软土矩形地铁隧道地震反应特性分析

为研究在不同类型的软土地层条件下地铁隧道的地震反应特性,本文选用El-Centro波作为隧道基岩处水平输入的地震波,利用大型有限元软件ANSYS分析上海矩形地铁隧道在三种典型场地中的地震反应特性,获得了矩形隧道在三种场地中的地震反应规律,结果表明:处于软土地层中的矩形地铁隧道,应力的抗震薄弱位置在衬砌形状突变处,水平位移的抗震薄弱位置在隧道顶部,水平加速度的抗震薄弱位置在隧道底部,设计时应加强薄弱部位的抗震设防,这为矩形地铁隧道抗震设计提供了参考依据。

Analysis on seismic response characteristics of rectangular subway tunnels in soft soil

In order to research the seismic response characteristics of subway tunnels in different types of soft soil stratum,El-Centro wave is selected as the horizontal input seismic wave at the bedrock of the tunnel.The seismic response characteristics of Shanghai rectangular subway tunnel in three typical sites are analyzed by ANSYS and the seismic response laws of rectangular tunnel are obtained.The result shows that for the rectangular subway tunnel in soft stratum,the weakest position of the stress is at the sudden change of the lining shape,the weakest position of the horizontal displacement is at the top of the tunnel,and the weakest position of the horizontal acceleration is at the bottom of the tunnel.Therefore,weak parts should be strengthened in design and which provides a reference for the anti-seismic design of rectangular subway tunnel.