Publication Abstract

Proceedings of the Deep Mixing 2015 Conference, (DFI)

Measurements of CDSM Strengths and Seepage Data Following Seismic Upgrades of San Pablo Dam
Robert C. Kirby, G.E., Terra Engineers, United States; Sean M. Todaro, G.E., East Bay Municipal Utility District, United States; Atta B. Yiadom, G.E., East Bay Municipal Utility District, United States; A. David Miller, P. E., Raito, Inc., United States

San Pablo Dam is a 170-foot (52-meter)-high earthfill embankment, located approximately 10 miles (16 kilometers) north of downtown Oakland, California, that impounds a 38,600 acre-feet (47.6 million m3) reservoir for customers in the East Bay Municipal Utility District's (EBMUD's) service area. Seismic upgrades were designed and constructed in 2008 through 2010. Work included removal of an existing 140,000 cubic-yard (107,000 m3) downstream buttress, which was replaced with an enlarged 300,000 cubic-yard (230,000 m3) buttress founded on alluvium and colluvium that were improved in-place using Cement Deep Soil Mixing (CDSM) technology. The site characterization for the project, design of CDSM, reuse of CDSM spoils as construction materials, and environmental permitting have been described in five previously published professional papers. This paper provides a brief summary of the design of the seismic upgrades and presents the results of measurements made during and/or after construction including the variation of CDSM strengths with time, piezometric levels within the dam and foundation soils, and seepage flow rates. These measured values are compared to the values estimated during design of the seismic upgrades.

 article #2127; publication #1013 (DM-2015)