The three-dimensional(3D) equivalent viscoelastic boundary element is introduced based on the theory of viscoelastic artificial boundary. The wave input method of wave scattering problems in free field is stated and used in 3D layered half space. The seismic waves can be transformed into equivalent forces adding on the artificial boundary nodes. The equivalent forces are calculated by finite element model with lumped mass and finite difference method. A 3D finite element model of soil-structure interaction system is built in the platform of ABAQUS software. Seismic responses of subway station structure are analyzed including factors that influence it. The open system is turned to a closed-system by adding local artificial boundary. The modal characteristics of the soil and station are obtained by modal analysis. The seismic responses of the subway station structure in horizontal and vertical directions are analyzed under SV and P waves. The corresponding regulations and distribution of internal force are studied to examine the most vulnerable positions. The results show that the SV waves inputted in transverse direction is the worst case to the subway station. The forces of the members suddenly changes in position at where the stiffness of the structure is changed greatly. The P waves have greatly effect on the axial force of the structure.%引入三维等效黏弹性边界单元，阐述波动散射问题的自由波场输入方法，推广应用于三维水平成层半空间模型，采用集中有限元质量模型和有限差分的概念将地震动场转化为施加在人工边界节点上的等效荷载。基于某大型地铁车站，利用大型通用有限元ABAQUS软件建立考虑土-结构动力相互作用的三维有限元整体计算模型，通过局部人工边界的施加，实现了开放系统向封闭系统的转换，对土-地铁车站结构动力相互作用的整体三维模型进行模态分析，得到车站以及地基的振型特征。分析地铁车站结构在SV波及P波地震波作用下的反应，得到相应的内力分布规律和结构不利位置。从分析结果可以看出，地震波横向 SV 波输入时对车站结构最不利，结构刚度突变位置的构件内力也存在突变，而P波对结构的轴力影响较大。
展开▼
