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Tectonics and Ancient Civilizations
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Project Related
The Claremont Tunnel – Designed to Survive Fault Rupture on the Hayward Fault
The Claremont tunnel beneath the Berkeley Hills on the east side of Oakland is a water supply tunnel that serves over 800,000 customers in Richmond, Oakland, San Leandro and neighboring communities. One of the unique things about the tunnel is that it crosses the active Hayward Fault. Most of the time when you talk about designing for earthquakes you’re talking about designing to withstand the seismic forces. In this case, the designers needed the water transmission tunnel to withstand up to 7.5-ft of offset due to fault slip and still maintain a minimum level of service. (Photo credit: Sue Bednarz, Jacobs Associates, Inc. by way of Civil Engineering Magazine)
This post describes the relatively recent Claremont Tunnel Seismic Upgrade Project as reported in Civil Engineering Magazine (May 2008, v. 78, no. 5, pp 58-63, 96-97).
Geologic Hazards
Trenching on Weber Segment of Wasatch Fault
The Salt Lake Tribune published an article recently on some trenching activity by the Utah Geologic Survey and the USGS to better date past movements on this active fault.
General
Geologists Recover Pieces of San Andreas Fault from 2 Miles Deep
As a follow up to a previous post, the San Andreas Fault Observatory at Depth (SAFOD) team has announced that they have successfully completed their drilling and obtained cores of the San Andreas Fault at depths in excess of 2 miles below the surface. The zone of interest is approximately 135-ft in length. The core size is 4-in diameter. They have cemented in a 7-in casing and the next phase of the project will be to perforate the casing within the fault and install monitoring equipment consisting of seismometers, accelerometers, tiltmeters and a fluid pressure transducer. Read on for more info and links. (Image credit: EarthScope / NSF)