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# Numerical Simulation Study of Debris Particles Movement Characteristics by Smoothed Particle Hydrodynamics

## Shoji Ueta^{*,†}, Natsuki Hosono^{**}, Ryusuke Kuroki^{***}, and Yosuke Yamashiki^{*}

^{*}Graduate School of Advanced Integrated Studies in Human Survivability, Kyoto University

1 Nakaadachi-cho, Yoshida, Sakyo-ku, Kyoto, Kyoto 606-8306, Japan

^{†}Corresponding author

^{**}Center for Mathematical Science and Advanced Technology, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Kanagawa, Japan

^{***}Mizuho Bank, Ltd., Kyoto, Japan

Debris flow is an important natural hazard in mountain zone because it can threaten human lives with very little warning. Since laboratory experiments on debris flows at real scale are difficult to perform, numerical simulations are important in evaluating the impact of such flows. Among several candidate models, the smoothed particle hydrodynamics (SPH) is a particular attractive numerical method for this purpose. SPH is a particle-based numerical hydrodynamic method originally developed in the astrophysical field before extension to elastic bodies. Several works have already tested the applicability of SPH to debris flow, despite there are only few detailed validations. In this report, thus, we aimed to check the applicability of SPH to debris flows. Since the accurate treatment of the elastic bodies tends to be computationally expensive, we have developed a massively parallel SPH code. A comparison between laboratory experiments and numerical simulations using SPH showed qualitatively similar features, though there are differences in quantitive comparisons.

*J. Disaster Res.*, Vol.17 No.2, pp. 237-245, 2022.

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