SEISMIC RESPONSE OF SOIL DEPOSITS IN SAN-FRANCISCO MARINA DISTRICT

This paper presents an application of the effective stress based, full y coupled, nonlinear numerical procedure DYSAC2 and the total stress-b ased, equivalent-linear procedure SHAKE to the analysis of the seismic response of soil deposits in the San Francisco marina district. A dyn amic centrifuge model test was performed using subsurface conditions s imilar to those found in the marina district to evaluate the predictio ns made by DYSAC2 and SHAKE, Three sites in the marina district were s elected for site investigations and analyses. The first site showed no indications of soil liquefaction and no building damage. The second s ite showed no indication of liquefaction either, yet considerable buil ding damage was observed in the vicinity. At the third site, surface m anifestations of liquefaction were observed in addition to considerabl e damage to neighboring buildings. The dynamic behavior of these three sites was evaluated using DYSAC2 and SHAKE. The results of this analy sis are presented and are compared to the observed behavior in the mar ina district during the Loma Prieta earthquake. Discrepancies between the DYSAC2 and SHAKE predictions are also discussed.