Experimental Study on the Accumulation Characteristics and Submergence Degree of Three-Dimensional Granular Rock Landslides in Shallow-Water Areas

This study combined the characteristics of rock mass structure, channel characteristics of main and tributary rivers, and flow conditions in the Three Gorges Reservoir area of the Yangtze River and designed and constructed a three-dimensional granular rock shallow-water landslide surge model test system under dynamic water flow conditions. The main influencing variables, including the volume of the landslide body, the inclination of the sliding surface, the water depth of the channel, and the flow velocity, were determined. A four-factor four-level orthogonal test design and a single-factor test design were combined to determine 28 sets of test conditions. Based on existing field surveys and physical model test simulation results, the motion process of the landslide body was divided into four stages: starting, accelerating, slowly accelerating or decelerating, and rapidly decelerating. The variations in the motion and velocity of the landslide body over time were determined by analyzing the image sequence extracted using a high-speed camera. The morphological characteristics of the landslide accumulation body were analyzed, and the submerged rate of the landslide body was statistically calculated. The relationship between the maximum bottom width of the landslide underwater accumulation body and the volume of the underwater accumulation body was established.