Abstract
A series of hydraulic model experiments was systematically carried out to investigate hydraulic characteristics of tsunami overtopping flow over a caisson type breakwater, with considering various conditions such as caisson dimensions, with or without of a parapet and various combinations of water levels at front side and rear side of the breakwater. The experiment results showed that horizontal force acting on the rear wall of a caisson decreases as water level differences become large, compared with assumed static hydraulic pressure acting on the wall. In addition, a simple method was proposed based on the experiment results, which is capable of estimating the physical quantities of plunging flow fallen out from the caisson, such as velocity, plunging angle and position of the flow at the surface of the rear water level.
