Abstract: In order to analyze the stability of a landslide in Wanyuan City in Sichuan Province,through field engineering survey,geological mapping,drilling,in-situ monitoring and sample collection and testing,the deformation characteristics of the landslide is discussed,engineering geological model of the landslide is established,and the qualitative and quantitative stability analysis of the landslide is conducted.The stability coefficients of the four potential sliding surfaces of the main section under the conditions of natural and heavy rains are calculated respectively by adopting unbalanced transfer coefficient method.The comprehensive study results show that under the natural condition,the landslide is in the state of stable~basically stable,the actuality stability of the landslide is good,while under the condition of heavy rains,the landslide is in the state of stable~unstable,the actuality stability of the landslide is poorer.It is further indicated that with the depth of the potential sliding surfaces under the two condition,the stability of the landslide are both increased,the more depth,the less likely of sliding.Based on the above analysis results of this paper,the two specific prevention and treatment schemes are proposed.The related analysis results can provide some reference for the prevention and treatment of the landslide.

Key words: Field deformation monitoring, Man section, Engineering geological model, Stability coefficient, Prevention and treatment