Stability Analysis Of No. Ⅲ Lanslide In Xishan, Xihe County

With the rapid development of domestic economy and the growth of urbanpopulation, the influence of landslide on people’ lives are getting more and moreserious; therefore, to make a deep analysis on landslide becomes increasinglyimportant. This paper especially take Xishan No.Ⅲ landslide which is in Xihe countyas an example: Based on field investigation and collected data, we made an analysison the factors that affect the stability of the landslide; We adopted four modules,SLOPE/W、 SEPP/W、SIGMA/W and QUAKE/W in Geostudio software to simulatethe landslide under four different conditions, i.e. nature, rainfall, earthquake andcoupling effect of earthquake and rainfall, then analyze the stability. This will not onlyprovide a technical support to landslide control, but also can get new research resultsin the field which scholars make less study of.The main results are showed as follows:1. The geography and the lithology of the landslide offered extremely favorableconditions for sliding, the specific terrain is the dominant factor of thelandslide formation, the earthquake and the rainfall are the main predisposingfactors for sliding.2. Analyze the stability of No. Ⅲ landslide under four different conditions:⑴We adopted SLOPE/W module to analyze the stability under naturecondition, which is based on Morgenstern-Price method. The results showthat this landslide is stable.⑵SEEP/W module was adopted to analyze unstable seepage field in thelandslide under different rainfall conditions, then we adopted SLOPE/Wmodule to analyze the stability. As the results show: under the same rainfallamount, the smaller the rainfall intensity, the more infiltration.⑶We used dynamic finite element to simulate the landslide underearthquake condition that the peak acceleration is0.3g by employingQUAKE/W module, which is based on dynamic time-history analysis. It wasfound that the landslide will slide about0.18m, and will be in unstable status. ⑷In order to analyze the stability of the landslide under coupling effect ofearthquake and rainfall, QUAKE/W module coupled with SEEP/W results wasemployed, and then we used SLOPE/W to analyze the stability. The results showthat: Under coupling effect, the landslide will in less stable status than undertheir individual effects. Rainfall plays a promoting role in some degree.