| China is a country with many mountainous areas,and rainfall leads to slope instability,which in turn causes natural disasters such as landslides and debris flows to occur frequently,resulting in huge casualties and economic losses.Therefore,the study of slope stability under rainfall conditions has important engineering significance.This paper uses finite element software to analyse the softening process of slopes,the influence of slope top loading and soilwater coupling on the stability of soil slopes,and the effect of anti-slip pile reinforced slopes under rainfall conditions based on the strength reduction method.The main research of this paper is as follows:(1)Based on the strain softening theory,the secondary development of ABAQUS finite element software is used to analyse the effect of softening effect of soil shear strength on soil slope stability.The study shows that: the smaller the peak plastic strain,the greater the kinetic energy generated by the instability,the further the displacement of the landslide after instability,the greater the total strain energy;at the same moment,the wider the plastic zone generated by the slip zone,and the more obvious the deformation of the shear zone with the extension of time.The smaller the residual internal friction angle,the greater the slip distance and the easier it is to produce cracks at the top of the slope,the greater the kinetic energy generated by the instability,and the greater the total strain energy generated by the instability;at the same time,the wider the plastic zone generated by the slip zone,the more obvious the deformation of the shear zone of the landslide as time increases.The smaller the residual cohesion,the greater the slip distance of the soil at the top of the slope,the greater the kinetic energy generated by the instability,and the greater the total strain energy generated by the instability;the wider the plastic zone generated by the slip zone of the soil slope with the extension of time.(2)The intensity reduction method was used to simulate the stability of slopes under rainfall conditions.The coefficient of safety of the soil slope under different rainfall intensities,different rainfall durations,different slope top loads and different rainfall patterns,as well as the changes in the saturation and pore water pressure at the characteristic points,were analysed.The results show that with the increase of the total amount of rainwater infiltration in the soil,the pore water pressure and saturation at the characteristic points of the soil slope increase continuously when the slope is not loaded,but the safety coefficient of the slope gradually decreases;after a certain load is applied to the top of the slope,the pore water pressure and saturation at the characteristic points of the soil slope are the same as when the slope is not loaded,but the safety coefficient of the slope further decreases.When the rainfall duration and intensity remain unchanged,the pore water pressure and saturation at the characteristic points remain unchanged as the load on the top of the slope increases,but the slope safety factor further decreases.(3)Based on the pile-soil coupled finite element model,the effect of anti-slip piles on slope reinforcement under rainfall conditions is analysed.The study shows that rainfall will increase the weight of the soil slope,making the sliding force of the soil increase and the shear strength decrease,so it is necessary to combine various factors to optimize the design of antislip piles.Through the analysis of the pile position,the anti-slip pile is close to the foot or top of the slope,when the slope is unstable,the soil will slide out from the top or foot of the slope respectively,so the anti-slip pile is more effective when it is located in the middle of the slope;through the analysis of the pile diameter,the anti-slip pile diameter is too small,the slope instability will cause the anti-slip pile to break,which will not play the anti-slip effect;through the analysis of the pile length,when the anti-slip pile is embedded in the rock layer is short,it will lose the anti-slip effect;when When the anti-slip pile is embedded in a long rock layer,it will cause a waste of material. |
