Numerical investigation of landslide kinetics for the recent Mabian landslide (Sichuan, China)

Using the particle flow code (PFC), this work analyses the kinetic features of a landslide which occurred on May 5, 2018 in Mabian, Leshan City, Sichuan Province, China. The analysis is based on geological field investigations and unmanned aerial vehicle (UAV) images. The micro-strength parameters corresponding to the macroscopic characteristics of landslide rock materials are inverted by the method of the support vector machine (SVM) and PFC coupling. Coupled with digital elevation model (DEM), a PFC3D numerical model of this landslide is constructed, and the slope failure process is simulated. In the kinetic analysis, the landslide velocity, displacement, and energy features are taken into account. The results show that the initial stage of a landslide begins with the acceleration of the overall movement, followed by the debris flow deceleration movement. Its total movement duration is about 32 s, of which the main sliding time is about 16 s. The maximum velocity of the landslide mass is 10.2 m/s, and the maximum displacement is 120 m. The kinetic energy of the landslide dominates in the acceleration stage, and the collision and friction energy dissipation dominate in the deceleration phase. The simulation results are in good agreement with the real landslide characteristics and the video interpretation of the landslide motion process. This work could provide a new way to study related landslides as well as a theoretical reference for the quantitative risk assessment and disaster prevention and mitigation of landslides in the area.