Study On Dynamic Response Characteristics Of Rock Slope Based On Discrete Element Method

China is an earthquake prone country.With the increasing investment in the western region,a large number of rock slopes are widely distributed in the process of water conservancy project construction.Part of Southwest China is located in the earthquake prone zone.Under the action of earthquake load,the rock slope will be greatly affected.Slope problem has always been a hot topic for scholars.Generally speaking,the dynamic response of slope determines its failure characteristics.Therefore,it is very important to understand the dynamic response of slope under strong earthquake.Based on the in-depth summary of the research status of slope dynamic problems,this paper studies the dynamic response characteristics of deformable body slope through theoretical methods,numerical simulation and practical engineering cases(1)The equation of seismic wave is derived briefly,and the dynamic response of seismic wave passing through structural plane and the amplitude distribution of P-wave passing through structural plane are discussed.(2)The numerical calculation model of landslide is established in PFC2 D,and the dynamic response law and deformation and failure process of slope are numerically simulated by inputting Wolong seismic wave.The test results show that the horizontal acceleration of argillaceous limestone and leopard skin dolomitic limestone in slope is significantly amplified under the action of earthquake,Compared with the input wave,the velocity time history curve will be distorted obviously;The amplification effect of dolomitic limestone on horizontal acceleration is not obvious,and the velocity time history curve has no obvious distortion compared with the input wave.In the whole earthquake process,due to the amplification effect of acceleration,the deformation trend of argillaceous limestone in the upper part of the slope is larger,which will squeeze leopard skin dolomitic limestone in the lower part,resulting in gradual stress concentration and slow shear deformation in the lower part of the rock mass.At the same time,because the shear deformation of the lower part of the rock mass provides space for the deformation of the upper part of the rock mass,the upper part of the rock mass has a strong sliding deformation,In the end,the displacement in the slope changes abruptly.The rock mass of argillaceous limestone and leopard skin dolomitic limestone in the slope is unstable due to the upper sliding deformation and the lower shear deformation.The deformation and failure process of the deformation body in front of the pit under earthquake can be divided into: Seismic crack of the slope,collapse of the slope toe and shear slip.(3)In view of the complex dynamic characteristics of Woqian landslide,this paper analyzes the Woqian landslide based on 3DEC discrete element software,and the movement characteristics of the model are in good agreement with the actual geological conditions.From the upper part to the lower part,the movement direction and movement mode are changed.Through three-dimensional discrete element numerical calculation,the whole movement process of the landslide body in front of the pit can be divided into four stages: "ejection start → overall collapse → rapid sliding →vibration accumulation";The displacement response law is reflected in the whole movement process of slope collapse,which shows complex motion characteristics such as ejection,steering,collision and reverse;The law of velocity response shows that the collapse body continuously vibrates and accelerates after starting,and the velocity drops precipically after violent impact until it is stable.