Numerical simulation of landslide over erodible surface

Abstract

Background: Estimating the magnitude and intensity of landslides is a fundamental requirement in quantitatively evaluating the risks involved, and preparing a mitigation strategy. Though the physics-based dynamic model of landslide can predict the travel distance, kinematic velocity, and hazard zone, the effects of erosion and the excess pore water pressure during the dynamic process of landslide are often ignored. Results: In order to study these factors, a physics-based dynamic model of landslide considering erosion and excess pore water pressure is presented in this paper. A high-precision numerical method based on the finite volume method is proposed to solve the model equations. Several numerical tests are performed to verify the numerical method and the model. The effects of erosion and excess pore water pressure on the dynamic process of landslide are also analyzed. Conclusions: The numerical results indicate that the scale and mobility of a landslide are influenced by the effect of erosion and excess pore water pressure. The excess pore water pressure can reduce the resistance to shear stress from the erodible bed and lead to a higher erosion amount and longer moving distance of the landslide. It also affects the degree of erosion and further affects the dynamic process of the landslide. The sensitivity analysis of the parameters that influence excess pore water pressure indicate that these parameters have a significant impact on the evolution of excess pore water pressure, and that the degree of saturation of bed sediment has the highest influence on excess pore water pressure.