Restraining Post-Liquefaction Flow Deformations. Phase 3

摘要

A simplified nonlinear 3-D model is used to study the seismic response of pilegroups. The method is validated for elastic analyses using existing exact solutions for small pile groups. Centrifuge data on the response of model pile groups in sand under strong shaking are used to verify the capability of the program to model the nonlinear response of pile groups. The program is used to evaluate a full-scale field test on a 6x6 pile group supporting a large transformer bank at the Duwamish Substation in Seattle, Washington. A novel feature of the method is that the time histories of lateral, rotational and coupled stiffnesses and corresponding damping factors for pile groups can be determined. This type of information is very useful when one is forced to select discrete springs and dashpots for use in commercial structural engineering programs for the analysis of structures on pile foundations such as bridges and tall buildings under earthquake loading.