3D refined nonlinear analysis of seismic response characteristics of frame metro station under near-field strong ground motion of large earthquake

Based on the explicit finite method of ABAQUS software and the 32CPU parallel computing cluster platform, a three-dimensional refined finite element model for deep soft soil-frame metro station structure is established to study its nonlinear seismic responses to Qingping and Wolong ground motions recorded during Wenchuang Earthquake and Nanjing artificial waves with the exceedance probability of 3% within 100 years. The results show that the underground frame metro station structure in deep soft site may be seriously damaged under near-field strong ground motion, and even plastic failure or collapse may appear. Moreover, the combining sites of pillars, floor slabs and side walls are in unfavorable positions in seismic resistance, while the pillars are the weakest components. In addition, the peak acceleration and the spectrum characteristics of the input near-field ground motions also have great influences on the earthquake response of the underground structure. The seismic response of the subway station structure has a noticeable three-dimensional effect. Furthermore, the structure will generate permanent displacements to be accumulated to one side under the near-field ground motion of large earthquake. The structural responses under Qingping and Wolong ground motions are obviously larger than those under Nanjing artificial waves. Besides, the seismic damage of shallowly buried parts is more than that of the deep ones.