Factors Influencing the Collapse of Granular Columns Based on Discrete-Element Simulation

In this study, model tests on the collapse of sand granular columns are designed to investigate the relationship between the initial stacking height and the maximum run-out distance of the granular column, and the results were used to calibrate the discrete-element model of the granular column. Based on this calibrated model, the morphological characteristics of the relative stationary zone and the influencing factors were studied. Nine sets of numerical models were designed to investigate the impacts of particle size, porosity, and particle gradation conditions on the collapse process of the granular column and to explain the deposition shape in terms of kinetic energy. With the increase in the particle size, the normalized maximum run-out distance after the collapse of the granular column increased, the height after deposition decreased, and the inclination decreased. With the increase in particle porosity, the height after deposition of the granular column after collapse, the volume of the relative stability zone, and the maximum run-out distance of the particles all decreased. When the granular column gradation was continuous and the coarse, medium, and fine particles were evenly distributed, the kinetic energy of the granular column was the highest, and the run-out distance was the farthest.