Analysis of the impact force of debris flows on a check dam by using a coupled Eulerian-Lagrangian (CEL) method

摘要

The dynamic impact force of debris flows on a check dam was investigated by using numerical analysis and an analytical investigation. The emphasis was on quantifying the magnitude and distributions of the dynamic impact force due to the moving debris flows and the static force due to the deposited material of debris flows. The behavior of debris flows on a check dam and the corresponding response of the significant factors influencing the dynamic impact force of debris flows, such as the entrainment of the soil layer, thickness of sedimentation, and flow velocity, were analyzed by using a three dimensional coupled Eulerian-Lagrangian (CEL) approach. The prediction method can adequately analyze the behavior of debris flows involving the entrainment of the soil layer. The obtained results indicate that the impact force of a debris flow with a high flow velocity cannot be predicted accurately by using the conventional static empirical model, especially when the dynamic empirical model is overestimated. The proposed method was verified by comparing the characteristics of the laboratory test results and the actual debris flows that occurred in Mt. Umyeon, South Korea in 2011.