Analyzing And Evaluating The Stability Of Welfare-institute Landslide In Zhangmu Town Of Tibet

Zhangmu town is located in the left bank of Boqu canyon in the south foot of Himalayas in southwest Tibet. There are many old-landslides in this area. In the recent 20 years, with the variance of the climate and the increasing of man-made project, many shallow soil sub-landslides have developed on the prominent opening boundary position in these old-landslides. These landslides, especially the new sub-landslides have serious threat to the local people's lives and property and the development of the local economy.Take the analysis and appraisal of stability for the welfare-institute landslide and its sub-landslide as the main researching congtent, on the basis of fully studying the physical geography and engineering geology condition,this article makes a thorough study on the main landslide and the sub-landslide, and makes a detailed analysis for the shape features,deformation features,material features,geotechnical parameters and the Fos of the wafare-institute landslide and its sub-landslide. On the bass of analyzing the stability factors, this article considers that water is the most important stable factor and earthquake and human engineering activities are also very important for the stability of the welfare-institute landslide and its sub-landslide. This paper adopts qualitative analysis and transfer coefficient method and the software FLAC3D to calculate and analyze the stability of the landslides in natural state and water-saturated state.The result shows that in natural state the main landslide and the sub-landslide are all stable, and in water-saturated the main landslide is stable but the sub-landslide critical stable. The result has a good agreement with the fact of practical observation.