Failure mechanism and stability analysis of the Zhenggang landslide in Yunnan Province of China using 3D particle flow code simulation

Based on the principle of 3D particle flow code, a numerical landslide run-out model is presented to simulate the failure process of the Zhenggang landslide (in southwestern China) under the effect of water after a rainfall. The relationship between the micro-mechanical parameters and the macro-shear strength of the grain material is determined through numerical calibrations. Then the rainfall effect is considered in numerical simulations and rain-induced sliding processes are performed, which help us to discuss the mechanism of deformation and failure of this landslide together with field observations. It shows the Zhenggang landslide would most likely be activated in Zone Ⅰ and would gain momentum in Zone Ⅱ. In order to prevent the potential disaster, a tailing dam is advised to be designed about 175 m downstream from the current landslide boundary of Zone Ⅱ. Verified by field observations, the presented landslide model can reflect the failure mechanism after rainfall. It can also provide a method to predict the potential disaster and draft disaster prevention measures.