Stability Analysis of Slope with Weak Interbedded Granite Residual Soil Under Rainfall Conditions

YU Wei; CHEN Gang; LIAO Kewu; HUANG Haijiang

doi:10.13512/j.hndz.2024.04.16

Abstract：In order to study the stability of slopes with weak interlayer under rainfall infiltration effect and reduce the occurrence of landslide disasters,an actual slope project was taken as an example,and the finite difference software was used to establish a three-dimensional slope numerical model.The pore water pressure,displacement field,plastic zone,velocity field,and the maximum shear strain increment field of the slopes with weaker interlayer were analyzed,and the influence of the thickness of weak interlayer on slope stability was studied.The results show that continuous rainfall makes a through and continuous shear plastic zone appear at the weak interlayer.At the same time,the shear plastic zone expands with the increase in rainfall time.With the increase in rainfall time,the displacement,pore water pressure,the maximum shear strain increment,and the slip velocity of the weak interlayer increase,and the ratio of stress to strength decreases.The prolonged rainfall makes the slopes with weak interlayer slip along the potential slip surface of the weak interlayer.The destabilizing deformation of the slopes is mainly caused by the change of the weak interlayer,and the deformation is intensified with the increase in rainfall time.The existence of the weak interlayer affects the pore water pressure at the interface between the upper and lower weak interlayer,and the pore water pressure gradually increases from the slope towards the direction of the weak interlayer.The increase in rainfall time and the existence of the weak interlayer both reduce the stability of the slopes.When the rainfall conditions are the same,the safety factor of the slopes decreases with the increase in the thickness of the weak interlayer.