A FUNDAMENTAL STUDY ON TSUNAMI PROTECTION MEASURES FOR A VESSEL MOORED AT A WHARF CONSIDERING THE BACKWASH INFLUENCE

摘要

When a tsunami attacks in harbors, a vessel moored at a wharf is occurred a serious damage. The first wave of the tsunami has two forms and those are called the leading wave and the backwash. And, it is difficult to predict the form of the first wave of tsunamis. Authors have been studying about damage protection measures against the leading wave of vessels moored at wharves. However, it is also necessary that a damage protection measure against the backwash of vessels moored at wharves is considered. In this study, it is examined the damage status of a vessel at a wharf due to the backwash. Then, it is examined the influence of the backwash to the author's proposal tsunami protection measures. The three dimensional MPS (Moving Particle Semi-implicit) method is used. The Backwash is simulated as the dam break phenomenon. Outflow angles, flow velocities, mooring conditions and with and without of tsunami protection measures are considered.