基于随机地震动模型的盾构隧道非一致地震反应分析

NON-UNIFORM SEISMIC RESPONSE ANALYSIS OF SHIELD TUNNEL BASED ON RANDOM EARTHQUAKE GROUND MOTION MODEL

以常州地铁1号线为工程背景,建立了某一区间段双向盾构隧道的三维有限元计算模型。根据沿线Ⅲ类场地类别,基于随机地震动模型合成输入所需的多点随机地震动。计算双向盾构隧道在非一致随机地震动作用下的反应,与一致地震动激励的结果进行对比分析,得出该类场地条件下地震反应的一般特征。结果表明:非一致地震动激励增大了隧道的地震响应,沿隧道轴向方向各点地震反应存在差异,这种差异会影响轴向方向上的应力、应变,对隧道安全存在不可忽略的影响。

Based on the project of Changzhou Subway Line 1,a 3D finite element model of a two-way shield tunnel in a certain section was established. According to the class III site category along the route,the multi-point random earthquake ground motion for import was synthesized based on the random earthquake ground motion model. The response of the two-way shield tunnel under non-uniform stochastic earthquake ground motion was calculated,and the general characteristics of the seismic response under the same condition of the field were obtained by comparing with the results of the uniform earthquake ground motion. The results showed that the seismic response of the tunnel increased under the non-uniform seismic excitation. There are differences of the seismic response in the axial direction of tunnel,such differences will have impact on the axial stress and strain. It is important that the influence can not be ignored in the tunnel safety.