Characterization and prediction of the effects of random factors on buffering efficiency in slope-cushion layer collisions through the discrete element method

This study developed a numerical model based on the discrete element method to investigate the characteristics of a granular slope-cushion layer during collision. The model considered the influence of cushion particle radius, incidence velocity, cushion thickness, and initial rotational angular velocity. The results indicated that a larger cushion particle radius generated a stronger impact force and a higher percentage increase (up to 34%) in the impact force. The counterclockwise initial angular velocity of the rockfall facilitated the splashing of the cushion particles at the bottom of the slope cushion. The clockwise motion of the rockfall results in its bouncing on the surface of the slope–cushion system. Using the normalization method, the maximum impact force, penetration depth, and energy dissipation ratio were fitted as functions of cushion thickness. The results of this study provide a solid theoretical foundation for the design of slope-cushion layers.