基于流固耦合两相介质动力模型的水下隧道结构地震反应研究

Seismic Response of Underwater Tunnels Based on The Fluid-solid Coupling Dynamic Model of Fluid-saturated Porous Media

基于ABAQUS有限元软件平台,应用流固耦合两相介质动力模型孔压单元模拟场地饱和土体,进行了水下饱和土体场地上隧道结构地震反应的计算研究.计算结果表明:对于饱和土体场地上的单洞隧道,在地震动输入结束后,隧道底部附近区域土体的孔隙水压力值最大,此时隧道两侧土体的孔隙水压力呈现对称分布;对于饱和土体场地上的双洞隧道,在地震动输入结束后,两隧道之间区域土体的孔压为正值,而隧道下方区域土体的孔压为负值;左右两侧隧道的应力呈对称分布.计算工作同时表明了流固耦合两相介质动力模型孔压单元在饱和土体—地下结构体系地震反应研究中的有效性.

The seismic response of underwater tunnels in the saturated soil is studied by ABAQUS,with the site soil simulated by the pore pressure element deduced from fluid-solid coupling dynamic model of fluid-saturated porous media. Calculated results illustrate that to the singlehole tunnel in the saturated soil,the pore pressure of the soil near the bottom of tunnel is maximal by the end of the input earthquake wave. At that moment the value of the pore pressure of the soil located in two sides of tunnel is equal. On the other hand,to the double-hole tunnel in the saturated soil,the value of the pore pressure of the soil between two tunnels is positive,while the value of the pore pressure of the soil below the tunnels is negative. The value of the stress of two tunnels is equal. In the meanwhile,it is shown that the pore pressure element deduced from fluid-solid coupling dynamic model of fluid-saturated porous media is effective to the study of the seismic response of the underground structures in the saturated soil.