Formation Mechanism And Stability Analysis Of Landslide Group In Shikanchang Town

In the past ten years,earthquakes occurred frequently in the southwest of China,resulting in tens of thousands of landslides,causing huge losses to the people.It is of great significance to summarize the instability mode of the landslides under earthquake conditions and to analyze the stability of the earthquake landslides.Therefore,this paper takes the Wenchuan earthquake induced landslide group as the research object.On the basis of fully mastering the engineering geological conditions in the study area,the field investigation,laboratory experiment,theoretical calculation and numerical simulation are used to make a comprehensive study of the various disaster bodies in the landslide group.The main contents and conclusions are as follows:(1)The landslide group in the Shi Kan Chang town is a large group of landslides caused by the Wenchuan earthquake.The landslide group is composed of three landslides.The slide bodies are distributed in a close proximity to the plane.From north to south,the landslides are 1#,2#and 3#landslides.Among them,the 1#landslide is in the surface of the tongue,the main sliding direction is 327 degrees,and the volume of the slide body is the volume of the slide.1.23 x 10~6m~3,belonging to the deep and large rock landslides,the 2#landslide is elliptical in the plane,the main sliding direction is 329 degrees and the volume is about 3.20x 10~4m~3,which belongs to the shallow and small loose layer landslide.The 3#landslide is elliptical in the plane,the main sliding direction is 335 degrees and the volume is about 1.80x 10~5m~3,which belongs to the middle middle type loose layer landslide.(2)According to the summing up of the law of the development of Seismic Landslides by the predecessors,this paper systematically analyzes the various factors that cause mass collapse and failure of the slope.After analysis,it is believed that the formation of the landslide group in the stone camp is controlled by a variety of factors,of which three are faced with the characteristics of the empty terrain,and the sloping structure with a loose upper part and a complete lower part is the original slope.The main internal cause of large-scale landslide failure is the strike slip thrust movement of the fault in the earthquake,which is the direct internal force to trigger the landslide.(3)The stability of the 3 landslide deposits is calculated by the transfer coefficient method.The results show that the stability of 1#landslide is good under the natural and rainfall conditions,but the stability is poor under the earthquake condition,and the stability of the 2#and 3#landslides is better under the three conditions.(4)Using the GID software,the digital elevation model(DEM model)is established for the large scale 1#landslide,and the deformation characteristics and stability under the natural,rainfall and earthquake conditions are analyzed by Flac3D software,and the conclusion is in agreement with the calculation results of the unbalanced thrust method.(5)According to the analysis of the stability of the landslide group above,the control measures of the anti slide pile supporting project and the drainage project are put forward to the large 1#landslide,and the deformation of the rear sliding body is selected as the evaluation criterion,and the effectiveness of the support measures is verified by the Flac3D software.In the same time,the 2#and the 3#landslides with smaller development scale are raised.To strengthen monitoring and reduce the control scheme of disturbance.