Numerical Simulation of Debris Flow incurred by Earth Dam Collapse

More than 70% of domestic reservoirs in Korea are earth dams that are more than 50 years old, and until recently, large and small reservoirs have repeatedly collapsed and resulted in damages. However, most of the domestic and foreign techniques of reservoir collapse simulation, which are used as the techniques for damage prediction, are not only based on two-dimensional flow analysis, but are also performed by ignoring the dam collapse process. The dimensional flow, of course, has limitations that do not reflect the effect of the soil mass at the beginning of the collapse. To compensate for the limitations, we used computational fluid dynamics to simulate the collapses of reservoir collapses with three-dimensional Navier-Stokes equations and assumed the multiphase flow technique of soils as three phases of soil, suspension, and air. . In addition, the Herschel-Bulkely fluid was modified to take into account the water content and concentration of the soil, and the coulomb-viscoplastic fluid was introduced to simulate the nonlinear viscosity of the initial soil breakdown by considering the interaction inside the soil. Using 3D simulation techniques, 3D simulation was performed on the assumption of total collapse and partial collapse of the mountain reservoir collapse in 2013. Prediction and comparison of inundation ranges were made and comparison with the inundation area created through previous studies. This research was supported by a grant (2018-MOIS31-009) from Fundamental Technology Development Program for Extreme Disaster Response funded by Korean Ministry of Interior and Safety(MOIS).