Quantitative 3D simulation analysis of debris flow impact effect based on SPH

The debris flow is a multiphase mixture. The traditional numerical model based on Bingham and Herschel-Bulkley-Papanastasiou (HBP) constitutive relations cannot simultaneously represent the viscous and elastic properties of the fluid, so it is difficult to accurately describe the rheological characteristics of the debris flow. In this work, the Oldroyd-B constitutive model is used to characterize the motion characteristics of the debris flow. The suitability of the Oldroyd-B model in the SPH framework is verified by one-dimensional steady Poiseuille flow, and the model parameters are calibrated by laboratory tests. Finally, the impact force and energy loss of the debris flow are simulated by different baffle structures. The calculation results show that the Oldroyd-B constitutive model can well characterize the debris flow movement properties. A combined baffle model was proposed by comparing different heights, shapes and spacings of baffle. The research results can provide a new research method and idea for debris flow disaster prevention and mitigation.