水库堤坝渗流-动力稳定性分析

Stability Analysis of Seepage and Dynamic Coupling of Reservoir Embankment

针对渗流-动力耦合下的堤坝渗流特性及稳定性研究不足的问题,以某堤坝工程为例,利用Geostudio软件中的SEEP/W、SLOPE/W、QUAKE/W三个模块进行渗流-动力耦合计算,对堤坝在地震作用下的不同测点超孔隙水压力、有效应力、位移、动力安全系数及永久位移进行了数值模拟。结果表明,地震作用下堤坝内部浸润线发生变化,变化高差为0.2m,其主要升高部位位于中密砂内部,粘质砂部位浸润线的变幅不大;堤坝内部中密砂上部及中部的有效应力变化剧烈,下部变幅较小,且临近上游侧的上部地震过程中堤坝有效应力降低为0,发生液化失稳;上下游坝坡安全系数在地震过程中均出现小于1的情况,最小安全系数分别为0.82、0.91,可见地震过程中上游坝坡更容易失稳。

In view of the lack of previous research on seepage characteristics and stability of dike under seepage-dynamic coupling,taking a dike project as research object,the seepage-dynamic coupling calculation is carried out by using three modules of SEEP/W,SLOPE/W and QUAKE/W in Geostudio software.The excess pore water pressure,effective stress,displacement,dynamic safety factor and permanent displacement of embankment at different measuring points under earthquake action are simulated.The results show that the infiltration line changes under earthquake,and the variation height difference is 0.2 m.The main rising position is in the middle dense sand.The effective stress in the upper and middle part of the dense sand changes violently,and the variation range in the lower part is small,and the effective stress of the dam decreases to 0 during the earthquake near the upstream side,resulting in liquefaction instability.The safety factors of the upstream and downstream dam slopes are less than 1 in the process of earthquake,the minimum safety factor of upstream and downstream dam slope are respectively 0.82 and 0.91,which indicates that the upstream dam slope is more prone to instability during earthquake.