Stability Analysis And Numerical Simulation Of Dongchizhuang Landslide In Pingshan County

Landslides are one of the three natural disasters.Their wide distribution,high frequency,and destructive characteristics have had a huge impact on the development of my country's national economy.With the continuous increase of human production and life needs and the continuous increase of engineering activities,the original balance of the ecological environment has been broken,and landslide disasters are increasing day by day.In order to strengthen the prevention and control of earth disasters,to avoid and reduce the threats to people's lives and properties caused by geological disasters,It is essential to study the stability analysis and disaster prevention of landslides.This paper takes the Dongchizhuang landslide in Pingshan County as the research object,introduces the general situation of the geological environment of the landslide area,finds out the characteristics of the landslide through field investigation and engineering geological means,and analyzes the formation mechanism,influencing factors and movement effects of the Dongchizhuang landslide.Destruction mode.On this basis,the transfer coefficient method and numerical simulation are used to conduct in-depth research on the stability of the Dongchizhuang landslide,and a targeted and reasonable prevention plan design is made.The main research results are as follows:(1)The Dongchizhuang landslide is mainly affected by the development of surface water bodies,and a large amount of farmland and fish ponds are formed under the influence of water infiltration.At present,the landslide is in the creeping stage.Under the continuous action of rainfall and surface water,the front edge of the landslide first appears to be slippery,and then the trailing edge is torn apart,the creep deformation characteristics are aggravated,and a complete sliding surface is gradually formed.(2)Using the transfer coefficient method to calculate the stability of the profile under various working conditions,it is concluded that the overall landslide is in a stable state under natural conditions;under heavy rainfall conditions,a large area of the slope is in an unstable state,and it is easy to cut out the surface and secondary Shear failure occurs on the cut-out surface,resulting in a landslide disaster;under the external seismic load,the slope is basically stable as a whole,but the soil is prone to slippage along the front edge of the 3-3'section.The calculation results are consistent with the actual situation..(3)Using FLAC3D for numerical simulation,using the strength reduction method to obtain the model's stability coefficient under natural conditions of 1.15,which is in a stable state,and under heavy rain conditions,the stability coefficient of which is 1.12,which is in an unstable state,the simulation results Consistent with the above calculation results.On this basis,the obtained stress-strain characteristic map combined with the analysis of the shear strain increment map shows that the Dongchizhuang landslide has potential shear zones at the base-cover interface.Under adverse conditions,the penetration of the shear zone will cause the upper sliding body.Sliding,forming a disaster.(4)Using the PFC2D software to simulate the movement with 3-3' as a typical section,it is concluded that the deformation and failure of the toe of the front slope occur first at the beginning of the landslide,and the damage characteristics gradually increase with time,and it shows the development of traction towards the rear edge.Trend,the failure mode is a towed soil landslide,and the simulation results are consistent with the actual situation.(5)Using the foregoing calculation results and simulation results,it is determined to select the self-weight + heavy rain conditions to design the landslide treatment plan.The prevention measures are "anti-slide pile + retaining wall + protective embankment +intercepting drainage ditch + layout monitoring point".