Effect of water depth on wave reflection and loss characteristics of an emerged perforated quarter circle breakwater

Abstract

Quarter circle breakwater is a new-type breakwater first proposed by Xie et al. (2006) on the basis of semicircular breakwater. Quarter circle breakwater is usually placed on rubble mound foundation and its superstructure consists of a precast reinforced concrete quarter circular surface facing incident waves, a horizontal bottom slab and a rear vertical wall. A series of experiments were conducted in a two dimensional monochromatic wave flume on a seaside perforated quarter circle breakwater model. The present study investigates the wave reflection and loss characteristics on an emerged seaside perforated quarter circle breakwater of three different radii and with ratio of spacing to diameter of perforations equal to 5, for different water depths and wave conditions. The results were plotted as non-dimensional graphs and it was observed that the reflection coefficient increases with increase in wave steepness and increase in ratio of height of breakwater structure to water depth. It was also found that the loss coefficient decreases with increase in wave steepness and increase in ratio of height of breakwater structure to water depth. 2016 IJED.