Numerical Research on Temporal and Spatial Evolution Law of Debris Flow Impact Force Based on in-situ Model

Abstract

Debris flow is a huge hazard to downstream lives and property, which must be controlled by engineering. The construction of gravity sand retaining dams (hereinafter referred to as sand retaining dams) from the formation area to the circulation area is one of the quick and effective measures. Prevention and control projects often play a role in controlling the development trend of debris flow and reducing the size and frequency of debris flow. Debris flow will cause erosion and impact damage to the dam foundation of sand retaining dams. For the debris flow impact force, the most dangerous part is usually designed based on the largest impact force, while all parts of the dam body are designed according to the most dangerous part, which wastes materials. It's not economical. In this study, a debris flow gully is selected as the research model. Considering the interaction between debris flow and sand retaining dam, the impact simulation of debris flow on sand retaining dam was carried out. The research results show that the existence of the sand retaining dam hinders the movement process of debris flow, changes its speed and direction of movement, and in addition, the impact force varies at different places of upstream face of sand retaining dam. Research results provide a scientific and reasonable theoretical basis and design reference for the stability of sand retaining dam under debris flow impact impact. This will, to a certain extent, have important social needs and practical significance for disaster reduction to improve the technical level of debris flow prevention projects.