Study on Seismic Response of Underground Structure in Saturated Soil Deposit Based on OpenSees
Using the finite element calculation software OpenSees,this study focuses on a subway station structure as the primary analysis object while establishing an operational seismic response model for a saturated soil-underground structural system.This model enables a systematic calculation of the seismic response.The study considers the dynamic response of the saturated soil on site as a near-field fluctuation problem of a saturated two-phase medium.A time-domain explicit numerical algorithm is employed for calculations,incorporating the elastic-plastic dynamic response characteristics of the soil.The results of this study indicate several key findings:(1)The elastic-plastic dynamic response characteristics of the site soil are accounted for during the simulation analysis.This considera-tion reveals a significant difference between the displacement response time histories of the soil and underground structures compared to the displacement time histories of the input ground motion.(2)In the case of a two-story,three-span underground structure subjected to ground motion in the form of shear waves,the roof exhibits the highest peak acceleration and lateral displacement,followed by the middle plate,while the bottom plate shows the smallest values.Additionally,the inter-story displacement of the top layer is greater than that of the bottom layer.(3)Under earthquake loading,there are pronounced differences in the stress time history patterns across vari-ous regions of the underground structure.The stress peak at the joint between the bottom of the center column and the bottom plate is the highest observed.Furthermore,when ground motion input ceases,residual stresses remain in the structure.
万方数据
维普
