Experimental validation of a new semi-empirical impact force model of the dry granular flow impact against a rigid barrier

The maximum impact force of granular flow and its action point on a rigid barrier are the key indices of the anti-slip and the anti-overturning calculation, respectively. On the basis of the present impact force models and the observation in model experiments, this paper proposes a new semi-empirical impact force model focusing on the normal impact force and its point of action. By comparing the analytical solution and the experimental results, the new semi-empirical analytical model can estimate the normal impact force composed of both dynamic and static components with an error margin within +/- 20% compared with the experimental results and so is for the corresponding point of action and tangential force. To calculate the residual force generated only by the static dead zone, the static friction angle between the dead zone and the chute base should be less than what was measured under kinetic conditions. Based on a large number of tests, it was found that assuming that the reaction force generated by the chute base operates at 2/3 of the deposition length makes the estimated normal impact force best suited to the experimental results.