Quantifying the impact load of rapid dry granular flows exerted on rigid slit structures using centrifuge experiments and DEM simulation

Granular flows are typical hazard in mountainous terrains. Slit structure has been shown to be a successful mitigating strategy. However, the interaction mechanism between granular flows and slit structure has not been completely elucidated, and the impact load and impact pressure distribution pattern of granular flow on slit structures also has not been fully discussed. Therefore, a novel centrifuge flume experiment and DEM simulation were designed. The centrifugal acceleration field and Coriolis field accounting for the Coriolis effect were also implemented in the DEM model. Results reveal that, the grain size almost has no effect on normal impact forces when the granular flows act as continuous characteristic, and the initial volume and impact force do not show a simple linear relationship. Furthermore, the impact pressure profiles indicate a trapezoidal distribution with a peak impact pressure at the bottom and a decline from the bottom to the top. In addition, the impact forces also showed a decreasing trend from the slit to the flume channel sidewall, making the inner part vulnerable. This study might contribute to the study of flow-slit structure interaction and provide scientific support for slit structure engineering design.