Hydrodynamic characteristics of emerged modular porous reef breakwaters

ABSTRACT The wave interaction with porous reef breakwaters is investigated in this study through extensive laboratory experiments. The research is focussed on bringing out the hydrodynamic characteristics, such as wave transmission and wave reflection coefficient of reef breakwaters in emerged conditions. Design equations for estimating the transmission and reflection coefficients for emerged porous reef breakwaters are presented. The developed equations will be beneficial in deciding the dimension of the reef breakwaters for a given wave condition. The presence of Reef-Induced wave Breaking (RIB) was observed for certain combination of wave and reef parameters. The effects of hydrodynamic processes observed during the study, namely, RIB and overtopping in relation to the performance of the emerged porous reef breakwaters is discussed. Furthermore, the wave-induced pressures exerted over the reef breakwaters are measured on the seaside, leeside and at the midsection of the reef breakwater. A thorough analysis has been carried out to ascertain the magnitudes of hydrodynamic pressures which has got an important bearing in understanding the magnitude of wave induced forces on the reef breakwaters. Through detailed parametric investigations, the study brings out the parameters that govern the hydrodynamic performance and wave-induced pressures over the emerged reef breakwaters.