SPH-DEM MODELLING OF TSUNAMI DRIVEN FLOATING DEBRIS AND ITS TRAPPING BY COASTAL FOREST

摘要

This paper applied a three-dimensional approach for Smoothed Particle Hydrodynamics (SPH) based on particle approximation for modelling an inland surge due to aftermath of tsunami and Discrete element method (DEM) representing solids like trees and floating debris. The aim is to predict the behaviour of particle-fluid interaction and understand the trapping action of debris by finite-length forest considering the effects of forest density and aspect ratio of the forest by SPH-DEM coupling. In order to investigate the behaviour of floating debris and their interaction with forest, the model was validated and the flow pattern of the debris simulated by the model is in good agreement with the experimental study. Further, the debris flow behaviour pattern was explored for different type of debris such as shipping container. The simulation results based on the open source code DualSPHysics of SPH-DEM model were capable of capturing the debris flow pattern and identified the most critical cases which exerted the overturning pressure to trees. Practical application of this study will further help to design the inland forests that can trap debris or slow their propagation in front of a refuge.