Bridge Projects
San Francisco-Oakland Bay Bridge East Span Replacement




The New East Span of the San Francisco-Oakland Bay Bridge (SFOBB) replaced the 70-year-old steel truss structure, a portion of which had collapsed during the 1989 Loma Prieta Earthquake. The new bridge is divided into (1) the Yerba Buena Island (YBI) transition structure, (2) Self-Anchored Suspension (SAS) bridge, (3) Skyway structure viaduct, and (4) Oakland approach structure (OTD). It was opened on Labor Day of 2013.

EMI in a joint venture with Fugro West were the geotechnical engineer of record for the entire bay bridge from 1998 to 2014. EMI's project group consisted of renowned seismologists, geologists, and geotechnical engineers. Fugro-EMI conducted large-scale geotechnical soil and rock explorations overwater and on land at the YBI and OTD approaches. Challenges included variable ground conditions, hard rock and soft soils, and steep hillside terrain. EMI led a study of controlled rock blasting to develop project specifications for West Pier construction. All work was under peer review.

Foundation design challenges included high seismicity, hard rock and soft bay mud soils, soil and rock slope stability, constructibility, and lateral ground settlement and spreading. Bridge foundations included large-diameter driven steel piles and cast-in-drilled hole piles. EMI employed state-of-the-art site-response and kinematic soil-pile interaction analyses to establish multiple-support design ground motions.

EMI provided geotechnical support to complex foundation construction at both approaches and is currently providing design and construction support on auxiliary projects for the San Francisco County and Bay Area Toll Authority and Caltrans.

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