Seismic Response of Soil Deposits in San Francisco Marina District

Abstract

This paper presents an application of the effective stress based, fully coupled, nonlinear numerical procedure DYSAC2 and the total stress-based, equivalent-linear procedure SHAKE to the analysis of the seismic response of soil deposits in the San Francisco marina district. A dynamic centrifuge model test was performed using subsurface conditions similar to those found in the marina district to evaluate the predictions made by DYSAC2 and SHAKE. Three sites in the marina district were selected for site investigations and analyses. The first site showed no indications of soil liquefaction and no building damage. The second site showed no indication of liquefaction either, yet considerable building damage was observed in the vicinity. At the third site, surface manifestations of liquefaction were observed in addition to considerable damage to neighboring buildings. The dynamic behavior of these three sites was evaluated using DYSAC2 and SHAKE. The results of this analysis are presented and are compared to the observed behavior in the marina district during the Loma Prieta earthquake. Discrepancies between the DYSAC2 and SHAKE predictions are also discussed.