Large deformation FE analysis of a debris flow with entrainment of the soil layer

A study was conducted to understand the fundamental characteristics of debris flow in a watershed with entrainment of the soil layer. This paper presents the application of the coupled Eulerian-Lagrangian (CEL) technique to simulate three-dimensional debris flow with entrainment of the soil layer. To simulate the erosion and entrainment of the soil bed sediment, a softening model was adopted for the soil layer to describe the strength reduction of the erodible soil layer as a function of the velocity. The analytical method is validated using published data from a laboratory experiment [1]. This comparison shows that the proposed model is in good agreement with laboratory data. Furthermore, FE analysis is conducted to ensure its ability to simulate the watershed scale debris flow. The validity of the analytical technique and model was evaluated by comparing the simulation against measured [2] debris flow. The results of the analysis show that the erosion and entrainment of the soil layer increase the volume of debris flow. The results are in good agreement with the measured phenomenon.