SPH SIMULATION OF LOCAL SCOURING ON RUBBLE MOUND DUE TO TSUNAMI OVERFLOW

Abstract

After the field survey of structural damages in Tohoku earthquake disaster, coastal engineers recognized the importance of persistent coastal structure to reduce tsunami inundation on coastal area. In order to realize the persistent structure, it is important to understand the mechanism of structural damage under tsunami actions. This study focuses on the failure of breakwater caused by the local scouring on a rubble mound due to tsunami overflow. The problem of the local scouring due to tsunami overflow includes complex interactions between vortex flow and rubble mound. This study employs a numerical simulation method based on SPH model to reveal the characteristic of rubble mound deformation under several tsunami overflow conditions. Furthermore, this study proposes a countermeasure that consists of a horizontal plate to check the rubble mound scouring. Efficiencies of this countermeasure are also investigated in this research.