地震和降雨条件下黄土高填方边坡稳定性分析

针对地震和降雨会影响黄土高填方边坡稳定性的问题,采用地震动力计算、完全流固耦合计算和强度折减计算,对正在使用的黄土高填方边坡进行分析,并对边坡土体位移时程、加速度功率频谱、吸力、有效应力和最小安全性系数进行分析,研究地震和降雨入渗条件对正在使用的黄土高填方边坡稳定性的影响.结果表明:地震作用对黄土高填方边坡表层土体作用大于填方基底土体作用;降雨入渗对边坡土体的影响范围为表层土体和浅层土体;降雨入渗使得边坡表层土体的吸力和有效应力减小,而使浅层土体局部吸力增大;降雨过程中边坡表层土体有效应力减小,浅层土体有效应力先增加后逐渐减小;地震后降雨入渗引起边坡最危险滑移面区域发生改变,降雨速率和降雨持续时间均对最小安全性系数有影响,降雨结束后边坡最小安全性系数降低.该研究为三维条件下地震和降雨入渗对正在使用的黄土高填方边坡稳定性研究提供参考.

Stability analysis of high fill slope with loess under earthquake and rainfall infiltration

In order to investigate the effect of earthquake and rainfall infiltration on the stability of loess high fill subgrade slope, a dynamic seismic calculation, complete fluid-solid coupling calculation and strength reduction calculation are used to analyze and compare the loess high fill slope in use. The displacement time history, acceleration power spectrum, suction, effective stress and minimum safety factor of slope soil are used to study the effect of earthquake and rainfall infiltration conditions on the stability of loess high fill slopes. The results show that the effect of earthquake on the surface soil of loess high fill slope is greater than that on the base soil. The influence range of rainfall infiltration on the slope soil is surface soil and shallow soil. Rainfall infiltration reduces the suction and effective stress of the surface soil of the slope, while the local suction of the shallow soil is increased. In the process of rainfall, the effective stress of slope surface soil is decreased, the effective stress of the shallow soil is increased first and then decreases gradually. After the earthquake, the infiltration of the slope causes the change of the most dangerous slip surface area of the slope, the rainfall rate and rainfall duration have an impact on the minimum safety factor, and the minimum safety factor of the slope is decreased after the rainfall. This study provides a reference for the study of the stability of loess high-filled slope under 3D conditions of earthquakes and rainfall infiltration.