HYDRAULIC EXPERIMENT AND NUMERICAL SIMULATION OF MOUND SCOURING BEHIND BREAKWATER INDUCED BY TSUNAMI OVERTOPPING

Abstract

 Fall flow due to tsunami overtopping causes scouring on mound behind breakwater, which finally results in failure of caisson breakwater. The scouring process includes complex interactions as well as highly deformed interface between fluid and solid phases. Due to aforementioned difficulties, both numerical and experimental investigations toward scouring mechanism has not been sufficiently investigated. In this regard, fully Lagrangian numerical method, namely particle method, is supposed to be an appropriate candidate to tackle this issue owing to its distinct advantage in dealing with complex boundaries. In this study, both experimental and numerical studies on mound scouring are carried out. For numerical simulation, one of Lagrange-Lagrange coupling methods, namely DEM-MPS, is utilized for 3D simulation of scouring on mound behind breakwater. The performance of DEM-MPS method and its potential applicability toward scouring problems are validated by comparing the reproduced numerical results with those of conducted model experiment.