埋深对地铁车站地震反应的影响分析

关于埋深对地下结构地震反应的影响的研究对象多见于地下隧道，对地铁车站地震反应受埋深影响变化规律缺乏深入研究。本文基于ANSYS有限元软件，采用改进的简化方法建立三种不同埋深的地铁车站结构有限元模型，以两种基岩波的水平向和竖向地震动作为激励，求解各模型中地铁车站结构重要部位的地震反应。分析不同埋深时地铁车站结构惯性作用、侧面土体和上部土体三个因素对地铁车站地震反应的影响情况。分析结果表明:在双向地震作用下，地铁车站侧壁弯矩、剪力、轴力和中柱轴力随埋深的增加而增加，中柱剪力和弯矩随埋深增加而减少。埋深越深，侧面土体对地铁车站地震反应影响越大；上部土体使中柱轴力不断增加；结构自身的惯性作用对其地震反应的贡献逐渐减小。

Influence of buried depth on seismic response of subway station

The research objects about the influence of buried depth on the seismic response of underground structures are mostly found in underground tunnels,and there is a lack of in-depth study on the variation law of seismic response of subway stations affected by buried depth. In this paper,based on ANSYS finite element software,three finite element models of subway station structure with different depths are established by improved simplified method. The horizontal and vertical ground motions of two bedrock waves are used as excitations to solve the seismic response of important parts of subway station structure in each model. The influence of the three factors of the inertia of the subway station structure,the side soil and the upper soil on the seismic response of the subway station is analyzed. The analysis results show that under bidirectional earthquake,the bending moment,shear force,axial force and axial force of the middle column of the subway station increase with the increase of buried depth,and the shear force and bending moment of the middle column decrease with the increase of buried depth. The deeper the buried depth,the greater the influence of side soil on the seismic response of subway station;the upper soil increases the axial force of the middle column;the contribution of the inertia of the structure to its seismic response gradually decreases.