1991-08-01
cracking in earth dams commonly occurs by hydraulic fracturing . Hydraulic fracturing is a tensile separation along an internal surface in a 25 soil mass...stress. This hydraulic fracturing is facilitated by differential settle- ment and internal stress transfer in an earthen structure. Sherard also showed...the hydraulic fracturing . 42. BioLic activity, i.e., the actions of plant roots and burrowing animals, has provided a popular explanation for pipe
[The court physician, the clergyman, a learned society and smallpox].
Hillen, H F P
2017-01-01
Variolation was introduced in England in the first half of the 18th century. The positive effects of this new method for preventing smallpox were already known in the Netherlands around 1720, one of whom was the Dutch physician Boerhaave. In spite of this, it took another 30 years before variolation was used in the Netherlands. Despite receiving positive advice and information from his learned English friends Sloane and Sherard, Boerhaave did not apply nor advise the use of variolation. There were various arguments for this restrained approach. In 1754 Thomas Schwencke found that conditions were favourable for the introduction of variolation in The Hague. There was support from the House of Orange-Nassau (the current royal family in the Netherlands) and from a learned society; a highly motivated clergyman acted as ambassador for the new technique and the court physician Schwencke was willing to take the lead. A similar combination had previously been effective in England, though the ambassador there was not a clergyman but an influential noble lady.
Tectonic creep in the Hayward fault zone, California
Radbruch-Hall, Dorothy H.; Bonilla, M.G.
1966-01-01
Tectonic creep is slight apparently continuous movement along a fault. Evidence of creep has been noted at several places within the Hayward fault zone--a zone trending northwestward near the western front of the hills bordering the east side of San Francisco Bay. D. H. Radbruch of the Geological Survey and B. J. Lennert, consulting engineer, confirmed a reported cracking of a culvert under the University of California stadium. F. B. Blanchard and C. L. Laverty of the East Bay Municipal Utility District of Oakland studied cracks in the Claremont water tunnel in Berkeley. M. G. Bonilla of the Geological Survey noted deformation of railroad tracks in the Niles district of Fremont. Six sets of tracks have been bent and shifted. L. S. Cluff of Woodward-Clyde-Sherard and Associates and K. V. Steinbrugge of the Pacific Fire Rating Bureau noted that the concrete walls of a warehouse in the Irvington district of Fremont have been bent and broken, and the columns forced out of line. All the deformations noted have been right lateral and range from about 2 inches in the Claremont tunnel to about 8 inches on the railroad tracks. Tectonic creep almost certainly will continue to damage buildings, tunnels, and other structures that cross the narrow bands of active movement within the Hayward fault zone.