Three-dimensional Stability Analysis Of Slope Considering Rainfall Infiltration

The evolution of landslides is closely related to rainfall,seismicity,topography,human activities and their geological structural conditions,among which in the south,short-term heavy rainfall is a very important inducement of landslides.the study area is affected by typhoon and rainstorm all the year round,and large-scale landslides are very easy to occur,so it is very necessary to study the slope stability under the condition of rainfall.This paper adopts the method of combining model test,numerical simulation and practical monitoring,the model test of slope is carried out considering confining pressure,the three-dimensional slope surface model is established by UAV tilt photography technology,the seepage field analysis and stability evaluation of three-dimensional slope are carried out by using ABAQUS,comparative analysis of numerical simulation analysis and the actual monitoring data of the slope,comprehensive evaluation of the stability of the slope.It provides a scientific basis for landslide prediction of similar projects in this area.The results show that:(1)in the model slope test,compared with the confining pressure,without confining pressure,the slope begins to destroy earlier and the range of failure is large,and the slope failure moves up the slope section by section from the foot of the slope.until it finally reaches a stable state.The failure of the model slope under confining pressure can be divided into three obvious stages: the first stage is the slip failure of the foot of the slope;the second stage is the small tensile failure above the foot of the slope;the third stage is the traction sliding failure of the whole middle of the slope.(2)The surface soil of the slope is most affected by rainfall,and the pore water pressure of the surface soil of the slope shows the characteristic of non-linear distribution and linear distribution after a certain depth,The time of the pore water pressure response is positively correlated with the distance from the slope,and the response time of the saturation is negatively correlated with the distance from the slope.The pore water pressure is closely related to the change of the change over time and the type of rainfall.(3)in the initial stage of rainfall,the rainfall infiltration is mainly vertical slope infiltration,and in the later stage of rainfall,vertical infiltration is the main infiltration.After the rain stopped,the pore water in the surface soil infiltrated to the foot of the slope parallel to the direction of the slope on the one hand,and continuously infiltrated into the deep part of the slope under the action of gravity on the other hand.(4)through the analysis of the proposed calculation model,it is concluded that the landslide area is ellipsoidal in space,and the slip surface is an arc-shaped slip surface from the top of the slope to the foot of the slope,and the cumulative displacement of the surface has gone through three stages.that is,slow deformation stage,accelerated deformation stage and stable deformation stage.the simulation results are consistent with the field failure and monitoring results.By comparing the field monitoring data with the numerical model established in this paper,it is verified that a series of technical methods proposed are feasible,and the real-time monitoring of engineering slope is realized by this method.it provides a theoretical basis for the further monitoring and treatment of the project,and provides a meaningful reference for the monitoring and prediction of highway slope in this area in the future.