交叉隧道在不同夹层土体厚度下的地震响应分析

Dynamic Response Analysis of Intersecting Tunnel Structure under Different Interlayer Soil Thickness

基于FLAC3D软件,采用数值模拟的方法,对在不同夹层土体厚度及不同峰值加速度情况下,交叉隧道的地震动力响应进行研究,得出了交叉隧道结构的地震动力响应规律。结果表明:上层隧道的相对水平位移差明显大于下层隧道的相对水平位移差。上层隧道地震应力反应大于下层隧道的地震应力反应。随着夹层土体厚度的增大,衬砌结构的加速度、位移和应力略有变化但总体变化不大,并得出0.5 D～2 D(D为隧道外径)的厚度为较理想的夹层土体厚度,此时加速度、位移和应力总体较其它偏于安全。此结论为穿越既有隧道的交叉隧道工程选线和穿越深度提供重要的理论参考依据。

Based on the FLAC3D, with numerical simulation method, analysis intersecting tunnels structure under different soil thickness dynamic responses and different peak accelerations, we obtained dynamic response rules of intersecting tunnels. The results showed that, the upper tunnel relative horizontal displacement difference is significantly greater than the lower tunnel relative horizontal displacement difference. With the increasing of interlayer soil thickness, the acceleration, displacement and stress of structure change slightly, but overall less variation. And O. 5 D -2 D （D represents tunnel outside diameter） thickness is ideal soil thickness, the acceleration, displacement and stress are safer than others. This conclusion provides an important theoretical reference for crossing existing tunnel engineering with selecting route and the depth.