降雨入渗作用下土质斜坡稳定性的数值分析

Numerical Analysis of Soil Slope Stability Under Rainfall Infiltration

为分析研究降雨入渗作用下斜坡的稳定性,采用Phase2有限元软件,运用二维渗流数值模拟计算方法,建立能考虑渗流场对斜坡稳定性影响的数值模型,对降雨条件下的斜坡位移场、应力场和孔压场的变化情况进行分析。研究表明:降雨入渗会导致土质斜坡中土体孔隙水压力增加、基质吸力减小、土体的抗剪强度降低,影响了该斜坡的稳定性;随着降雨时间的增长,斜坡的安全系数会减小;当斜坡位移最大时,雨水继续下渗,表层坡体的基质吸力开始有所增加,下渗的水随着地下水饱和区流出,土体的含水量则相应的有所减小,容重也减小,土质斜坡稳定性又得到了延缓。

Finite element software Phase2 together with two-dimensional seepage numerical calculation method was used to build a numerical model in consideration of the influence of seepage field on slope stability. The displace- ment field, stress field and pore water pressure field were analyzed. The result indicated that rainfall infiltration re- sulted in the increase of pore water pressure in the soil, and decreases of matrix suction and shear strength. As rainfall duration increased, slope＇ s safety factor reduced. As slope displacement reached the maximum, matrix suction of the slope surface began through the groundwater saturation effect on slope stability. to increase due to the further infiltration of rain. And as the water draining zone, the water content and bulk density of soil decreased, which delayed the