考虑前期降雨的非饱和土边坡稳定性分析

Stability Analysis of Unsaturated Soil Slope Considering Antecedent Precipitation

为研究降雨期和停雨期的非饱和土边坡稳定性变化,使用饱和-非饱和渗流理论,分析了考虑前期降雨的边坡的渗透系数及孔隙水压力变化,得到各阶段边坡安全系数。结果表明:在降雨过程中孔隙水压力和渗透系数随深度的增加呈先减小后增大的规律;坡脚受前期降雨的影响较明显;受渗透系数较小和临界滑动面较深的影响,停雨后边坡安全系数仍持续减小。

To study the stability of unsaturated soil slope during and after rainfall, with saturated-unsaturated seepage theory, the variation of the permeability coefficient and pore water pressure of slope, which took antecedent precipitation into consideration, was analyzed and the safety factor in each stage was obtained. The result shows that, during rainfall, the pore water pressure and permeability coefficient present regular change of decrease first then increase with the depth; the effect of antecedent precipitation on the slope toe is significant; due to small permeability coefficient and deep critical slip surface, the safety factor keeps decreasing yet after rainfall.