Hanyuan New County Secondary Roads On The 8th And Stability Of The Formation Mechanism Of Landslide

China is a landslide disaster-prone country. The southwest region is the main distribution area of landslide disasters in China. Landslide disasters in the southwest region has the features of large number, large scale, complex genetic mechanism and high hazardous which has become the hotspot and difficulty of researches in the field of geological disaster in China and the world. Accordingly, it is advantageous for China’s socialist modernization and the safety of our people’s lives and property if we study the landslide disasters in this region.Hanyuan is located in the beautiful scenery of the Dadu River, and also located in the convergence zone between the Sichuan Basin and the Tibetan Plateau. It belongs to the medium-sized mountain valley geomorphology which is very typical in the southwest region of China. This thesis is a study of the No.8Secondary Road landslide in the new county seat of Hanyuan. A great mass of area geology data had been collected adequately, and the engineering geological survey for the landslide area had been completed to identify the engineering geological conditions and basic characteristics of the landslide. Researches showed that it is a high-destructive medium-sized rock landslide which slides along the bedding planes and has obvious deformation characteristic. The thesis studied the genetic mechanism and deformation mechanism of the landslide in detail, and argued that the continuous rainfall and intense human engineering activities are the most important factors which caused the landslide. And the deformation mechanism of the landslide mainly shows as the traction-lapse type on overall sliding surface and the creep-tensional type on the secondary sliding surface.The thesis had used the Graphical Method and the Limit Equilibrium Analysis Methods to evaluate the stability of landslide conditions qualitatively and quantitatively. The result showed that the bedding planes are the controlling structural surface of the landslide; the secondary slip surface of the landslide is in the unstable status with a lowest stability factor in the heavy rain condition; the value of internal friction angle of rock and soil is the most sensitive factor which influencing the stability. Meanwhile, to analyze the No.8Secondary Road landslide in the new county seat of Hanyuan more scientifically, the thesis built the geo-mechanical model for the landslide, and used the finite element analysis software ANSYS to study the landslide with Numerical Simulation Method. The results show that the weathering interface of bedrock under the landslide area may be the most dangerous sliding surface. At last, the thesis proposed the recommendations of the prevention and control measures for the landslide disaster according to the analysis results.