National Transportation Integrated Search

2008-05-01

This study was undertaken with the objective of assessing the current provisions in SDC-2006 for incorporating : vertical effects of ground motions in seismic evaluation and design of ordinary highway bridges. A : comprehensive series of simulations ...

Fracture critical analysis procedures and design and retrofit approaches for pony truss bridges in Ohio.

DOT National Transportation Integrated Search

2016-10-01

The study outlined in this report aimed to quantify the available redundancy in pony truss bridge systems : constructed using standard designs and practices in the state of Ohio. A method of conducting refined : three-dimensional nonlinear finite ele...

1. Photocopy of engineering drawing (original in the Office of ...

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

1. Photocopy of engineering drawing (original in the Office of the Cuyahoga County Engineer)--1907 NORTH ROCKY RIVER BRIDGE--PROPOSED DESIGN--REINFORCED CONCRETE: AN ALTERNATIVE DESIGN FOR THE DETROIT AVENUE CROSSING - Rocky River Bridge, Spanning Beaver Dam River, Rocky River, Cuyahoga County, OH

Feasibility evaluation of utilizing high-strength concrete in design and construction of highway bridge structures.

DOT National Transportation Integrated Search

1994-01-01

The objective of this investigation was to evaluate the feasibility of using high-strength concrete in the design and construction of highway bridge structures. A literature search was conducted; a survey of five regional fabrication plants was perfo...

Field demonstration of new bridge approach slab designs and performance : [tech summary].

DOT National Transportation Integrated Search

2014-06-01

The Louisiana Department of Transportation and Development (DOTD) has launched a major e ort to solve : the bridge bump problem by changing the design of approach slabs where di erential settlement is expected. : The objective is to nd a fe...

Post-tensioning and splicing of precast/prestressed bridge beams to extend spans

NASA Astrophysics Data System (ADS)

Collett, Brandon S.; Saliba, Joseph E.

2002-06-01

This paper explores the status and techniques of post-tensioning and splicing precast concrete I-beams in bridge applications. It will look at the current practices that have been used in the United States and comment on the advantages of these techniques. Representative projects are presented to demonstrate the application and success of specific methods used. To demonstrate the benefits of using post-tensioning and splicing to extend spans, multiple analysis of simple span post-tensioned I-beams were performed varying such characteristics as beam spacing, beam sections, beam depth and concrete strength. Tables were then developed to compare the maximum span length of a prestressed I-beam versus a one segment or a spliced three segment post-tensioned I-beam. The lateral stability of the beam during fabrication, transportation and erection is also examined and discussed. These tables are intended to aid designers and owners in preliminary project studies to determine if post-tensioning can be beneficial to their situation. AASHTO Standard Specifications(2) will be used as basic guidelines and specifications. In many cases, post-tensioning was found to extend the maximum span length of a typical 72-inch precast I-beam more than 40 feet over conventional prestress.

Prosthetic reconstruction of dentitions seriously compromised by periodontal disease.

PubMed

Lundgren, D

1991-07-01

Dentitions seriously compromised by periodontal disease are often in need not only of cause-related periodontal therapy of high quality but also of relevant prosthetic rehabilitation. Contrary to traditional claims, clinical investigations published during the last 2 decades demonstrate that, if adequately treated and controlled, such dentitions can carry fixed, cross-arch bridges on an extremely reduced amount of periodontium, with a good long-range prognosis. It has also been shown that a markedly reduced but healthy and favourably distributed periodontium supporting such constructions can withstand occlusal forces of considerable magnitude. Another controversial topic, related to fixed bridges, involves indications and contra-indications for cantilever segments. Some clinical investigations demonstrate a markedly increased risk of failure if the fixed bridge is provided with cantilever units, while other controlled studies with defined specifications on the design of the constructions exhibit a high success rate after 8 years or more also for bridgework where 2 or 3 cantilever units are included. The force pattern along cantilever segments of both tooth-supported and implant-supported bridges has been extensively studied. The results show that the force distribution depends not only on the occlusal contact pattern and the dimensioning of the cantilever beam, but also on the type of prosthetic construction in the opposite jaw occluding with the cantilever segment. The free-standing, implant-supported bridge has recently become an important treatment modality for rehabilitation of the partially edentulous jaw, and follow-up studies demonstrate a high success rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Upper Secondary Chemistry Students in a Pharmacochemistry Research Community

NASA Astrophysics Data System (ADS)

van Rens, Lisette; van Muijlwijk, Jacqueline; Beishuizen, Jos; van der Schee, Joop

2013-04-01

This study deals with the participation of 10 upper secondary chemistry students, aged 16-17, and their chemistry teacher in a pharmacochemistry research community on anti-allergy medicines at VU University, Amsterdam, The Netherlands. Participation of students in scientific research raises the question of how to bridge the gap between an upper secondary school inquiry practice and a scientific research practice. To bridge this gap, a design based on 6 principles derived from an educational model of a community of learners was proposed. The study first aimed at revealing whether the proposed principles were necessary according to the students, their teacher and three pharmacochemistry researchers for successful participation of the students in the research community. Second, the study examined whether the students' understanding of discipline-specific content knowledge, interest in scientific research and knowledge about the nature of science changed during the course of the study. Data were obtained from questionnaires, interviews and video tapes. The results indicated that according to the teacher all 6 principles were necessary to bridge the gap, whereas according to the students 1 principle and according to the pharmacochemistry researchers 2 principles were necessary but difficult to achieve. Furthermore, all students gained discipline-specific content knowledge. Their interest in scientific research exhibited a positive change and their knowledge about the nature of science increased. The implications for further research and practice are discussed.

In Situ Formation of an Azo Bridge on Proteins Controllable by Visible Light.

PubMed

Hoppmann, Christian; Maslennikov, Innokentiy; Choe, Senyon; Wang, Lei

2015-09-09

Optical modulation of proteins provides superior spatiotemporal resolution for understanding biological processes, and photoswitches built on light-sensitive proteins have been significantly advancing neuronal and cellular studies. Small molecule photoswitches could complement protein-based switches by mitigating potential interference and affording high specificity for modulation sites. However, genetic encodability and responsiveness to nonultraviolet light, two desired properties possessed by protein photoswitches, are challenging to be engineered into small molecule photoswitches. Here we developed a small molecule photoswitch that can be genetically installed onto proteins in situ and controlled by visible light. A pentafluoro azobenzene-based photoswitchable click amino acid (F-PSCaa) was designed to isomerize in response to visible light. After genetic incorporation into proteins via the expansion of the genetic code, F-PSCaa reacts with a nearby cysteine within the protein generating an azo bridge in situ. The resultant bridge is switchable by visible light and allows conformation and binding of CaM to be regulated by such light. This photoswitch should prove valuable in optobiology for its minimal interference, site flexibility, genetic encodability, and response to the more biocompatible visible light.

Wearing surface testing : Yukon River bridge.

DOT National Transportation Integrated Search

2012-12-01

The Yukon River Bridge, also known as the E.L. Patton Bridge, carries the twolane Dalton Highway and the trans-Alaska oil pipeline across the Yukon River at a 6% : grade. It is 30 feet wide, with 6 spans; it was designed to withstand -60 degrees Fahr...

Crash test and evaluation of the TxDOT T631 bridge rail.

DOT National Transportation Integrated Search

2014-01-01

In August 2010, Midwest Roadside Safety Facility (MwRSF) developed and crash tested a low-cost, energy-absorbing bridge rail for the Manual for Assessing Safety Hardware (MASH) TL-3 applications. This low-cost bridge rail was designed to be compatibl...

Continuity diaphragm for skewed continuous span precast prestressed concrete girder bridges : technical summary report.

DOT National Transportation Integrated Search

2004-03-01

Most highway bridges are built as cast-in-place : reinforced concrete slabs and prestressed concrete : girders. The shear connectors on the top of the girders : assure composite action between the slabs and : girders. The design guidelines for bridge...

Wireless data collection retrievals of bridge inspection/management information.

DOT National Transportation Integrated Search

2017-02-28

To increase the efficiency and reliability of bridge inspections, MDOT contracted to have a 3D-model-based data entry application for mobile tablets developed to aid inspectors in the field. The 3D Bridge App is a mobile software tool designed to fac...

Design, construction, and field testing of an ultra high performance concrete pi-girder bridge.

DOT National Transportation Integrated Search

2011-01-01

The Jakway Park Bridge in Buchanan County, Iowa is the first bridge constructed with a new prestesssed girder system composed of : precast Ultra-High Performance Concrete (UHPC). These girders employ an integral deck to facilitate construction and ar...

Methods for strengthening reinforced concrete bridge girders containing poorly detailed flexural steel using near-surface mounted metallics.

DOT National Transportation Integrated Search

2015-08-01

Many older reinforced concrete deck girder (RCDG) bridges contain straight-bar terminations of flexural reinforcement in : flexural tension zones without special detailing. Common bridge design practice of the 1950s did not consider the additional : ...

Data collection and evaluation of continuity detail for John James Audubon Bridge No. 61390613004101.

DOT National Transportation Integrated Search

2014-10-01

This report summarizes findings from monitoring data that was collected over a two-year period from Bridge No. : 61390613004101 in the John James Audubon Project, which was formerly designated as Bridge #2 prior to : construction completion. The brid...

Role to Be Played by Independent Geotechnical Supervision in the Foundation for Bridge Construction

NASA Astrophysics Data System (ADS)

Sobala, Dariusz; Rybak, Jarosław

2017-10-01

Some remarks concerning the necessity of employing an independent and over all ethical geotechnical survey were presented in the paper. Starting from the design phase, through the whole construction process, the importance of geotechnical engineer is stated in legal acts. Numerous testing technologies serve for the calibration of geotechnical technologies and allow for confirming the quality and capacity of piles. Special emphasis was payed to the involvement of scientifical and research institutions which can not only serve services but also can postprocess and methodize collected data. Such databases enable for new codes, methods and recommendations. Selection of deep foundations for bridge-type structures is most often dependent on complex geotechnical conditions, concentrated loads and constraints for pier displacements. Besides the last ones, prior to more common introduction of the design-construct system, could be a convenient justification for design engineer, who imposed deep foundation because he did not want or was not able to estimate the effect of pier settlement on civil engineering structure. The paper provides some notes about the need to engage a geotechnical supervising service of high competency and ethical quality during engineering and construction stages of foundations for bridge-type structures where legal requirements are of special consideration. Successive stages of projects are reviewed and research methods used for current calibration of geotechnical technologies and verification of geotechnical work quality are analysed. Special attention is given to potential involvement of independent R&D institutions which, apart from rendering specific services, also collect and systemize the research results thus enabling, in the long term, to revise engineering standards, instructions and guidelines.

Multi-Hazard Assessment of Scour Damaged Bridges with UAS-Based Measurements

NASA Astrophysics Data System (ADS)

Özcan, O.; Ozcan, O.

2017-12-01

Flood and stream induced scour occurring in bridge piers constructed on rivers is one of the mostly observed failure reasons in bridges. Scour induced failure risk in bridges and determination of the alterations in bridge safety under seismic effects has the ultimate importance. Thus, for the determination of bridge safety under the scour effects, the scour amount under bridge piers should be designated realistically and should be tracked and updated continuously. Hereby, the scour induced failures in bridge foundation systems will be prevented and bridge substructure design will be conducted safely. In this study, in order to measure the amount of scour in bridge load bearing system (pile foundations and pile abutments) and to attain very high definition 3 dimensional models of river flood plain for the flood analysis, unmanned aircraft system (UAS) based measurement methods were implemented. UAS based measurement systems provide new and practical approach and bring high precision and reliable solutions considering recent measurement systems. For this purpose, the reinforced concrete (RC) bridge that is located on Antalya Boğaçayı River, Turkey and that failed in 2003 due to flood-induced scour was selected as the case study. The amount of scour occurred in bridge piers and piles was determined realistically and the behavior of bridge piers under scour effects was investigated. Future flood effects and the resultant amount of scour was determined with HEC-RAS software by using digital surface models that were obtained at regular intervals using UAS for the riverbed. In the light of the attained scour measurements and expected scour after a probable flood event, the behavior of scour damaged RC bridge was investigated by pushover and time history analyses under lateral and vertical seismic loadings. In the analyses, the load and displacement capacity of bridge was observed to diminish significantly under expected scour. Thus, the deterioration in multi hazard performance of the bridge was monitored significantly in the light of updated bridge load bearing system capacity. Regarding the case study, UAS based and continuously updated bridge multi hazard risk detection system was established that can be used for bridges located on riverbed.

Subcellular Redox Targeting: Bridging in Vitro and in Vivo Chemical Biology.

PubMed

Long, Marcus J C; Poganik, Jesse R; Ghosh, Souradyuti; Aye, Yimon

2017-03-17

Networks of redox sensor proteins within discrete microdomains regulate the flow of redox signaling. Yet, the inherent reactivity of redox signals complicates the study of specific redox events and pathways by traditional methods. Herein, we review designer chemistries capable of measuring flux and/or mimicking subcellular redox signaling at the cellular and organismal level. Such efforts have begun to decipher the logic underlying organelle-, site-, and target-specific redox signaling in vitro and in vivo. These data highlight chemical biology as a perfect gateway to interrogate how nature choreographs subcellular redox chemistry to drive precision redox biology.

Pressure-Transducer Simulator

NASA Technical Reports Server (NTRS)

Simon, Richard A.

1987-01-01

Simulation circuit operates under remote, automatic, or manual control to produce electrical outputs similar to pressure transducer. Specific circuit designed for simulations of Space Shuttle main engine. General circuit concept adaptable to other simulation and control systems involving several operating modes. Switches and amplifiers respond to external control signals and panel control settings to vary differential excitation of resistive bridge. Output voltage or passive terminal resistance made to equal pressure transducer in any of four operating modes.

Design and evaluation of steel bridges with double composite action

DOT National Transportation Integrated Search

2010-02-01

This report presents findings from a cooperative USF/URS/FDOT research study undertaken to develop design rules for : double composite steel bridges. In the study, a 48 ft long, 16 ft wide, 4 ft. 10 in. deep trapezoidal HPS 70W box section : desig...

Virtual Bridge Design

ERIC Educational Resources Information Center

Bisogno, Janet; JeanPierre, Bobby

2008-01-01

The West Point Bridge Design (WPBD) building project engages students in project-based learning by giving them a real-life problem to solve. By using technology, students are able to become involved in solving problems that they normally would not encounter. Involvement with interactive websites, such as WPBD, assists students in using…

25 CFR Appendix D to Subpart C - Cost To Construct

Code of Federal Regulations, 2012 CFR

2012-04-01

... the Adequate Standard Characteristics (see Table 1). For roadways, the recommended design of the..., Pavement Costs, and Incidental Costs. For bridges, costs are derived from costs in the National Bridge...) with inadequate drainage and alignment that generally follows existing ground 100 4 A designed and...

Venture Creation Programs: Bridging Entrepreneurship Education and Technology Transfer

ERIC Educational Resources Information Center

Lackéus, Martin; Williams Middleton, Karen

2015-01-01

Purpose: The purpose of this paper is to explore how university-based entrepreneurship programs, incorporating real-life venture creation into educational design and delivery, can bridge the gap between entrepreneurship education and technology transfer within the university environment. Design/methodology/approach: Based on a literature review…

Feasibility evaluation of utilizing high strength concrete in design and construction of highway bridge structures : interim report.

DOT National Transportation Integrated Search

1992-12-01

The objective of this investigation was to evaluate the feasibility of using high-strength concrete in the design and construction of highway bridge structures. A literature search was conducted; a survey of five regional fabrication plants was perfo...

Estimation of potential bridge scour at bridges on state routes in South Dakota, 2003-07

USGS Publications Warehouse

Thompson, Ryan F.; Fosness, Ryan L.

2008-01-01

Flowing water can erode (scour) soils and cause structural failure of a bridge by exposing or undermining bridge foundations (abutments and piers). A rapid scour-estimation technique, known as the level-1.5 method and developed by the U.S. Geological Survey, was used to evaluate potential scour at bridges in South Dakota in a study conducted in cooperation with the South Dakota Department of Transportation. This method was used during 2003-07 to estimate scour for the 100-year and 500-year floods at 734 selected bridges managed by the South Dakota Department of Transportation on State routes in South Dakota. Scour depths and other parameters estimated from the level-1.5 analyses are presented in tabular form. Estimates of potential contraction scour at the 734 bridges ranged from 0 to 33.9 feet for the 100-year flood and from 0 to 35.8 feet for the 500-year flood. Abutment scour ranged from 0 to 36.9 feet for the 100-year flood and from 0 to 45.9 feet for the 500-year flood. Pier scour ranged from 0 to 30.8 feet for the 100-year flood and from 0 to 30.7 feet for the 500-year flood. The scour depths estimated by using the level-1.5 method can be used by the South Dakota Department of Transportation and others to identify bridges that may be susceptible to scour. Scour at 19 selected bridges also was estimated by using the level-2 method. Estimates of contraction, abutment, and pier scour calculated by using the level-1.5 and level-2 methods are presented in tabular and graphical formats. Compared to level-2 scour estimates, the level-1.5 method generally overestimated scour as designed, or in a few cases slightly underestimated scour. Results of the level-2 analyses were used to develop regression equations for change in head and average velocity through the bridge opening. These regression equations derived from South Dakota data are compared to similar regression equations derived from Montana and Colorado data. Future level-1.5 scour investigations in South Dakota may benefit from the use of these South Dakota-specific regression equations for estimating change in stream head and average velocity at the bridge.

Biomaterials Made from Coiled-Coil Peptides.

PubMed

Conticello, Vincent; Hughes, Spencer; Modlin, Charles

The development of biomaterials designed for specific applications is an important objective in personalized medicine. While the breadth and prominence of biomaterials have increased exponentially over the past decades, critical challenges remain to be addressed, particularly in the development of biomaterials that exhibit highly specific functions. These functional properties are often encoded within the molecular structure of the component molecules. Proteins, as a consequence of their structural specificity, represent useful substrates for the construction of functional biomaterials through rational design. This chapter provides an in-depth survey of biomaterials constructed from coiled-coils, one of the best-understood protein structural motifs. We discuss the utility of this structurally diverse and functionally tunable class of proteins for the creation of novel biomaterials. This discussion illustrates the progress that has been made in the development of coiled-coil biomaterials by showcasing studies that bridge the gap between the academic science and potential technological impact.

Testing of full-size reinforced concrete beams strengthened with FRP composites : experimental results and design methods verification

DOT National Transportation Integrated Search

2000-06-01

In 1997, a load rating of an historic reinforced concrete bridge in Oregon, Horsetail Creek Bridge, indicated substandard shear and moment capacities of the beams. As a result, the Bridge was strengthened with fiber reinforced : polymer composites as...

Development of degradation rates for various bridge types in the state of Ohio : executive summary report.

DOT National Transportation Integrated Search

2011-03-01

The Ohio Department of Transportation (ODOT) maintains a Bridge Management System (BMS) which is : responsible for collecting and maintaining historical and longitudinal data by year for all the bridges in : Ohio.BMS aids ODOT in tracking, design, pl...

Development of Degradation Rates for Various Bridge Types in the State of Ohio : Executive Summary Report

DOT National Transportation Integrated Search

2011-03-01

The Ohio Department of Transportation (ODOT) maintains a Bridge Management System (BMS) which is responsible for collecting and maintaining historical and longitudinal data by year for all the bridges in Ohio.BMS aids ODOT in tracking, design, planni...

Long-term behavior of integral abutment bridges : appendix E, INDOT design manual : selected recommendations for integral abutment bridges.

DOT National Transportation Integrated Search

2011-01-01

Integral abutment (IA) construction has become the preferred method over conventional construction for use with typical highway bridges. However, the use of these structures is limited due to state mandated length and skew limitations. To expand thei...

History of early bridge specifications : a reprint of a paper by J. N. Clary.

DOT National Transportation Integrated Search

2006-01-01

This report is a reprint of an informed review of the specifications for iron and steel bridges, both railroad and highway structures, dating from the mid-19th through the early 20th centuries. It is reprinted with only minor editing as a companion t...

Development of micro-electromechanical system (MEMS) cochlear biomodel

NASA Astrophysics Data System (ADS)

Ngelayang, Thailis Bounya Anak; Latif, Rhonira

2015-05-01

Human cochlear is undeniably one of the most amazing organs in human body. The functional mechanism is very unique in terms of its ability to convert the sound waves in the form of mechanical vibrations into the electrical nerve impulses. It is known that the normal human auditory system can perceive the audible frequency range between 20 Hz to 20 kHz. Scientists have conducted several researches trying to build the artificial basilar membrane in the human cochlea (cochlear biomodel). Micro-electromechanical system (MEMS) is one of the potential inventions that have the ability to mimic the active behavior of the basilar membrane. In this paper, an array of MEMS bridge beams that are mechanically sensitive to the perceived audible frequency has been proposed. An array of bridge bridge beams with 0.5 µm thickness and length varying from 200 µm to 2000 µm have been designed operate within the audible frequency range. In the bridge beams design, aluminium (Al), copper (Cu), tantalum (Ta) and platinum (Pt) have considered as the material for the bridge beam structure. From the finite element (FE) and lumped element (LE) models of the MEMS bridge beams, platinum has been found to be the best material for the cochlear biomodel design, closely mimicking the basilar membrane.

Development of micro-electromechanical system (MEMS) cochlear biomodel

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

Ngelayang, Thailis Bounya Anak; Latif, Rhonira

Human cochlear is undeniably one of the most amazing organs in human body. The functional mechanism is very unique in terms of its ability to convert the sound waves in the form of mechanical vibrations into the electrical nerve impulses. It is known that the normal human auditory system can perceive the audible frequency range between 20 Hz to 20 kHz. Scientists have conducted several researches trying to build the artificial basilar membrane in the human cochlea (cochlear biomodel). Micro-electromechanical system (MEMS) is one of the potential inventions that have the ability to mimic the active behavior of the basilar membrane. Inmore » this paper, an array of MEMS bridge beams that are mechanically sensitive to the perceived audible frequency has been proposed. An array of bridge bridge beams with 0.5 µm thickness and length varying from 200 µm to 2000 µm have been designed operate within the audible frequency range. In the bridge beams design, aluminium (Al), copper (Cu), tantalum (Ta) and platinum (Pt) have considered as the material for the bridge beam structure. From the finite element (FE) and lumped element (LE) models of the MEMS bridge beams, platinum has been found to be the best material for the cochlear biomodel design, closely mimicking the basilar membrane.« less

SBION: A Program for Analyses of Salt-Bridges from Multiple Structure Files.

PubMed

Gupta, Parth Sarthi Sen; Mondal, Sudipta; Mondal, Buddhadev; Islam, Rifat Nawaz Ul; Banerjee, Shyamashree; Bandyopadhyay, Amal K

2014-01-01

Salt-bridge and network salt-bridge are specific electrostatic interactions that contribute to the overall stability of proteins. In hierarchical protein folding model, these interactions play crucial role in nucleation process. The advent and growth of protein structure database and its availability in public domain made an urgent need for context dependent rapid analysis of salt-bridges. While these analyses on single protein is cumbersome and time-consuming, batch analyses need efficient software for rapid topological scan of a large number of protein for extracting details on (i) fraction of salt-bridge residues (acidic and basic). (ii) Chain specific intra-molecular salt-bridges, (iii) inter-molecular salt-bridges (protein-protein interactions) in all possible binary combinations (iv) network salt-bridges and (v) secondary structure distribution of salt-bridge residues. To the best of our knowledge, such efficient software is not available in public domain. At this juncture, we have developed a program i.e. SBION which can perform all the above mentioned computations for any number of protein with any number of chain at any given distance of ion-pair. It is highly efficient, fast, error-free and user friendly. Finally we would say that our SBION indeed possesses potential for applications in the field of structural and comparative bioinformatics studies. SBION is freely available for non-commercial/academic institutions on formal request to the corresponding author (akbanerjee@biotech.buruniv.ac.in).

23 CFR 650.807 - Bridges requiring a USCG permit.

Code of Federal Regulations, 2013 CFR

2013-04-01

... prescribed in 49 CFR part 7, appendix D. (d) The HA shall accomplish sufficient preliminary design and... alternative shall be included with any proposal for a movable bridge to provide a comparative analysis of..., safety, environmental and navigational needs along with highway costs when designing a proposed navigable...

23 CFR 650.807 - Bridges requiring a USCG permit.

Code of Federal Regulations, 2010 CFR

2010-04-01

... prescribed in 49 CFR part 7, appendix D. (d) The HA shall accomplish sufficient preliminary design and... alternative shall be included with any proposal for a movable bridge to provide a comparative analysis of..., safety, environmental and navigational needs along with highway costs when designing a proposed navigable...

23 CFR 650.807 - Bridges requiring a USCG permit.

Code of Federal Regulations, 2011 CFR

2011-04-01

... prescribed in 49 CFR part 7, appendix D. (d) The HA shall accomplish sufficient preliminary design and... alternative shall be included with any proposal for a movable bridge to provide a comparative analysis of..., safety, environmental and navigational needs along with highway costs when designing a proposed navigable...

23 CFR 650.807 - Bridges requiring a USCG permit.

Code of Federal Regulations, 2014 CFR

2014-04-01

... prescribed in 49 CFR part 7, appendix D. (d) The HA shall accomplish sufficient preliminary design and... alternative shall be included with any proposal for a movable bridge to provide a comparative analysis of..., safety, environmental and navigational needs along with highway costs when designing a proposed navigable...

23 CFR 650.807 - Bridges requiring a USCG permit.

Code of Federal Regulations, 2012 CFR

2012-04-01

... prescribed in 49 CFR part 7, appendix D. (d) The HA shall accomplish sufficient preliminary design and... alternative shall be included with any proposal for a movable bridge to provide a comparative analysis of..., safety, environmental and navigational needs along with highway costs when designing a proposed navigable...

Investigation of flange failures in falsework cap and sill beams : recommendations for the design of beams and posts in bridge falsework.

DOT National Transportation Integrated Search

2008-12-01

Recent field observations in bridge falsework identified potential deficiencies in the design of falsework resulting in : localized bending in sill and cap beam flanges and lateral buckling in other beams. Possible limits states associated with : the...

Skewed steel bridges, part ii : cross-frame and connection design to ensure brace effectiveness : technical summary.

DOT National Transportation Integrated Search

2017-08-01

Skewed bridges in Kansas are often designed such that the cross-frames are carried parallel to the skew angle up to 40, while many other states place cross-frames perpendicular to the girder for skew angles greater than 20. Skewed-parallel cross-...

Skewed steel bridges, part ii : cross-frame and connection design to ensure brace effectiveness : final report.

DOT National Transportation Integrated Search

2017-08-01

Skewed bridges in Kansas are often designed such that the cross-frames are carried parallel to the skew angle up to 40, while many other states place cross-frames perpendicular to the girder for skew angles greater than 20. Skewed-parallel cross-...

MASH TL-3 testing and evaluation of the TXDOT T131RC bridge rail transition.

DOT National Transportation Integrated Search

2013-03-01

This project designed and crash tested a transition design for the Texas Department of Transportation (TxDOT) T131RC Bridge Rail that would meet the strength and safety performance criteria for Test Level 3 of American Association of State Highway Of...

Evaluation of performance and maximum length of continuous decks in bridges : part 1.

DOT National Transportation Integrated Search

2011-06-01

The purpose of this research was to evaluate the performance history of continuous bridge decks in the State of Georgia, to determine why the current design detail works, to recommend a new design detail, and to recommend the maximum and/or optimum l...

From Goal-Oriented Requirements to Event-B Specifications

NASA Technical Reports Server (NTRS)

Aziz, Benjamin; Arenas, Alvaro E.; Bicarregui, Juan; Ponsard, Christophe; Massonet, Philippe

2009-01-01

In goal-oriented requirements engineering methodologies, goals are structured into refinement trees from high-level system-wide goals down to fine-grained requirements assigned to specific software/ hardware/human agents that can realise them. Functional goals assigned to software agents need to be operationalised into specification of services that the agent should provide to realise those requirements. In this paper, we propose an approach for operationalising requirements into specifications expressed in the Event-B formalism. Our approach has the benefit of aiding software designers by bridging the gap between declarative requirements and operational system specifications in a rigorous manner, enabling powerful correctness proofs and allowing further refinements down to the implementation level. Our solution is based on verifying that a consistent Event-B machine exhibits properties corresponding to requirements.

Bridging the Gap: Towards a Cell-Type Specific Understanding of Neural Circuits Underlying Fear Behaviors

PubMed Central

McCullough, KM; Morrison, FG; Ressler, KJ

2016-01-01

Fear and anxiety-related disorders are remarkably common and debilitating, and are often characterized by dysregulated fear responses. Rodent models of fear learning and memory have taken great strides towards elucidating the specific neuronal circuitries underlying the learning of fear responses. The present review addresses recent research utilizing optogenetic approaches to parse circuitries underlying fear behaviors. It also highlights the powerful advances made when optogenetic techniques are utilized in a genetically defined, cell-type specific, manner. The application of next-generation genetic and sequencing approaches in a cell-type specific context will be essential for a mechanistic understanding of the neural circuitry underlying fear behavior and for the rational design of targeted, circuit specific, pharmacologic interventions for the treatment and prevention of fear-related disorders. PMID:27470092

High extinction ratio terahertz wire-grid polarizers with connecting bridges on quartz substrates.

PubMed

Cetnar, John S; Vangala, Shivashankar; Zhang, Weidong; Pfeiffer, Carl; Brown, Elliott R; Guo, Junpeng

2017-03-01

A terahertz (THz) wire-grid polarizer with metallic bridges on a quartz substrate was simulated, fabricated, and tested. The device functions as a wide-band polarizer to incident THz radiation. In addition, the metallic bridges permit the device to function as a transparent electrode when a DC bias is applied to it. Three design variations of the polarizer with bridges and a polarizer without bridges were studied. Results show the devices with bridges have average s-polarization transmittance of less than -3  dB and average extinction ratios of approximately 40 dB across a frequency range of 220-990 GHz and thus are comparable to a polarizer without bridges.

The Importance of Bridging

ERIC Educational Resources Information Center

Zamboni, Camilla

2014-01-01

In this article, I will discuss the importance of the fundamental aspect of "bridging" in the wider context of language teaching. I will use "bridging" particularly in terms of cultural differences and underline the pivotal role of specific techniques, in a language class as well as in a pedagogy class or seminar, to help…

14. Photographic copy of photocopy of bridge drawing, reinforced rod ...

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

14. Photographic copy of photocopy of bridge drawing, reinforced rod specifications (June 12, 1937, original drawing on file in Structures Section, Utah Department of Transportation, Salt Lake City, Utah). SHEET NO. 6 OF 6 SHEETS. - Gould Wash Bridge, Spanning Gould Wash at State Route 9, Hurricane, Washington County, UT

Reverse engineering of mandible and prosthetic framework: Effect of titanium implants in conjunction with titanium milled full arch bridge prostheses on the biomechanics of the mandible.

PubMed

De Santis, Roberto; Gloria, Antonio; Russo, Teresa; D'Amora, Ugo; Varriale, Angelo; Veltri, Mario; Balleri, Piero; Mollica, Francesco; Riccitiello, Francesco; Ambrosio, Luigi

2014-12-18

This study aimed at investigating the effects of titanium implants and different configurations of full-arch prostheses on the biomechanics of edentulous mandibles. Reverse engineered, composite, anisotropic, edentulous mandibles made of a poly(methylmethacrylate) core and a glass fibre reinforced outer shell were rapid prototyped and instrumented with strain gauges. Brånemark implants RP platforms in conjunction with titanium Procera one-piece or two-piece bridges were used to simulate oral rehabilitations. A lateral load through the gonion regions was used to test the biomechanical effects of the rehabilitations. In addition, strains due to misfit of the one-piece titanium bridge were compared to those produced by one-piece cast gold bridges. Milled titanium bridges had a better fit than cast gold bridges. The stress distribution in mandibular bone rehabilitated with a one-piece bridge was more perturbed than that observed with a two-piece bridge. In particular the former induced a stress concentration and stress shielding in the molar and symphysis regions, while for the latter design these stresses were strongly reduced. In conclusion, prosthetic frameworks changed the biomechanics of the mandible as a result of both their design and manufacturing technology. Copyright © 2014 Elsevier Ltd. All rights reserved.

Non-Seismology Seismology: Using QuakeCatchers to Analyze the Frequency of Bridge Vibrations

NASA Astrophysics Data System (ADS)

Courtier, A. M.; Constantin, C.; Wilson, C. F.

2013-12-01

We conducted an experiment to test the feasibility of measuring seismic waves generated by traffic near James Madison University. We used QuakeCatcher seismometers (originally designed for passive seismic measurement) to measure vibrations associated with traffic on a wooden bridge as well as a nearby concrete bridge. This experiment was a signal processing exercise for a student research project and did not draw any conclusions regarding bridge safety or security. The experiment consisted of two temporary measurement stations comprised of a laptop computer and a QuakeCatcher - a small seismometer that plugs directly into the laptop via a USB cable. The QuakeCatcher was taped to the ground at the edge of the bridge to achieve good coupling, and vibrational events were triggered repeatedly with a control vehicle to accumulate a consistent dataset of the bridge response. For the wooden bridge, the resulting 'seismograms' were converted to Seismic Analysis Code (SAC) format and analyzed in MATLAB. The concrete bridge did not generate vibrations significant enough to trigger the recording mechanism on the QuakeCatchers. We will present an overview of the experimental design and frequency content of the traffic patterns, as well as a discussion of the instructional benefits of using the QuakeCatcher sensors in this non-traditional setting.

Design and Evaluation of Scour for Bridges Using HEC-18 (Volume 3 of 3).

DOT National Transportation Integrated Search

2017-07-04

The overall objective of this research is the development of a new approach for evaluating bridge scour for New Jersey's bridges on non-tidal waterways. The study commenced with a web-based survey of scour practice within the U.S. and a literature re...

Design and Evaluation of Scour for Bridges Using HEC-18 (Volume 1 of 3).

DOT National Transportation Integrated Search

2017-07-04

The overall objective of this research is the development of a new approach for evaluating bridge scour for New Jersey's bridges on non-tidal waterways. The study commenced with a web-based survey of scour practice within the U.S. and a literature re...

Structural load testing and flexure analysis of the Route 701 Bridge in Louisa County, Virginia : supplemental report.

DOT National Transportation Integrated Search

2006-01-01

A continuous slab bridge in Louisa County, Virginia, on Route 701 developed a planar horizontal crack along the length of all three spans. This project was designed to determine if the current 12-ton posted load restriction of the bridge (instituted ...

Coaxial cable sensors and sensing instrument for crack detection in bridge structures--phase I : field qualification/validation planning.

DOT National Transportation Integrated Search

2009-11-01

The objectives of this study are to pre-test analyze a decommissioned reinforced concrete (RC) bridge that is selected in consultation with the New York State Department of Transportation (NYSDOT), and design and plan the field tests of the bridge fo...

Field demonstration of new bridge approach slab designs and performance : [research project capsule].

DOT National Transportation Integrated Search

2008-10-01

A normal bridge approach slab in Louisiana is a reinforced concrete slab. It connects : the bridge deck to the adjacent paved roadway. Its intended functions are: : 1. To span the void that may develop below the slab due to soil erosion or : embankme...

25 CFR 170.507 - Who reviews bridge inspection reports?

Code of Federal Regulations, 2010 CFR

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false Who reviews bridge inspection reports? 170.507 Section 170.507 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Planning, Design, and Construction of Indian Reservation Roads Program Facilities Bridge...

Pennsylvania hardwood timber bridges : field performance after 10 years

Treesearch

James P. Wacker; Carlito Calil

2004-01-01

Several hardwood demonstration timber bridges were built by the Pennsylvania Department of Transportation in the early nineteen nineties. These bridge superstructures are of the recently developed stress-laminated deck design-type using Red Oak lumber laminations that were pressure-treated with creosote preservatives. This paper will describe the data acquisition...

Flexural strength and fatigue of steel fiber reinforced concrete (SFRC) (2004 Hale Boggs Deck) : technical summary report.

DOT National Transportation Integrated Search

2009-12-01

The Luling Bridge (Hale Boggs Memorial Bridge) traverses the Mississippi River in St. Charles : Parish, Louisiana. It was one of the first cable-stayed bridges in the United States and opened to : traffic in 1983. Unique to its design are relatively ...

Design and Evaluation of Scour for Bridges Using HEC-18 (Volume 2 of 3).

DOT National Transportation Integrated Search

2017-07-04

The overall objective of this research is the development of a new approach for evaluating bridge scour for New Jersey's bridges on non-tidal waterways. The study commenced with a web-based survey of scour practice within the U.S. and a literature re...

Structural load testing and flexure analysis of the Route 701 Bridge in Louisa County, Virginia.

DOT National Transportation Integrated Search

2004-01-01

A continuous slab bridge in Louisa County, Virginia, on Route 701 developed a planar horizontal crack along the length of all three spans. This project was designed to determine if the current load rating of the bridge could be raised and to document...

Dynamic loads during failure risk assessment of bridge crane structures

NASA Astrophysics Data System (ADS)

Gorynin, A. D.; Antsev, V. Yu; Shaforost, A. N.

2018-03-01

The paper presents the method of failure risk assessment associated with a bridge crane metal structure at the design stage. It also justifies the necessity of taking into account dynamic loads with regard to the operational cycle of a bridge crane during failure risk assessment of its metal structure.

Testing of full-size reinforced concrete beams strengthened with FRP composites : experimental results and design methods verification(appendices)

DOT National Transportation Integrated Search

2000-06-01

In 1997, a load rating of an historic reinforced concrete bridge in Oregon, Horsetail Creek Bridge, indicated substandard shear and moment capacities of the beams. As a result, the Bridge was strengthened with fiber reinforced polymer composites as a...

Developmental Summer Bridge Programs. What Works Clearinghouse™ Intervention Report

ERIC Educational Resources Information Center

What Works Clearinghouse, 2015

2015-01-01

Developmental summer bridge programs are designed to reduce the need for developmental education in college by providing students with accelerated instruction in areas where additional knowledge and skills are needed to help them succeed in higher education. The WWC identified one study of developmental summer bridge programs that meets WWC…

Summer Bridge Programs. What Works Clearinghouse Intervention Report

ERIC Educational Resources Information Center

What Works Clearinghouse, 2016

2016-01-01

"Summer bridge programs" are designed to ease the transition to college and support postsecondary success by providing students with the academic skills and social resources needed to succeed in a college environment. These programs occur in the summer "bridge" period between high school and college. Although the content of…

Effects of seismic devices on transverse responses of piers in the Sutong Bridge

NASA Astrophysics Data System (ADS)

Shen, Xing; Camara, Alfredo; Ye, Aijun

2015-12-01

The Sutong Bridge in China opened to traffic in 2008, and is an arterial connection between the cities of Nantong and Suzhou. It is a cable-stayed bridge with a main span of 1,088 m. Due to a tight construction schedule and lack of suitable seismic devices at the time, fixed supports were installed between the piers and the girder in the transverse direction. As a result, significant transverse seismic forces could occur in the piers and foundations, especially during a return period of a 2500-year earthquake. Therefore, the piers, foundations and fixed bearings had to be designed extraordinarily strong. However, when larger earthquakes occur, the bearings, piers and foundations are still vulnerable. The recent rapid developments in seismic technology and the performance-based design approach offer a better opportunity to optimize the transverse seismic design for the Sutong Bridge piers. The optimized design can be applied to the Sutong Bridge (as a retrofit), as well as other bridges. Seismic design alternatives utilizing viscous fluid dampers (VFD), or friction pendulum sliding bearings (FPSB), or transverse yielding metallic dampers (TYMD) are thoroughly studied in this work, and the results are compared with those from the current condition with fixed transverse supports and a hypothetical condition in which only sliding bearings are provided on top of the piers (the girder can move "freely" in the transverse direction during the earthquake, except for frictional forces of the sliding bearings). Parametric analyses were performed to optimize the design of these proposed seismic devices. From the comparison of the peak bridge responses in these configurations, it was found that both VFD and TYMD are very effective in the reduction of transverse seismic forces in piers, while at the same time keeping the relative transverse displacements between piers and the box girder within acceptable limits. However, compared to VFD, TYMD do not interact with the longitudinal displacements of the girder, and have simpler details and lower initial and maintenance costs. Although the use of FPSB can also reduce seismic forces, it generally causes the transverse relative displacements to be higher than acceptable limits.

Smart Rocks for Bridge Scour Monitoring: Design and Localization Using Electromagnetic Techniques and Embedded Orientation Sensors

NASA Astrophysics Data System (ADS)

Radchenko, Andro

River bridge scour is an erosion process in which flowing water removes sediment materials (such as sand, rocks) from a bridge foundation, river beds and banks. As a result, the level of the river bed near a bridge pier is lowering such that the bridge foundation stability can be compromised, and the bridge can collapse. The scour is a dynamic process, which can accelerate rapidly during a flood event. Thus, regular monitoring of the scour progress is necessary to be performed at most river bridges. Present techniques are usually expensive, require large man/hour efforts, and often lack the real-time monitoring capabilities. In this dissertation a new method--'Smart Rocks Network for bridge scour monitoring' is introduced. The method is based on distributed wireless sensors embedded in ground underwater nearby the bridge pillars. The sensor nodes are unconstrained in movement, are equipped with years-lasting batteries and intelligent custom designed electronics, which minimizes power consumption during operation and communication. The electronic part consists of a microcontroller, communication interfaces, orientation and environment sensors (such as are accelerometer, magnetometer, temperature and pressure sensors), supporting power supplies and circuitries. Embedded in the soil nearby a bridge pillar the Smart Rocks can move/drift together with the sediments, and act as the free agent probes transmitting the unique signature signals to the base-station monitors. Individual movement of a Smart Rock can be remotely detected processing the orientation sensors reading. This can give an indication of the on-going scour progress, and set a flag for the on-site inspection. The map of the deployed Smart Rocks Network can be obtained utilizing the custom developed in-network communication protocol with signals intensity (RSSI) analysis. Particle Swarm Optimization (PSO) is applied for map reconstruction. Analysis of the map can provide detailed insight into the scour progress and topology. Smart Rocks Network wireless communication is based on the magnetoinductive (MI) link, at low (125 KHz) frequency, allowing for signal to penetrate through the water, rocks, and the bridge structure. The dissertation describes the Smart Rocks Network implementation, its electronic design and the electromagnetic/computational intelligence techniques used for the network mapping.

Building Better Bridges into STEM: A Synthesis of 25 Years of Literature on STEM Summer Bridge Programs

PubMed Central

Ashley, Michael; Cooper, Katelyn M.; Cala, Jacqueline M.; Brownell, Sara E.

2017-01-01

Summer bridge programs are designed to help transition students into the college learning environment. Increasingly, bridge programs are being developed in science, technology, engineering, and mathematics (STEM) disciplines because of the rigorous content and lower student persistence in college STEM compared with other disciplines. However, to our knowledge, a comprehensive review of STEM summer bridge programs does not exist. To provide a resource for bridge program developers, we conducted a systematic review of the literature on STEM summer bridge programs. We identified 46 published reports on 30 unique STEM bridge programs that have been published over the past 25 years. In this review, we report the goals of each bridge program and whether the program was successful in meeting these goals. We identify 14 distinct bridge program goals that can be organized into three categories: academic success goals, psychosocial goals, and department-level goals. Building on the findings of published bridge reports, we present a set of recommendations for STEM bridge programs in hopes of developing better bridges into college. PMID:29146667

The effects of load history and design variables on performance limit states of circular bridge columns - volume 2 : experimental observations.

DOT National Transportation Integrated Search

2015-01-01

This report is the second of three volumes and presents detailed data and test summaries of the experimental portion of the work. In total : 30 large scale reinforced concrete bridge columns are reported in this volume. Recommendations for design and...

Testing of New Bridge Rail and Transition Designs Vol. XIII Appendix L 32-in (813-mm) Thrie-Beam Transition

DOT National Transportation Integrated Search

1997-06-01

This report presents the results of a State Planning and Research (SP&R) pooled-fund study to develop safer bridge rail and transition designsThis pooled-fund study was sponsored by the Federal Highway Administration, 23 States, and the District of C...

Learning Axes and Bridging Tools in a Technology-Based Design for Statistics

ERIC Educational Resources Information Center

Abrahamson, Dor; Wilensky, Uri

2007-01-01

We introduce a design-based research framework, "learning axes and bridging tools," and demonstrate its application in the preparation and study of an implementation of a middle-school experimental computer-based unit on probability and statistics, "ProbLab" (Probability Laboratory, Abrahamson and Wilensky 2002 [Abrahamson, D., & Wilensky, U.…

Bridge-in-a-Backpack(TM) task 3.1: investigating soil - structure interaction - experimental design.

DOT National Transportation Integrated Search

2015-07-01

This report includes fulfillment of Task 3.1 of a multi-task contract to further enhance concrete filled FRP tubes, or : the Bridge in a Backpack. Task 3 is an investigation of soil-structure interaction for the FRP tubes. Task 3.1 is the : design of...

49 CFR 38.83 - Mobility aid accessibility.

Code of Federal Regulations, 2010 CFR

2010-10-01

... shall provide a level-change mechanism or boarding device (e.g., lift, ramp or bridge plate) complying... required. (2) Exception. If lifts, ramps or bridge plates meeting the requirements of this section are... accommodated on a single vehicle. (b) Vehicle lift—(1) Design load. The design load of the lift shall be at...

49 CFR 38.83 - Mobility aid accessibility.

Code of Federal Regulations, 2011 CFR

2011-10-01

... shall provide a level-change mechanism or boarding device (e.g., lift, ramp or bridge plate) complying... required. (2) Exception. If lifts, ramps or bridge plates meeting the requirements of this section are... accommodated on a single vehicle. (b) Vehicle lift—(1) Design load. The design load of the lift shall be at...

33 CFR 117.899 - Youngs Bay and Lewis and Clark River.

Code of Federal Regulations, 2014 CFR

2014-07-01

... SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Oregon § 117.899 Youngs Bay and... blast. (b) The draw of the Oregon State (Old Youngs Bay) highway bridge, mile 2.4, across Youngs Bay... of the Oregon State (Lewis and Clark River) highway bridge, mile 1.0, across the Lewis and Clark...

33 CFR 117.899 - Youngs Bay and Lewis and Clark River.

Code of Federal Regulations, 2012 CFR

2012-07-01

... SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Oregon § 117.899 Youngs Bay and... blast. (b) The draw of the Oregon State (Old Youngs Bay) highway bridge, mile 2.4, across Youngs Bay... of the Oregon State (Lewis and Clark River) highway bridge, mile 1.0, across the Lewis and Clark...

33 CFR 117.899 - Youngs Bay and Lewis and Clark River.

Code of Federal Regulations, 2013 CFR

2013-07-01

... SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Oregon § 117.899 Youngs Bay and... blast. (b) The draw of the Oregon State (Old Youngs Bay) highway bridge, mile 2.4, across Youngs Bay... of the Oregon State (Lewis and Clark River) highway bridge, mile 1.0, across the Lewis and Clark...

Integrating Gender and Group Differences into Bridging Strategy

ERIC Educational Resources Information Center

Yilmaz, Serkan; Eryilmaz, Ali

2010-01-01

The main goal of this study was to integrate gender and group effect into bridging strategy in order to assess the effect of bridging analogy-based instruction on sophomore students' misconceptions in Newton's Third Law. Specifically, the authors developed and benefited from anchoring analogy diagnostic test to merge the effect of group and gender…

33 CFR 117.139 - White River.

Code of Federal Regulations, 2010 CFR

2010-07-01

... OPERATION REGULATIONS Specific Requirements Arkansas § 117.139 White River. (a) The draws of the St. Louis Southwestern railroad bridge, mile 98.9 at Clarendon, the US70 highway bridge, mile 121.7 at DeValls Bluff, the Chicago, Rock Island and Pacific Railroad bridge, mile 122.0 at DeValls Bluff, the Missouri Pacific...

Free energy of solvated salt bridges: a simulation and experimental study.

PubMed

White, Andrew D; Keefe, Andrew J; Ella-Menye, Jean-Rene; Nowinski, Ann K; Shao, Qing; Pfaendtner, Jim; Jiang, Shaoyi

2013-06-20

Charged amino acids are the most common on surfaces of proteins and understanding the interactions between these charged amino acids, salt bridging, is crucial for understanding protein-protein interactions. Previous simulations have been limited to implicit solvent or fixed binding geometry due to the sampling required for converged free energies. Using well-tempered metadynamics, we have calculated salt bridge free energy surfaces in water and confirmed the results with NMR experiments. The simulations give binding free energies, quantitative ranking of salt bridging strength, and insights into the hydration of the salt bridges. The arginine-aspartate salt bridge was found to be the weakest and arginine-glutamate the strongest, showing that arginine can discriminate between aspartate and glutamate, whereas the salt bridges with lysine are indistinguishable in their free energy. The salt bridging hydration is found to be complementary to salt bridge orientation with arginine having specific orientations.

Design, construction and load testing of the Pat Daly Bridge in Washington County, MO, with internal glass fiber reinforced polymers reinforcement.

DOT National Transportation Integrated Search

2013-01-01

The overarching goal of this project is to deploy and assess an innovative corrosion-free bridge construction technology for long-term : performance of new and existing bridges. The research objective of this project is to conduct a comprehensive stu...

77 FR 69576 - Drawbridge Operation Regulation; Thea Foss Waterway Previously Known as City Waterway, Tacoma, WA

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-20

... notification for bridge openings during designated hours. This proposed rule will also remove existing... proposed change will update contact information for requesting emergency bridge openings. DATES: Comments... notice for an opening and allows the bridge to not open during morning and afternoon rush hours. This...

MASH TL-3 crash testing and evaluation of the TxDOT T631 Bridge Rail.

DOT National Transportation Integrated Search

2016-07-01

The Texas Type T631 bridge rail was developed as a low-cost, flexible bridge rail system for TL-2 : applications. Many of the features used for the system tested at MwRSF for TL-3 were incorporated into the : design developed for this project for MAS...

Guidelines to restoring structural integrity of covered bridge members

Treesearch

Ronald W. Anthony

2018-01-01

These guidelines are designed for decision makers (selectmen, county commissioners, city planners, preservation officers, etc.) that have responsibility for repairing and maintaining existing covered bridges to help them understand what goes into making effective decisions about how, and when, to repair a covered bridge. The purpose of these guidelines is to present...

Collision loads on bridge piers : phase 2, report of guidelines for designing bridge piers and abutments for vehicle collisions

DOT National Transportation Integrated Search

2011-03-01

An instrumented, simulated bridge pier was constructed, and two full-scale collisions with an : 80,000-lb van-type tractor-trailer were performed on it. The trailer was ballasted with bags of sand on : pallets. The simulated pier was 36 inches in dia...

Development of wave and surge atlas for the design and protection of coastal bridges in south Louisiana : [tech summary].

DOT National Transportation Integrated Search

2015-02-01

The failures of highway bridges on the Gulf Coast seen in the aftermath of Hurricane Katrina in 2005 were unprecedented. : In the past four decades, wind waves accompanied by high surges from hurricanes have damaged a number of coastal : bridges alon...

Implementation project : strengthening a continuous steel girder bridge in Lakeport, Texas with post-installed shear connectors : Phase 1 : bridge strengthening design and load testing.

DOT National Transportation Integrated Search

2017-03-01

In Implementation Project 5-6719, a non-composite continuous steel girder bridge located in Lakeport, Texas will be strengthened using techniques developed in TxDOT Research Project 0-6719. This strengthening technique involves the use of post-instal...

Design, construction and load testing of the Pat Daly road bridge in Washington County, MO, with internal glass fiber reinforced polymers reinforcement.

DOT National Transportation Integrated Search

2013-01-01

The overarching goal of this project is to deploy and assess an innovative corrosion-free bridge construction technology for long-term : performance of new and existing bridges. The research objective of this project is to conduct a comprehensive stu...

Cross-infrastructure learnings for alternative bridge system designs : a case study on the hybrid composite bridge system.

DOT National Transportation Integrated Search

2015-04-30

The hybrid composite beam (HCB) technology has been presented as a system for short and medium span beam bridges as an alternative to traditional materials such as concrete and steel. A HCB consists of a concrete tied arch encased in a fiber-reinforc...

Coaxial cable sensors and sensing instrument for crack detection in bridge structures--phase I : field qualification/validation planning : final report.

DOT National Transportation Integrated Search

2009-11-06

The objectives of this study are to pre-test analyze a decommissioned RC bridge that is selected in consultation : with New York State Department of Transportation (NYSDOT), and design and plan the field tests of the bridge : for the performance qual...

A distributed cloud-based cyberinfrastructure framework for integrated bridge monitoring

NASA Astrophysics Data System (ADS)

Jeong, Seongwoon; Hou, Rui; Lynch, Jerome P.; Sohn, Hoon; Law, Kincho H.

2017-04-01

This paper describes a cloud-based cyberinfrastructure framework for the management of the diverse data involved in bridge monitoring. Bridge monitoring involves various hardware systems, software tools and laborious activities that include, for examples, a structural health monitoring (SHM), sensor network, engineering analysis programs and visual inspection. Very often, these monitoring systems, tools and activities are not coordinated, and the collected information are not shared. A well-designed integrated data management framework can support the effective use of the data and, thereby, enhance bridge management and maintenance operations. The cloud-based cyberinfrastructure framework presented herein is designed to manage not only sensor measurement data acquired from the SHM system, but also other relevant information, such as bridge engineering model and traffic videos, in an integrated manner. For the scalability and flexibility, cloud computing services and distributed database systems are employed. The information stored can be accessed through standard web interfaces. For demonstration, the cyberinfrastructure system is implemented for the monitoring of the bridges located along the I-275 Corridor in the state of Michigan.

Dynamic response for structural health monitoring of the Penang (I) cable-stayed bridge

NASA Astrophysics Data System (ADS)

Mohammed, M. I.; Sulaeman, E.; Mustapha, F.

2017-03-01

The paper discusses the dynamic response of the Penang (I) cable stayed bridge structure under various moving load representing typical traffic load of the bridge. The bridge has a total span of 440 m excluding the transition bridge that assumed to be not connected structurally to the main bridge structure. The bridge that links the fast growing Pinang Island and the Malaysian Mainland Peninsula has been known to be fully utilized which leads to the construction of Penang (II) bridge and now the third one. Due to highly traffic use of the bridge that may lead to reduction of the bridge design life, the dynamic response of the bridge becomes important to predict critical part of the bridge structure elements including the main girder and the 144 stay cables. The present study reveals that, due to flexible nature of the cable stayed bridge, the moving load that interacts with the natural dynamic characteristics of the bridge, gives significant stress increment compare to proportional static load especially when the moving load is un-symmetric. For this reason, several classes of typical vehicle passing the bridge with various vehicle speeds are investigated to demonstrate their effect on the bridge displacement, internal forces and stresses. The results can be used for further fatigue assessment of the bridge.

Rapid-estimation method for assessing scour at highway bridges

USGS Publications Warehouse

Holnbeck, Stephen R.

1998-01-01

A method was developed by the U.S. Geological Survey for rapid estimation of scour at highway bridges using limited site data and analytical procedures to estimate pier, abutment, and contraction scour depths. The basis for the method was a procedure recommended by the Federal Highway Administration for conducting detailed scour investigations, commonly referred to as the Level 2 method. Using pier, abutment, and contraction scour results obtained from Level 2 investigations at 122 sites in 10 States, envelope curves and graphical relations were developed that enable determination of scour-depth estimates at most bridge sites in a matter of a few hours. Rather than using complex hydraulic variables, surrogate variables more easily obtained in the field were related to calculated scour-depth data from Level 2 studies. The method was tested by having several experienced individuals apply the method in the field, and results were compared among the individuals and with previous detailed analyses performed for the sites. Results indicated that the variability in predicted scour depth among individuals applying the method generally was within an acceptable range, and that conservatively greater scour depths generally were obtained by the rapid-estimation method compared to the Level 2 method. The rapid-estimation method is considered most applicable for conducting limited-detail scour assessments and as a screening tool to determine those bridge sites that may require more detailed analysis. The method is designed to be applied only by a qualified professional possessing knowledge and experience in the fields of bridge scour, hydraulics, and flood hydrology, and having specific expertise with the Level 2 method.

Regulation of the Dynamic Live Load Factor for Calculation of Bridge Structures on High-Speed Railway Mainlines

NASA Astrophysics Data System (ADS)

Dyachenko, Leonid K.; Benin, Andrey V.

2017-06-01

When the high-speed railway traffic is being organized, it becomes necessary to elaborate bridge design standards for high-speed railways (HSR). Methodology of studying the issues of HSR bridge design is based on the comprehensive analysis of domestic research as well as international experience in design, construction and operation of high-speed railways. Serious requirements are imposed on the HSR artificial structures, which raise a number of scientific tasks associated mainly with the issues of the dynamic interaction of the rolling stock and the bridge elements. To ensure safety of traffic and reliability of bridges during the whole period of operation one needs to resolve the dynamic problems of various types of high-speed trains moving along the structures. The article analyses dependences of the magnitude of inertial response on the external stress parameters and proposes a simplified method of determination of the dynamic live load factor caused by the passage of high-speed trains. The usefulness of the given research arises from the reduction of complexity of the complicated dynamic calculations needed to describe a high-speed train travelling along the artificial structures.

Engineering nutritious proteins: improvement of stability in the designer protein MB-1 via introduction of disulfide bridges.

PubMed

Doucet, Alain; Williams, Martin; Gagnon, Mylene C; Sasseville, Maxime; Beauregard, Marc

2002-01-02

Protein design is currently used for the creation of new proteins with desirable traits. In this laboratory the focus has been on the synthesis of proteins with high essential amino acid content having potential applications in animal nutrition. One of the limitations faced in this endeavor is achieving stable proteins despite a highly biased amino acid content. Reported here are the synthesis and characterization of two disulfide-bridged mutants derived from the MB-1 designer protein. Both mutants outperformed their parent protein MB-1 with their bridge formed, as shown by circular dichroism, size exclusion chromatography, thermal denaturation, and proteolytic degradation experiments. When the disulfide bridges were cleaved, the mutants' behavior changed: the mutants significantly unfolded, suggesting that the introduction of Cys residues was deleterious to MB-1-folding. In an attempt to compensate for the mutations used, a Tyr62-Trp mutation was performed, leading to an increase in bulk and hydrophobicity in the core. The Trp-containing disulfide-bridged mutants did not behave as well as the original MB-1Trp, suggesting that position 62 might not be adequate for a compensatory mutation.

Study on the Old Girders in the Widening Hollow Slab Girder Bridge

NASA Astrophysics Data System (ADS)

Wang, Ying; Zhang, Li Fang; Ma, Hai Yan

2018-06-01

Taking the bridge widening project of Shanghai-Hangzhou-Ningbo expressway widening construction project (China) as the background in this paper, the variation law of the internal force of the old bridge in the widening hollow slab girder bridge under vehicle load is studied, which is under the condition of different span lengths and different widening widths. Three different span lengths of the pre-tensioned prestressed hollow slab girder bridges are selected, the spatial finite element models of both the old bridge and the whole structure of widening bridge are established and calculated respectively by Midas/Civil software. The influences of widening and load increasing on the old bridges under the vehicle load are compared and analyzed. In addition, the authors also analyze the influences of different widening widths on the force state of old bridges under the condition of widening the same number of lane. Moreover , the effects on the old bridges that are caused by the uneven foundation settlement of widening bridge structure are also studied in this paper. This paper can provide some references for widening design of hollow slab bridges.

Investigation of Aerodynamic Interference between Twin Deck Bridges

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

Sitek, M. A.; Bojanowski, C.; Lottes, S. A.

2016-05-01

Construction of a twin bridge can be a cost effective and minimally disruptive way to increase capacity when an existing bridge is not near the end of its service life. With ever growing vehicular traffic, when demand approaches the capacity of many existing roads and bridges. Remodeling a structure with an insufficient number of lanes can be a good solution in case of smaller and less busy bridges. Closing down or reducing traffic on crossings of greater importance for the construction period, however, can result in major delays and revenue loss for commerce and transportation as well as increasing themore » traffic load on alternate route bridges. Multiple-deck bridges may be the answer to this issue. A parallel deck can be built next to the existing one, without reducing the flow. Additionally, a new bridge can be designed as a twin or multi-deck structure. Several such structures have been built throughout the United States, among them: - The New NY Bridge Project - the Tappan Zee Hudson River Crossing, - SR-182 Columbia River Bridge, - The Thaddeus Kosciusko Bridge (I-87), - The Allegheny River Bridge, Pennsylvania, which carries I76, - Fred Hartman Bridge, TX, see Figure 1.2. With a growing number of double deck bridges, additional, more detailed, studies on the interaction of such bridge pairs in windy conditions appears appropriate. Aerodynamic interference effects should be examined to assure the aerodynamic stability of both bridges. There are many studies on aerodynamic response of single deck bridges, but the literature on double-deck structures is not extensive. The experimental results from wind tunnels are still limited in number, as a parametric study is required, they can be very time consuming. Literature review shows that some investigation of the effects of gap-width and angle of wind incidence has been done. Most of the CFD computational studies that have been done were limited to 2D simulations. Therefore, it is desirable to investigate twin decks of various cross-sections, gap-to-width ratios, wind speed and direction using three-dimensional CFD simulations. After verification with wind tunnel test results, this type of analysis could become a powerful tool for future designs as well as for monitoring of existing bridges.« less

A statistical model of operational impacts on the framework of the bridge crane

NASA Astrophysics Data System (ADS)

Antsev, V. Yu; Tolokonnikov, A. S.; Gorynin, A. D.; Reutov, A. A.

2017-02-01

The technical regulations of the Customs Union demands implementation of the risk analysis of the bridge cranes operation at their design stage. The statistical model has been developed for performance of random calculations of risks, allowing us to model possible operational influences on the bridge crane metal structure in their various combination. The statistical model is practically actualized in the software product automated calculation of risks of failure occurrence of bridge cranes.

Norbornene-constrained cyclic peptides with hairpin architecture: design, synthesis, conformation, and membrane ion transport.

PubMed

Ranganathan, D; Haridas, V; Kurur, S; Nagaraj, R; Bikshapathy, E; Kunwar, A C; Sarma, A V; Vairamani, M

2000-01-28

A novel family of hairpin cyclic peptides has been designed on the basis of the use of norbornene units as the bridging ligands. The design is flexible with respect to the choice of an amino acid, the ring size, and the nature of the second bridging ligand as illustrated here with the preparation of a large number of norborneno cyclic peptides containing a variety of amino acids in ring sizes varying from 12- to 29-membered, with the choice of the second bridging ligand being a rigid norbornene (11, 13a,b), an adamantane unit (7a,b and 8), or a flexible cystine residue (4a,b and 10). The presence of built-in handles (as protected COOH groups) permits the attachment of a variety of subunits as shown here with the ligation of Leu-Leu, Val-Val, or Aib-Aib pendants in 4b, 7b, and 13b, respectively. This novel class of constrained cyclic peptides are demonstrated to adopt beta-sheet- or hairpin-like conformation as shown by (1)H NMR and CD spectra. Membrane ion-transport studies have shown that the norborneno cyclic peptides 4b and 7b containing Leu-Leu or Val-Val pendants symmetrically placed on the exterior of the ring show high efficiency and selectivity in the transport of specifically monovalent cations. This property can be attributed to the hairpin-like architecture induced by the norbornene unit since the bis-adamantano peptide 15 containing two pairs of Leu-Leu pendants on the exterior is able to transport both monovalent (Na(+), K(+)) and divalent (Mg(2+)/Ca(2+)) cations.

Research and development of weathering resistant bridge steel of Shougang

NASA Astrophysics Data System (ADS)

Yang, Yongda; Wang, Yanfeng; Huang, Leqing; Di, Guobiao; Ma, Changwen; Ma, Qingshen

2017-09-01

To introduce the composition design and mechanical properties and microstructure of the weathering bridge steel which would be used for bridge of Guanting reservoir. We adopt cyclic immersion corrosion test to study corrosion resistance difference of weathering bridge steel and common bridge steel. At the same corrosion time, the weight loss and corrosion rate of weathering bridge steel are lower than the common bridge steel's. Testing phase composition of rust layer by X-ray diffraction, two kinds of test steel's rust layer is mainly composed of Goethite and Fe3O4 and Fe2O3. At the same corrosion time, the percentage composition of goethite in rust layer of weathering bridge steel are significantly higher than common bridge steel's, the higher goethite content is, the compacter rust layer structure is. The compact rust layer would prevent the water and air passing the rust layer, and then preventing the further corrosion reaction, improving the corrosion resistance performance of weathering bridge steel.

Seismic Retrofitting of an Existing Steel Railway Bridge by Fluid Viscous Dampers

NASA Astrophysics Data System (ADS)

Gangopadhyay, Avijit; Ghosh, Aparna Dey

2016-09-01

There are over a lakh of bridges in the Indian Railways, many of which have become seismically deficient, either through aging or due to inadequate seismic design considerations. The extensive damage of bridges all over the world in recent earthquakes has propelled significant advancement in earthquake protection and retrofitting of bridges. Amongst various passive control systems that are reliable as well as cost-effective, Fluid Viscous Dampers (FVDs) are proving to be successful in bridge vibration control. Orificed FVDs, commercially available as Taylor Devices, have already been successfully installed in several bridges worldwide. However, there has been no such application or study related to Indian railway bridges. In this paper, an existing thirty years' old railway bridge in Jharkhand, India, has been analyzed in SAP2000v14 considering reduced stiffness and found deficient when subjected to spectrum-compatible accelerograms. Subsequent retrofitting of the bridge superstructure with FVDs has been carried out and the results indicate substantial reductions in the responses of the bridge deck.

Diderot: a Domain-Specific Language for Portable Parallel Scientific Visualization and Image Analysis.

PubMed

Kindlmann, Gordon; Chiw, Charisee; Seltzer, Nicholas; Samuels, Lamont; Reppy, John

2016-01-01

Many algorithms for scientific visualization and image analysis are rooted in the world of continuous scalar, vector, and tensor fields, but are programmed in low-level languages and libraries that obscure their mathematical foundations. Diderot is a parallel domain-specific language that is designed to bridge this semantic gap by providing the programmer with a high-level, mathematical programming notation that allows direct expression of mathematical concepts in code. Furthermore, Diderot provides parallel performance that takes advantage of modern multicore processors and GPUs. The high-level notation allows a concise and natural expression of the algorithms and the parallelism allows efficient execution on real-world datasets.

Development of LRFD design procedures for bridge piles in Iowa : field testing of steel H-piles in clay, sand, and mixed soils and data analysis (volume II).

DOT National Transportation Integrated Search

2011-09-01

In response to the mandate on Load and Resistance Factor Design (LRFD) implementations by the Federal Highway Administration : (FHWA) on all new bridge projects initiated after October 1, 2007, the Iowa Highway Research Board (IHRB) sponsored these r...

An Ontology-Based Framework for Bridging Learning Design and Learning Content

ERIC Educational Resources Information Center

Knight, Colin, Gasevic, Dragan; Richards, Griff

2006-01-01

The paper describes an ontology-based framework for bridging learning design and learning object content. In present solutions, researchers have proposed conceptual models and developed tools for both of those subjects, but without detailed discussions of how they can be used together. In this paper we advocate the use of ontologies to explicitly…

Building a Straw Bridge

ERIC Educational Resources Information Center

Teaching Science, 2015

2015-01-01

This project is for a team of students (groups of two or three are ideal) to design and construct a model of a single-span bridge, using plastic drinking straws as the building material. All steps of the design, construction, testing and critiquing stages should be recorded by students in a journal. Students may like to include labelled diagrams,…

Learning Based on the Project Entitled "Design and Construction of a Wooden Bridge"

ERIC Educational Resources Information Center

Barris, Cristina; Torres, Lluís; Simon, Enric

2016-01-01

This article presents the results of a case involving the application of project-based learning carried out with students in the Mechanical Engineering degree program at the University of Girona. The project, entitled "Design and construction of a wooden bridge", was conducted at the Polytechnic School in the third-year Structures…

Evaluating fire-damaged components of historic covered bridges

Treesearch

Brian Kukay; Charles Todd; Tyler Jahn; Jenson Sannon; Logan Dunlap; Robert White; Mark Dietenberger

2016-01-01

Arson continues to claim many historic covered bridges. Site-specific, post-fire evaluations of the structural integrity of a bridge are often necessary in a fire’s aftermath. Decisions on whether individual wood components can be rehabilitated, reconstructed, or replaced must be made. This report includes coverage of existing approaches and exploratory approaches that...

Inhibition of Bacterial Rna Polymerase by Streptolydigin: Stabilization of A Straight-Bridge-Helix Active-Center Conformation

PubMed Central

Tuske, Steven; Sarafianos, Stefan G.; Wang, Xinyue; Hudson, Brian; Sineva, Elena; Mukhopadhyay, Jayanta; Birktoft, Jens J.; Leroy, Olivier; Ismail, Sajida; Clark, Arthur D.; Dharia, Chhaya; Napoli, Andrew; Laptenko, Oleg; Lee, Jookyung; Borukhov, Sergei; Ebright, Richard H.; Arnold, Eddy

2009-01-01

We define the target, mechanism, and structural basis of inhibition of bacterial RNA polymerase (RNAP) by the tetramic-acid antibiotic streptolydigin (Stl). Stl binds to a site adjacent to, but not overlapping, the RNAP active center and stabilizes an RNAP-active-center conformational state with a straight bridge helix. The results provide direct support for the proposals that alternative straight-bridge-helix and bent-bridge-helix RNAP-active-center conformations exist, and that cycling between straight-bridge-helix and bent-bridge-helix RNAP-active-center conformations is required for RNAP function. The results set bounds on models for RNAP function and suggest strategies for design of novel antibacterial agents. PMID:16122422

Theoretical mechanics: crowd synchrony on the Millennium Bridge.

PubMed

Strogatz, Steven H; Abrams, Daniel M; McRobie, Allan; Eckhardt, Bruno; Ott, Edward

2005-11-03

Soon after the crowd streamed on to London's Millennium Bridge on the day it opened, the bridge started to sway from side to side: many pedestrians fell spontaneously into step with the bridge's vibrations, inadvertently amplifying them. Here we model this unexpected and now notorious phenomenon--which was not due to the bridge's innovative design as was first thought--by adapting ideas originally developed to describe the collective synchronization of biological oscillators such as neurons and fireflies. Our approach should help engineers to estimate the damping needed to stabilize other exceptionally crowded footbridges against synchronous lateral excitation by pedestrians.

Combined collapse by bridging and self-adhesion in a prototypical polymer model inspired by the bacterial nucleoid

NASA Astrophysics Data System (ADS)

Scolari, Vittore F.; Cosentino Lagomarsino, Marco

Recent experimental results suggest that the E. coli chromosome feels a self-attracting interaction of osmotic origin, and is condensed in foci by bridging interactions. Motivated by these findings, we explore a generic modeling framework combining solely these two ingredients, in order to characterize their joint effects. Specifically, we study a simple polymer physics computational model with weak ubiquitous short-ranged self attraction and stronger sparse bridging interactions. Combining theoretical arguments and simulations, we study the general phenomenology of polymer collapse induced by these dual contributions, in the case of regularly-spaced bridging. Our results distinguish a regime of classical Flory-like coil-globule collapse dictated by the interplay of excluded volume and attractive energy and a switch-like collapse where bridging interaction compete with entropy loss terms from the looped arms of a star-like rosette. Additionally, we show that bridging can induce stable compartmentalized domains. In these configurations, different "cores" of bridging proteins are kept separated by star-like polymer loops in an entropically favorable multi-domain configuration, with a mechanism that parallels micellar polysoaps. Such compartmentalized domains are stable, and do not need any intra-specific interactions driving their segregation. Domains can be stable also in presence of uniform attraction, as long as the uniform collapse is above its theta point.

Study on bridge checking evaluation based on deformation-Stress data

NASA Astrophysics Data System (ADS)

Shi, Jing Xian; Cheng, Ying Jie

2018-06-01

Bridge structure plays a very important role in human traffic. The evaluation of bridge structure after a certain period of operation has always been the focus of the bridge. Based on the data collected from the health inspection system of a continuous rigid frame bridge on a highway in Yunnan, China, it is found that there is a certain linear relationship between the deformation and stress of the bridge structure. In view of a specific section of the structure, the stress value of this section can be derived according to its deformation value. The coefficient K can be calculated by comparing the estimated value to the actual measured value. According to the range of the K value, the structural state of the bridge can be evaluated to a certain extent.

50 CFR 17.108 - List of designated manatee protection areas.

Code of Federal Regulations, 2013 CFR

2013-10-01

... the Granada Bridge (State Road 40) (including the Tomoka Basin), a distance of approximately 5.0 km (3... feet) north to 305 meters (1,000 feet) south of the Granada Bridge (State Road 40), a distance of... point 305 meters (1,000 feet) south of the Granada Bridge (State Road 40) to a point 152 meters (500...

50 CFR 17.108 - List of designated manatee protection areas.

Code of Federal Regulations, 2014 CFR

2014-10-01

... the Granada Bridge (State Road 40) (including the Tomoka Basin), a distance of approximately 5.0 km (3... feet) north to 305 meters (1,000 feet) south of the Granada Bridge (State Road 40), a distance of... point 305 meters (1,000 feet) south of the Granada Bridge (State Road 40) to a point 152 meters (500...

50 CFR 17.108 - List of designated manatee protection areas.

Code of Federal Regulations, 2012 CFR

2012-10-01

... the Granada Bridge (State Road 40) (including the Tomoka Basin), a distance of approximately 5.0 km (3... feet) north to 305 meters (1,000 feet) south of the Granada Bridge (State Road 40), a distance of... point 305 meters (1,000 feet) south of the Granada Bridge (State Road 40) to a point 152 meters (500...

Covered Bridge Security Manual

Treesearch

Brett Phares; Terry Wipf; Ryan Sievers; Travis Hosteng

2013-01-01

The design, construction, and use of covered timber bridges is all but a lost art in these days of pre-stressed concrete, high-performance steel, and the significant growth both in the volume and size of vehicles. Furthermore, many of the existing covered timber bridges are preserved only because of their status on the National Registry of Historic Places or the...

Learning Bridges: A Role for Mobile Technologies in Education

ERIC Educational Resources Information Center

Vavoula, Giasemi; Sharples, Mike; Lonsdale, Peter; Rudman, Paul; Meek, Julia

2007-01-01

MyArtSpace is a service for children to spread their learning between schools and museums using mobile phones linked to a personal Web space. Using MyArtSpace as an example, the authors discuss the possibilities for mobile technology to form bridges between formal and informal learning. They also offer guidelines for designing such bridges.…

Comparative durability of timber bridges in the USA

Treesearch

James P. Wacker; Brian K. Brashaw

2017-01-01

As engineers begin to utilize life-cycle-cost design approaches for timber bridges, there is a necessity for more reliable data about their durability and expected service life. This paper summarizes a comprehensive effort to assess the current condition of more than one hundred timber highway bridge superstructures throughout the United States. This national study was...

Overview of the national historic covered bridge preservation (NHCBP) program

Treesearch

James P. Wacker; Sheila Rimal Duwadi

2010-01-01

Covered wooden bridges proliferated in the United States in the mid-nineteenth century. Today an estimated 800 covered bridge structures remain, but they are nevertheless cherished links to the technological heritage of the United States. The through-truss designs vary from the Kingpost trusses built in the craft tradition to the engineered Burr arch and Paddleford...

Composite action in a steel girder span with precast deck panels : the I-81 bridge over the New River in Radford, Virginia.

DOT National Transportation Integrated Search

2003-01-01

Two parallel bridges carry I-81 north and south over the New River in southwest Virginia, near the city of Radford. The bridges are identical in design and have been in place since 1985. In recent years, a number of maintenance issues have been repor...

Managing Transitions, Building Bridges: An Evaluation of a Summer Bridge Program for African American Scientists and Engineers

ERIC Educational Resources Information Center

Johnson, Jennifer Michelle

2016-01-01

Purpose: This paper aims to highlight the potential of science, technology, engineering and mathematics (STEM) summer bridge programs to promote college persistence by fostering a positive science identity among participants that is culturally consistent with the values and experiences of African American students. Design/methodology/approach:…

Service life assessment of timber highway bridges in USA climate zones

Treesearch

James P. Wacker; Brian K. Brashaw; Thomas G. Williamson; P. David Jones; Matthew S. Smith; Travis K. Hosteng; David L. Strahl; Lola E. Coombe; V.J. Gopu

2014-01-01

As engineers begin to estimate life-cycle costs and sustainable design approaches for timber bridges, there is a need for more reliable data about their durability and expected service life. This paper summarizes a comprehensive effort to assess the current condition of more than one hundred timber highway bridge superstructures throughout the United States. This...

Integrating modal-based NDE techniques and bridge management systems using quality management

NASA Astrophysics Data System (ADS)

Sikorsky, Charles S.

1997-05-01

The intent of bridge management systems is to help engineers and managers determine when and where to spend bridge funds such that commerce and the motoring public needs are satisfied. A major shortcoming which states are experiencing is the NBIS data available is insufficient to perform certain functions required by new bridge management systems, such as modeling bridge deterioration and predicting costs. This paper will investigate how modal based nondestructive damage evaluation techniques can be integrated into bridge management using quality management principles. First, quality from the manufacturing perspective will be summarized. Next, the implementation of quality management in design and construction will be reinterpreted for bridge management. Based on this, a theory of approach will be formulated to improve the productivity of a highway transportation system.

Effectiveness of a Short, Intense Bridging Course for Scaffolding Students Commencing University-level Study of Chemistry

NASA Astrophysics Data System (ADS)

Schmid, Siegbert; Youl, David J.; George, Adrian V.; Read, Justin R.

2012-05-01

Bridging courses designed to support students commencing tertiary education are widespread, and some evidence for the value of semester-length courses has been reported; however, little attention has been paid to short-but-intense bridging courses, and empirical evidence of their effectiveness is particularly sparse. The current study followed the academic performance of a cohort of students enrolled in a first-year chemistry unit of study designed for those with little or no background knowledge of chemistry. The aims of this study are two-fold: first to determine the strength of the linkage between prior knowledge in chemistry and performance on the end of semester exam, and secondly, to explore the reasons for any differences observed. In particular, the value of the week-long intensive-mode bridging course offered by the University of Sydney was analysed. Quantitative and qualitative data were collected. The research has shown that participation in the chemistry bridging course is associated with 'bridging the gap' in academic performance between students with No Prior Chemistry background and those with a Strong Background. While the content of the bridging course is a significant contributor to academic success, so too is the confidence in their own learning that the course engenders among participants.

Frequency Modulation and Absorption Improvement of THz Micro-bolometer with Micro-bridge Structure by Spiral-Type Antennas

NASA Astrophysics Data System (ADS)

Gou, Jun; Niu, Qingchen; Liang, Kai; Wang, Jun; Jiang, Yadong

2018-03-01

Antenna-coupled micro-bridge structure is proven to be a good solution to extend infrared micro-bolometer technology for THz application. Spiral-type antennas are proposed in 25 μm × 25 μm micro-bridge structure with a single separate linear antenna, two separate linear antennas, or two connected linear antennas on the bridge legs, in addition to traditional spiral-type antenna on the support layer. The effects of structural parameters of each antenna on THz absorption of micro-bridge structure are discussed for optimized absorption of 2.52 THz wave radiated by far infrared CO2 lasers. The design of spiral-type antenna with two separate linear antennas for wide absorption peak and spiral-type antenna with two connected linear antennas for relatively stable absorption are good candidates for high absorption at low absorption frequency with a rotation angle of 360* n ( n = 1.6). Spiral-type antenna with extended legs also provides a highly integrated micro-bridge structure with fast response and a highly compatible, process-simplified way to realize the structure. This research demonstrates the design of several spiral-type antenna-coupled micro-bridge structures and provides preferred schemes for potential device applications in room temperature sensing and real-time imaging.

Frequency Modulation and Absorption Improvement of THz Micro-bolometer with Micro-bridge Structure by Spiral-Type Antennas.

PubMed

Gou, Jun; Niu, Qingchen; Liang, Kai; Wang, Jun; Jiang, Yadong

2018-03-05

Antenna-coupled micro-bridge structure is proven to be a good solution to extend infrared micro-bolometer technology for THz application. Spiral-type antennas are proposed in 25 μm × 25 μm micro-bridge structure with a single separate linear antenna, two separate linear antennas, or two connected linear antennas on the bridge legs, in addition to traditional spiral-type antenna on the support layer. The effects of structural parameters of each antenna on THz absorption of micro-bridge structure are discussed for optimized absorption of 2.52 THz wave radiated by far infrared CO 2 lasers. The design of spiral-type antenna with two separate linear antennas for wide absorption peak and spiral-type antenna with two connected linear antennas for relatively stable absorption are good candidates for high absorption at low absorption frequency with a rotation angle of 360*n (n = 1.6). Spiral-type antenna with extended legs also provides a highly integrated micro-bridge structure with fast response and a highly compatible, process-simplified way to realize the structure. This research demonstrates the design of several spiral-type antenna-coupled micro-bridge structures and provides preferred schemes for potential device applications in room temperature sensing and real-time imaging.

In vitro validation of a shape-optimized fiber-reinforced dental bridge.

PubMed

Chen, YungChung; Li, Haiyan; Fok, Alex

2011-12-01

To improve its mechanical performance, structural optimization had been used in a previous study to obtain an alternative design for a 3-unit inlay-retained fiber-reinforced composite (FRC) dental bridge. In that study, an optimized layout of the FRC substructure had been proposed to minimize stresses in the veneering composite and interfacial stresses between the composite and substructure. The current work aimed to validate in vitro the improved fracture resistance of the optimized design. All samples for the 3-unit inlay-retained FRC dental bridge were made with glass-fibers (FibreKor) as the substructure, surrounded by a veneering composite (GC Gradia). Two different FRC substructure designs were prepared: a conventional (n=20) and an optimized design (n=21). The conventional design was a straight beam linking one proximal box to the other, while the optimized design was a curved beam following the lower outline of the pontic. All samples were loaded to 400N on a universal test machine (MTS 810) with a loading speed of 0.2mm/min. During loading, the force and displacement were recorded. Meanwhile, a two-channel acoustic emission (AE) system was used to monitor the development of cracks during loading. The load-displacement curves of the two groups displayed significant differences. For the conventional design, there were numerous drops in load corresponding to local damage of the sample. For the optimized design, the load curves were much smoother. Cracks were clearly visible on the surface of the conventional group only, and the directions of those cracks were perpendicular to those of the most tensile stresses. Results from the more sensitive AE measurement also showed that the optimized design had, on average, fewer cracking events: 38 versus 2969 in the conventional design. The much lower number of AE events and smoother load-displacement curves indicated that the optimized FRC bridge design had a higher fracture resistance. It is expected that the optimized design will significantly improve the clinical performance of FRC bridges. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Polymeric salt bridges for conducting electric current in microfluidic devices

DOEpatents

Shepodd, Timothy J [Livermore, CA; Tichenor, Mark S [San Diego, CA; Artau, Alexander [Humacao, PR

2009-11-17

A "cast-in-place" monolithic microporous polymer salt bridge for conducting electrical current in microfluidic devices, and methods for manufacture thereof is disclosed. Polymeric salt bridges are formed in place in capillaries or microchannels. Formulations are prepared with monomer, suitable cross-linkers, solvent, and a thermal or radiation responsive initiator. The formulation is placed in a desired location and then suitable radiation such as UV light is used to polymerize the salt bridge within a desired structural location. Embodiments are provided wherein the polymeric salt bridges have sufficient porosity to allow ionic migration without bulk flow of solvents therethrough. The salt bridges form barriers that seal against fluid pressures in excess of 5000 pounds per square inch. The salt bridges can be formulated for carriage of suitable amperage at a desired voltage, and thus microfluidic devices using such salt bridges can be specifically constructed to meet selected analytical requirements.

The Functional Role of eL19 and eB12 Intersubunit Bridge in the Eukaryotic Ribosome.

PubMed

Kisly, Ivan; Gulay, Suna P; Mäeorg, Uno; Dinman, Jonathan D; Remme, Jaanus; Tamm, Tiina

2016-05-22

During translation, the two eukaryotic ribosomal subunits remain associated through 17 intersubunit bridges, five of which are eukaryote specific. These are mainly localized to the peripheral regions and are believed to stabilize the structure of the ribosome. The functional importance of these bridges remains largely unknown. Here, the essentiality of the eukaryote-specific bridge eB12 has been investigated. The main component of this bridge is ribosomal protein eL19 that is composed of an N-terminal globular domain, a middle region, and a long C-terminal α-helix. The analysis of deletion mutants demonstrated that the globular domain and middle region of eL19 are essential for cell viability, most likely functioning in ribosome assembly. The eB12 bridge, formed by contacts between the C-terminal α-helix of eL19 and 18S rRNA in concert with additional stabilizing interactions involving either eS7 or uS17, is dispensable for viability. Nevertheless, eL19 mutants impaired in eB12 bridge formation displayed slow growth phenotypes, altered sensitivity/resistance to translational inhibitors, and enhanced hyperosmotic stress tolerance. Biochemical analyses determined that the eB12 bridge contributes to the stability of ribosome subunit interactions in vitro. 60S subunits containing eL19 variants defective in eB12 bridge formation failed to form 80S ribosomes regardless of Mg(2+) concentration. The reassociation of 40S and mutant 60S subunits was markedly improved in the presence of deacetylated tRNA, emphasizing the importance of tRNAs during the subunit association. We propose that the eB12 bridge plays an important role in subunit joining and in optimizing ribosome functionality. Copyright © 2016 Elsevier Ltd. All rights reserved.

Identification of damping in a bridge using a moving instrumented vehicle

NASA Astrophysics Data System (ADS)

González, A.; OBrien, E. J.; McGetrick, P. J.

2012-08-01

In recent years, there has been a significant increase in the number of bridges which are being instrumented and monitored on an ongoing basis. This is in part due to the introduction of bridge management systems designed to provide a high level of protection to the public and early warning if the bridge becomes unsafe. This paper investigates a novel alternative; a low-cost method consisting of the use of a vehicle fitted with accelerometers on its axles to monitor the dynamic behaviour of bridges. A simplified half-car vehicle-bridge interaction model is used in theoretical simulations to test the effectiveness of the approach in identifying the damping ratio of the bridge. The method is tested for a range of bridge spans and vehicle velocities using theoretical simulations and the influences of road roughness, initial vibratory condition of the vehicle, signal noise, modelling errors and frequency matching on the accuracy of the results are investigated.

Construction Simulation Analysis of 60m-span Concrete Filled Steel Tube arch bridge

NASA Astrophysics Data System (ADS)

Shi, Jing Xian; Ding, Qing Hua

2018-06-01

The construction process of the CFST arch bridge is complicated. The construction process not only affects the structural stress in the installation, but also determines the form a bridge and internal force of the bridge. In this paper, a 60m span concrete filled steel tube tied arch bridge is taken as the background, and a three-dimensional finite element simulation model is established by using the MIDAS/Civil bridge structure analysis software. The elevation of the main arch ring, the beam stress, the forces in hanger rods and the modal frequency of the main arch during the construction stage are calculated, and the construction process is simulated and analyzed. Effectively and reasonably guide the construction and ensure that the line and force conditions of the completed bridge meet the design requirements and provides a reliable technical guarantee for the safe construction of the bridge.

33 CFR 117.1089 - Manitowoc River.

Code of Federal Regulations, 2013 CFR

2013-07-01

... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Wisconsin § 117.1089 Manitowoc River. (a) The draws of... between the two bridges. (b) The draw of the Wisconsin Central railroad bridge, mile 0.91 at Manitowoc...

33 CFR 117.1089 - Manitowoc River.

Code of Federal Regulations, 2014 CFR

2014-07-01

... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Wisconsin § 117.1089 Manitowoc River. (a) The draws of... between the two bridges. (b) The draw of the Wisconsin Central railroad bridge, mile 0.91 at Manitowoc...

33 CFR 117.1089 - Manitowoc River.

Code of Federal Regulations, 2012 CFR

2012-07-01

... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Wisconsin § 117.1089 Manitowoc River. (a) The draws of... between the two bridges. (b) The draw of the Wisconsin Central railroad bridge, mile 0.91 at Manitowoc...

33 CFR 117.1089 - Manitowoc River.

Code of Federal Regulations, 2011 CFR

2011-07-01

... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Wisconsin § 117.1089 Manitowoc River. (a) The draws of... between the two bridges. (b) The draw of the Wisconsin Central railroad bridge, mile 0.91 at Manitowoc...

33 CFR 117.1089 - Manitowoc River.

Code of Federal Regulations, 2010 CFR

2010-07-01

... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Wisconsin § 117.1089 Manitowoc River. (a) The draws of... between the two bridges. (b) The draw of the Wisconsin Central railroad bridge, mile 0.91 at Manitowoc...

Automated analysis of long-term bridge behavior and health using a cyber-enabled wireless monitoring system

NASA Astrophysics Data System (ADS)

O'Connor, Sean M.; Zhang, Yilan; Lynch, Jerome; Ettouney, Mohammed; van der Linden, Gwen

2014-04-01

A worthy goal for the structural health monitoring field is the creation of a scalable monitoring system architecture that abstracts many of the system details (e.g., sensors, data) from the structure owner with the aim of providing "actionable" information that aids in their decision making process. While a broad array of sensor technologies have emerged, the ability for sensing systems to generate large amounts of data have far outpaced advances in data management and processing. To reverse this trend, this study explores the creation of a cyber-enabled wireless SHM system for highway bridges. The system is designed from the top down by considering the damage mechanisms of concern to bridge owners and then tailoring the sensing and decision support system around those concerns. The enabling element of the proposed system is a powerful data repository system termed SenStore. SenStore is designed to combine sensor data with bridge meta-data (e.g., geometric configuration, material properties, maintenance history, sensor locations, sensor types, inspection history). A wireless sensor network deployed to a bridge autonomously streams its measurement data to SenStore via a 3G cellular connection for storage. SenStore securely exposes the bridge meta- and sensor data to software clients that can process the data to extract information relevant to the decision making process of the bridge owner. To validate the proposed cyber-enable SHM system, the system is implemented on the Telegraph Road Bridge (Monroe, MI). The Telegraph Road Bridge is a traditional steel girder-concrete deck composite bridge located along a heavily travelled corridor in the Detroit metropolitan area. A permanent wireless sensor network has been installed to measure bridge accelerations, strains and temperatures. System identification and damage detection algorithms are created to automatically mine bridge response data stored in SenStore over an 18-month period. Tools like Gaussian Process (GP) regression are used to predict changes in the bridge behavior as a function of environmental parameters. Based on these analyses, pertinent behavioral information relevant to bridge management is autonomously extracted.

Improved bridge joint materials and design details.

DOT National Transportation Integrated Search

2017-06-01

Expansion joints accommodate bridge movements that result from factors such as thermal expansion and contraction, concrete shrinkage, creep effects, live loading, settlement of the foundation and substructure, and environmental stressors. Expansion j...

Key Royale bridge five year evaluation.

DOT National Transportation Integrated Search

2013-06-01

This report describes the design, construction, instrumentation, and five-year evaluation of the Key Royale Bridge substructure. The primary focus was the evaluation of the implementation of highly reactive supplementary cementitious materials (SCM) ...