Numerical simulation of debris flow movement and accumulation processes based on particle flow theory

Studying the movement process of debris flows is of great significance for predicting their disaster-causing range and implementing reasonable prevention and control measures.The dynamic characteristics of debris flows are complex and variable, and their movement process often involves large deformation issues.When using traditional grid-based numerical methods for calculation, it is easy to cause grid distortion and twisting problems.Therefore, this study adopts the Smooth Particle Hydrodynamics (SPH) method to model the movement and deposition process of debris flows.To validate the proposed method, numerical simulations of debris flow movement and deposition processes were conducted using small-scale model channels and debris flow experiments in small streams.The results showed that the HBP constitutive model effectively fitted the measured rheological properties of the fluid, and the numerical simulation results slightly preceded those of the Cross and Bingham models during the initial stage of fluid movement, demonstrating higher accuracy.The constructed structures hindered the movement of the debris flow, reducing the peak flow velocity at the gully mouth by 0.97 m/s.That is, the constructed structures delayed the movement of the debris flow, reduced its velocity, caused the leading edge of the debris flow fluid to accumulate in advance, and reduced the extent of the debris flow.The study provides a theoretical basis for predicting the movement path and disaster-causing range of debris flows.