地铁隧道消防通道变截面处的地震影响分析

采用有限元分析软件MIDAS-GTS NX，以成都某地铁隧道为背景，对主隧道与消防通道连接的变截面处的地震反应特性进行数值模拟，分析在截面变化处，地下结构的地震响应。计算结果表明:在成都地铁场地人工地震波作用下，应力主要集中在上部混凝土板与垂直支撑柱的连接处；常遇地震时主要表现为结构的整体位移，自身变形较小；偶遇地震时变截面应力最大节点可能会有开裂现象；罕遇地震时地铁隧道围护由压应力转变为拉应力，应力值最大节点非常接近于混凝土的拉伸屈服，需要对相对位移较大的节点做加固措施。

Analysis on Seismic Response of Variable Cross-section Between Main Tunnel Andfire Engine Access

The seismic response characteristics of variable cross-section between main tunnel and fire engine access is numerically simulated by the finite element analysis software MIDAS GTS - NX to analysis the influence on the seismic response of variable cross-section of subsurface structure, background with a subway tunnel in Chengdu. The results show that under the effect of artificial seismic wave on the subway in Chengdu, the stress mainly concentrates on the joint of the upper concrete plate and the vertical support column. In the case of common earthquake, the main performance is the overall displacement of the structure, and the deformation is smaller. The maximum stress nodes of the cross section of an infrequent earthquake are likely to have a cracking phenomenon. When severe earthquake comes, the containment of subway tunnel turning from compressive stress to tensile stress, and the maximum stress value node is very close to the concrete tensile yield. Therefore, it is necessary to make reinforcement measures in the relatively large displacement node