Wave Overtopping Behavior on the Rear Side of Composite Type Breakwater

Abstract

Wave overtopping caused damage not only on the front side of the breakwater, but also on the deck and the rear side of breakwater structure. In this study, the behavior of wave overtopping flows on the deck and falls on the rear side of composite breakwater were investigated. A series of physical experiment with changing wave periods and wave height of a regular waves were carried out to identify the relationship between the wave conditions and overtopping flows. The Bubble Image Velocimetry (BIV) technique and digital image analysis were applied to measure the velocity in the aerated region. The measured velocity shows that the velocity on the deck were dominated by the horizontal velocity component. Wave overtopping volume and rear edge velocity shows a positive linear relationship with wave height. On the rear side, the plunging distance of overtopping jet shows a logarithmic trend as wave height, wave period and rear edge velocity increased. While the plunging velocity shows a linear relationship with those parameters. Moreover, the angle created by the plunging velocity component has exponential relationship with wave height, wave period and rear edge velocity.