CMS-9714858, C.B. Crouse, Dames & Moore The strong ground shaking recorded at the Jensen Filtration Plant during the 1994 Northridge earthquake sequence (mainshock and aftershocks) offers a unique opportunity to study soil nonlinearity. Two accelerographs stations close together at the Jensen Filtration Plant in California recorded the earthquake motions; one station was situated over moderately stiff soil, the other on very stiff soil. The character of the two recordings -- which were quite different -- suggests that nonlinear soil response could have been significant at the moderately stiff soil site during the mainshock. However the two buildings containing station accelerographs at this site were also different, which raises the concern whether soil- structure interaction affected the motions at one or both stations. Thus the objective of this study is to investigate the influence of soil-structure interaction on the recordings. Two Federal agencies are collaborating in the support of this project: the US Geological Survey and the National Science Foundation.
