Kinetic response analysis of different types of baffle submitted to rock avalanches based on discrete element method

Taking the disaster prevention and mitigation project for Ermanshan landslide as the research object, this study conducts the physical model test of rock avalanches and uses three parameters of Sc  (column spacing), Sr (row spacing), and Ld (the distance between the first row of the array of baffles and the chute port) to determine the optimal layout of three different types of array of baffles (square baffles, circular baffles, and arc-shaped baffles). Then, PFC3D is used to build a numerical simulation model of rock avalanches–array of baffles–retaining wall. Finally, this paper compares the impact force on each baffle type under the optimal layouts as well as the displacement and impact force on the retaining wall of the array of baffles. The results show that the impact force of rock avalanches on the array of baffles and retaining wall decreases with the increase of Sc. As Sc increases from 2.5 to 4.5, the average impact force on the circular baffles, square baffles, and arc-shaped baffles is reduced by 26.4%, 17.1%, and 23.4%, respectively. Besides, under the different layouts, the arc-shaped baffles show the best effect of blocking and energy dissipating among the three. Under the same working conditions, the average impact force on the first row of arc-shaped baffles is lower than that of the circular baffles and square baffles by 12.5–22.5% and 2.1–10.1%, respectively. Moreover, the arc-shaped baffles have an advantage in dissipating the impact force. Under the S2 working condition (S2: the optimal configuration for square baffles system), the maximum impact force on the first row of the circular baffles and the square baffles is increased by 21.3% and 14.9% compared with the S1 working condition (S1: the optimal configuration for circular baffles system). The chute shape of the arc-shaped baffles can form a cushion under the condition of particle accumulation, resulting in that the maximum impact force on the first row of the arc-shaped baffle under S2 condition is reduced by 17.3% compared with that under S1 condition.