Impact Model for Baffle Design Resisting Granular-Flow Disasters

Abstract

Baffle structures are effective measures for decelerating granular flows and reducing their destructive power. However, the engineering design of baffle structures, particularly with respect to their height and strength, requires estimation of the run-up height and impact force, respectively, and remains challenging and immature. To describe the debris–baffle interaction, we propose an analytical model that incorporates the Froude number and ratio of the slit size to the particle size. The proposed model was verified based on numerical data. In this paper, we first discuss the determination of the empirical coefficients adopted in the proposed model. Then, using the flow properties of free flow in the proposed model, the calculated run-up height and total impact force on the first baffle array are compared to the results obtained by discrete element modeling. With regard to engineering design, the performance of the proposed model with a correction strategy and the baffle design considering unsteady-state flow dynamics are discussed in detail. The findings of this study suggest that the global maximum flow velocity and flow depth should be adopted in the engineering design of baffle structures.