强震作用下密贴交叉组合地铁车站三维地震动响应分析

3D dynamic response analysis of the closely-attached intersecting underground subway under strong earthquake

基于FLAC3D有限差分软件,建立密贴交叉组合地铁地下车站结构的三维计算模型,研究强震作用下密贴交叉组合地铁地下车站结构的三维非线性地震反应特性,并与单一浅埋/深埋地铁地下车站结构的地震反应特性进行比较。研究结果表明:密贴交叉组合车站结构中,由于上下层车站相互作用影响,对上下层车站的相对水平位移均具有放大作用;上层车站的加速度放大系数小于浅埋车站,而下层车站的加速度放大系数略比深埋车站的大,且变化率较大的部位均发生在密贴交叉部位;下层车站的存在,对上层车站结构的应力有一定的消弱作用,但是由于两车站结构相互作用影响,在两车站交叉部位出现应力集中,致使交叉部位应力出现明显的放大效应。

According to the finite difference procedure FLAC3D, a three -dimensional computational model for closely - attached intersecting subway structure was established and used to research on the 3D nonlinear seismic response of the closely - attached intersecting subway structure under strong earthquake and to compare with the seismic response of single shallow/deep subway structure. The results show that in the closely -attached inter- slightly larger than on the the deep buried station, and the bigger change rate of acceleration amplification always occurs on the cross site on the cross part. The existence of lower station can weaken the stress of upper station to some extent. However, clue to the interaction effect of two station structure, stress concentration occurs in the cross part and leads to significant amplification effect of stress generated on the cross site.