Physical Simulation Test Of Fragmentation Mechanism And Accumulation Characteristics Of Rock Avalanche

Due to its super-strong motion characteristics,rock avalanche often cause huge casualties and property losses to humans,so it has become a hot spot for scholars from all over the world.At present,there is no unified theoretical explanation for the super-strong motion mechanism of rock avalanche.In this paper,the movement characteristics and fragmentation characteristics of high-speed and long-distance landslides of debris flow patterns are studied through case studies and physical simulations.The typical feature of a rock avalanche is that it continuously fragments and forms a debris flow during its movement.The particle size of its particles is directly related to the movement ability of the debris flow.In this paper,by investigating the geomorphological and sedimentological characteristics of the rock avalanche in Walai,the kinematics and fragmentation characteristics of the rock avalanche are summarized,and physical simulation tests are carried out based on the actual characteristics of the Walai landslide.Research and analysis of the movement process,fragmentation mechanism,and accumulation characteristics of the vehicle.This article first analyzes the geometric characteristics(movement distance,area,volume)and geomorphology characteristics(pruning line,slope change)of the Walai landslide from the perspective of geomorphology through field investigation of the Walai landslide;based on the perspective of sedimentology,The fragmentation process of the Walai landslide was discussed from the sedimentary structure and grain size characteristics.Relying on the understanding of the movement process of the Walai landslide(falling,sliding;strong fragmentation-weak fragmentation),this paper carried out a physical simulation test of fragmentation of rock avalanche.The test work includes five parts: device construction,similar material preparation,test plan design,physical simulation test,result processing and analysis,and tested the impact of terrain conditions and volume changes on landslide fragmentation and movement capabilities.Based on the results of field investigation and indoor analysis of the Walai landslide,as well as the results of physical simulation tests,the following conclusions are obtained:1.The Walai landslide is an anti-dipping landslide controlled by joint planes.It is a wedge type failure.The movement distance reaches 3487 meters.The volume of the landslide source area is 4.1×107m3.The center of mass ratio is 0.32,which is a typical debris flow pattern.rock avalanche.2.Through analysis of topography and geomorphology and grain size,the accumulation structure mainly includes layered structure,reverse order structure and puzzle structure.The grain size characteristics of the accumulation did not change significantly with the change of the movement distance;the movement process can be divided into the strong fall In the crushing stage and the sliding weak crushing stage,the former is controlled by collision and crushing,and the latter is controlled by shearing.3.Research on the fragmentation mechanism and accumulation characteristics of the Walai landslide with the aid of physical simulation tests.It is found that the layered fragmentation phenomenon occurs in the strong crushing stage,and at the same time,it provides the source of the subsequent reverse structure and jigsaw structure;when the sample movement encounters obstacles,the sliding particles in the front will collide and throw away.The description of the landslide is consistent;the increase in the number of obstacle bars increases the sliding resistance of the sample on the slope,which leads to a decrease in the speed of the sample and a decrease in the impact force during collision.Therefore,when the specimen moves to the plane,the degree of fragmentation decreases,and the distance of the plane movement increases;with the increase of the initial volume,the farthest stroke of the specimen exhibits a logarithmic increase trend.