Critical soil thickness analysis and stability prediction of slope

Abstract In order to realize the prediction on the slope stability,the slope in Dingjiafen in Chuxiong, Yunnan, China was selected as the worksite to be studied,the critical soil thickness (Dcr) when the landslide was started under saturated condition of slope and the maximum soil thickness（Dmax）when the landslide was started under unsaturated condition of slope were inferred by using the slope stability physical model. Based on digital elevation model (DEM), the critical soil thickness and maximum soil thickness of each slope unit at the start of landslide were calculated,the criterion of slope instability was determined, and the influence of rainfall infiltration process, soil thickness, the physical and mechanical properties of soil, slope surface and the bedrock surface topography on slope stability was analyzed.The analysis results were verified by means of modeling and numerical simulation calculation of FLAC3D. The research results shows that the critical soil thickness and the maximum soil thickness of the slope unite with different topographies at the start of landslide are not the same. Besides, the slope units with the critical soil thickness between 1m~3m were located at the right and left side of the Chu-Meng highway, which conformed with the actual position of sliding. Simulating the thickness of soil layer when slope units were at the critical state of landslide by using this method can predict the stability of slopes.