Formation Mechanism of Soft Foundation Landslide Based on Numerical Simulation of Discrete Element

The soft foundation slope has a double slope structure with "hard and soft", and its deformation failure mode and instability mode are also complex. In order to analyze the denaturing failure mechanism of this type of slope in detail, an ancient landslide with such characteristics of slope structure was taken as an example, based on field investigation, geological analysis method and discrete element numerical simulation method are used to explore the formation process of landslide. The deformation and failure process of slope under natural, rainfall and seismic conditions is analyzed. The results are as follows. Active geological period, steep terrain, complex geological structure and double slope structure constitutes the necessary conditions of the landslide formation. Rainfall and earthquake are the main external factors. It is inferring that the landslide is characterized by a composite instability mode with toppling deformation and sliding and compression cracking. The slope deformation and failure process under different conditions such as gravity, rainfall and earthquake is simulated by using discrete element numerical simulation. The results show that both rainfall and earthquake can cause landslides. However, the earthquake type landslide has the characteristics of shorter duration, larger scale and farther motion distance.