‘The Santa Clara Valley Water District has received preliminary findings from an ongoing seismic stability evaluation for Anderson Dam that detail part of the dam could experience “significant slumping” if a 7.25 magnitude earthquake were to occur on the Calaveras Fault within about a mile of the dam.’ [Source: MorganHillTimes.com via Association of State Dam Safety Officials]
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 youâ€™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).