地下水和地震共同作用下的边坡稳定性分析

基于边坡的有限元模型，研究了地下水位变化对边坡地震动力响应和稳定性的影响规律。通过有限元仿真分析发现：地下水的存在使土层含水率增大，坡脚位置为地下水渗出位置，在渗透力和孔隙水压力的影响下，有效应力降低，导致边坡抗剪强度减小。随着水深的增加，地下水对边坡坡脚的剪应力和剪应变影响逐渐增大，且远场地震作用时在不同水深下边坡坡脚的剪应力-剪应变值滞回延伸较大，说明远场地震作用对边坡坡脚抗震能力的影响较大。无地下水时，通过拟静力法计算的安全系数值位于动力安全系数值的中部偏下，且动力安全系数的最小值比拟静力法的静力安全系数小；而随着地下水位的上升，拟静力法计算的安全系数值开始移向动力安全系数值的中部偏上。因此，地下水位较高时，按照拟静力法计算的边坡安全系数进行边坡的稳定性评估将具有一定的潜在风险性。

Stability Analysis of Slope under the Interaction of Goundwater and Seismic Loads

Based on the finite element model of slope，the influence laws of the underground water level changes on seismic dynamic response and stability of the slope are studied.The analysis on the finite element simulation showed that the existence of groundwater makes the water content of soil increase，slope toe is the position of the groundwater seepage，and the effective stress is reduced under the influence of seepage force and pore water pressure which leads the shear strength to decrease.With the increase of the depth of the water，the influence of groundwater on shear stress and shear strain at the foot of slope increases gradually，and the shear stress and shear strain under far field earthquake in different water depth are greatly affected，showing that the influence of far field seismic on shear capacity at the foot of the slope is greater.The safety factor without the groundwater is located at the middle of the curve of dynamic safety factors，and the minimum value of the dynamic safety factor is greater than static safety factor.With the increase of underground water level，the safety factor calculated by pseudo-static method move to the upper of the dynamic safety factors.Thus，the safety factor calculated by the pseudo-static method to make the assessment of slope stability under the higher water level will have a certain potential risk