降雨入渗条件下边坡的稳定性分析

把降雨入渗条件下的边坡稳定性问题转化为图论中的最短路问题,基于饱和-非饱和渗流有限元计算得到的应力场和渗流场来计算边坡的最危险滑动面及其安全系数,在降雨入渗过程中,考虑基质吸力对滑动面抗剪强度的影响,采用修改的Mohr-Coulomb破坏准则来计算非饱和边坡的抗剪强度。降雨入渗过程及其对边坡力学行为的影响采用一个二维的有限元渗流-应力耦合程序进行分析,研究降雨入渗过程对边坡的孔隙水压力、位移以及安全系数的影响,计算结果表明,在降雨入渗过程中,边坡的安全系数在不断减小,降雨停止之后,边坡的安全系数还会持续减小一段时间,随着排水的不断进行,边坡的安全系数又会逐渐增大。

Stability analysis of slope under the condition of rainfall infiltration

The analysis on slope stability under rainfall infiltration condition is converted to solve the problem for searching the shortest path by Graph Theory.The dangerous slide surface and its safety factor are computed based on the stress field and infiltration field obtained by FEM analysis of saturated-unsaturated seepage flow problem.The influence of matric suction on shear strength of the slide surface in the process of rainfall infiltration are taken into account and the modified Mohr-Coulumb failure criterion is adopted to calculate the shear strength of unsaturated slope.The effect of rainfall infiltration on mechanical behaviors of slope including the pore water pressure,deformation and safety factor are analyzed by 2-D finite element seepage-stress coupled program.The computation result reflects the effect of rainfall infiltration and draining measures on slope stability.The result shows that the safety factor of the slope is gradually decreased in the process of rainfall infiltration and will continue to decrease for a short period after the stop of raining.It will resume gradually if the draining measure is keeping continue to work.