基于流固耦合动力模型的饱和土体-隧道体系地震反应研究

Seismic Response of Saturated Soil-tunnel System Based on Fluid-solid Coupling Dynamic Model

摘要:

基于ABAQUS软件平台，应用自行开发的流固耦合动力模型孔压单元模拟场地土体，并通过黏弹性人工边界方法实现地震动的输入，对饱和土体场地中的双孔隧道结构在地震荷载作用下的动力反应进行研究。计算结果表明：在地震反应结束时刻，场地土体位移幅值在两隧道之间以及两隧道的附近区域较大，而远离隧道的区域则较小；场地底部区域土体的孔压幅值较大，而场地顶部区域土体则较小；隧道左右两侧拱腰部位的衬砌的应力较大，而拱顶部位则较小。计算结果同时表明了流固耦合动力模型孔压单元在饱和土体-隧道体系地震反应研究中的适用性。

Abstract:

In this study, we used ABAQUS software to calculate the seismic response of a twin-bore tunnel in a saturated soil deposit. To simulate the saturated soil deposit, we employed a pore pressure element based on a fluid-solid coupling dynamic model for fluid-saturated porous media, and we input earthquake motion into the calculation model by a visco-elastic artificial boundary. Our numerical results show that at the end of the seismic response the displacement amplitudes of the soil between the two tunnels and near the tunnels is relatively large, while that far away from the tunnels is small. In addition, at the end of the seismic response, the pore pressure amplitude of the soil deposit at the bottom area of the site is relatively large, while that at the top is small. The stress of the tunnel lining at both tunnel arch waists is relatively large, while that in the tunnel vault is small. With respect to the study of the seismic response of tunnels in saturated soil deposits, we verified the applicability of the pore pressure element based on a fluid-solid coupling dynamic model for fluid-saturated porous media.