Experimental and numerical study on movement and accumulation behaviour of rock avalanche by simulating actual 3D terrain conditions

Fluidization is an important aspect of a rock avalanche, which differs significantly from a common collapse. In general, it results in a rock avalanche with a large velocity and area of deposition, both of which are frequently affected by terrain conditions. In this paper, we analyze the influence of several factors (particle size, particle-size distribution, volume, and number of batches) on the movement and accumulation of the Nayong rock avalanche in Guizhou Province, China. We first analyzed a laboratory-model experiment that simulated the actual three-dimensional terrain conditions, and we then employed the experimental results to optimize a numerical simulation of the entire dynamic process of this case study. The experimental and numerical results demonstrated that: (1) the travel distance and area of deposition are influenced significantly by the terrain characteristics; (2) the particle size, particle size distribution, volume, number of batches may have great effect on the movement and deposition area of a rock avalanche, with different factors exerting different effects under the terrain conditions, and some results here differ moderately from the conventional chute test results; (3) Laboratory model test results can guide parameter selection in numerical simulations, improving their accuracy.