Development of Seismic Ground Motion Criteria for New San Francisco–Oakland Bay Bridge

This paper presents development of seismic design criteria for the San Francisco-Oakland Bay Bridge (SFOBB) East Span Replacement Project. Probabilistic Seismic Hazard Analysis (PSHA) was used to establish the basic rock motion criteria; the 1,500-year and 92-year return periods were adopted for the Safety Evaluation Earthquake (SEE) and Functional Evaluation Earthquake (FEE) ground motions. The preliminary design of the bridge was conducted with a response spectrum approach and was checked against six sets of time histories. The ARS design curves and time histories used for dynamic analyses of the structure were derived from the considerations of wave propagation in soil sediments and soil-pile interactions. Near-fault directivity effects and incoherency of ground motions were considered.