库区边坡地震-渗流耦合数值模拟

Numerical simulation of seismic and seepage coupling of slope in reservoir area

为系统研究库区边坡在地震-渗流应力作用下的边坡应力,渗流特性及稳定性的变化规律,对库区边坡地震动力响应进行了有限元研究,数值结果表明:地震作用下堤坝内部浸润线具有一定变化,主要升高部位在于中密砂内部,而在黏质砂部位浸润线的变化幅度则不大;堤坝内部中密砂上部及中部的有效应力变化剧烈,下部变化幅度较小,且临近上游侧的上部地震过程中发生液化失稳;上下游坝坡在地震过程中均出现小于1的情况,上游坝坡最小安全系数为0.82,下游坝坡最小安全系数为0.91,表明地震过程中上游坝坡更容易失稳。

In order to systematically study the variation of slope stress,seepage characteristics and stability under earthquake-seepage stress,the seismic dynamic response of slope in reservoir area is studied by finite element method.The numerical results show that the infiltration line in the embankment under earthquake action has a certain change,and the main rising part lies in the middle dense sand,but the change range of the infiltration line in the viscous sand is not large.The effective stress in the upper and middle part of the dense sand in the dike changes violently,the variation range in the lower part is small,and liquefaction instability occurs in the upper part near the upstream side,and the upstream and downstream dam slopes are less than 1 in the process of earthquake,and the upstream dam slope is less than 1 in the process of earthquake.The minimum safety factor is 0.82 and the minimum safety factor of downstream dam slope is 0.91,which indicates that the upstream dam slope is more prone to instability during earthquake.