Formation Mechanism And Stability Analysis Of Nanshan Landslide In Kaixian County,

China has a vast territory, complicated geomorphology and topography. According to an authority statistics that85%of the land area is mountainous. Each year a huge number of casualties and economic losses are caused by landslides, and all of this made China be one of the most serious disaster countries. Landslides which controlled by rock layers, particularly in the western area of China, often interrupted traffic, destroy buildings, blocked rivers, and buried village due to their large scale and hazardous. Because of the characteristics of landslides, such as the diversified and complicated formation mechanism, influencing factors, and difficulty prediction, landslides are always concerted by researchers as one of the most important geological environmental problem.Kaixian Nansan landslide which is located in the upstream area of Sanxia reservoir is acted as the object of study in this article. Based on the collection of local geological structure, topography, hydro-geological material, and with the means of drilling, pitting, laboratory experiment, the study investigated the characteristics of gliding mass, sliding zone and sliding, and obtained that this landslide is a typical large-scale layered rock landslide by the evidence that a group of dominant structural surface is developed in it, and the tendency of layered rocks is similar with the slope one. Then the paper thorough analysed the formation mechanism, influence factors and definite weighting factors of the layer landslide, defined that rainfall and the cut of slope toe are the dominant inducement, toe buckling traction and the top of slope’s split impulse are the main movement formation. Depended on the above researches, stereographic projection is used to judge the landslide’s stability, limited equilibrium method and FLAC3D numerical simulated analysis are employed to evaluate the present stability and developing trends in this paper. Furthermore, the study is used linear method to evaluate the sensitivity factor which affect the landslide stability, obtain a conclusion, that the angle of internal friction φ is the dominant factor which will influence the stability of landslide, which will provide a reference and basis for the prevention and cure of such similar landslides.