Research on the Residual Soil Slope Stability Simulation under Rainfall Infiltration

Taking the fact that the Hang-Lan Highway is affected by the significant rainfall on the unsaturated residual soil slope and considering the effect of rainfall infiltration on unsaturated soil,this paper obtains the characteristic parameters of unsaturated permeability function by making the experimental research of hydraulic characteristic parameters of unsaturated soil and fitting soil-water characteristic curves with the high-accuracy Genuchten Van formula.On this basis,the analysis of unsaturated-saturated unstable seepage is combined with the finite element strength reduction method to make the coupling analysis of the seepage field and stress field of rainfall infiltration,simulate the transient seepage field caused by rain infiltration,and use the transient pore water pressure obtained from calculation to calculate the slope stability coefficient with the consideration of the influence of matrix suction.The paper also discusses the effect of rainfall intensity and rainfall duration on the distribution,development and stability of the slope seepage field of residual soil.