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.