Geotechnical drilling was set to begin yesterday on the 710 Tunnel Technical Study in the L.A. area. Currently the 710 freeway ends along the city of Los Angeles-Alhambra boundary but was intended to run north to a junction with the 210 and 134 in Pasadena. The tunnel technical study will assess the feasibility of building a tunnel to complete the segment. Caltrans and CH2M HILL will be performing the borings which will go up to 250-ft deep. Seismic lines will be performed as a part of the study as well. Source: LA Times.
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).
The proposed tunnel to replace the seismically deficient Alaskan Way Viaduct in Downtown Seattle is no stranger to controversy. This article highlights recent discussions regarding the cost of the project. Washington Governor Chris Gregoire declared […]