NUMERICAL ANALYSIS ABOUT MOVEMENT OF TSUNAMI BOULDER AND STORM BOULDER WITH SPH METHOD

Abstract

 Recently, number of researches by numerical simulation with GPU is increasing to solve complex phenomenon because of improving of processing capacity of GPU. Smoothed Particle Hydrodynamics (SPH), which is a Lagrangian meshless method, is known as very useful method for large deformation problems, such as movement of wave absorbing blocks and sliding of a caisson breakwater. Also, in coastal area, boulders launched by tsunami and by high waves with typhoons (named tsunami boulders and storm boulders) are focused on because of risk assessment towards the tsunami or super typhoons. However, the difference of their movement mechanism have been rarely investigated in detail. This study aims to simulate the movement of tsunami boulders and storm boulders, comparing with the hydraulic experiment, and evaluating the transport characteristics. Wave elevation and boulder displacement were fairly reproduced in the numerical wave flume compared to physical model. Also, wave action direction and overturning moment are different because solitary wave act boulders before wave breaking, whereas, irregular wave act them after wave breaking. It is suggested that this difference can identify tsunami boulders and storm boulders.