Three-Dimensional Numerical Investigation on Seismic Response of Subway Station in Liquefied Soil by the Loosely Coupled Effective Stress Model

Abstract

Three-dimensional numerical simulation for clarifying the seismic response characteristics of an underground structure considering the influences of dynamic interaction with the surrounding liquefied soil is still a huge challenge. Using the proposed generic loosely coupled nonlinear effective stress method for site response of liquefiable soil, the authors developed an effective stress seismic response analysis of the underground subway station structure. Based on the effective stress method, the responses of the model underground subway station with three floors and three spans in model liquefiable foundation in the shaking table test are simulated. The comparison between the measured and simulated results proves that the developed method can effectively capture the response characteristics of the liquefiable foundation，by which the generation of residual excess pore water pressure and the effect of cyclic stiffness softening and degradation can be taken into good consideration, and the measured responses of model underground structure can be well reproduced. The results also demonstrate the availability of the shaking table test simulating the dynamic interaction between the underground structure and the surrounding liquefied soil.