Wave Transformation between Submerged Breakwater and Seawall

This paper presents the experimental results of wave transformation between a submerged permeable breakwater and a seawall including variations of the wave profile, the piling-up of water and the wave run-up. The results show that the wave height transformation behind the submerged breakwater varies in spatial due to the transmitted wave being reflected from the seawall. The energy transfer from the fundamental harmonic to higher frequencies due to the submerged breakwater was also investigated. The piling-up of water behind the submerged breakwater also varies spatially, where the maximum occurs about in the middle area of these two structures. The height of piling-up decreases as the freeboard of the breakwater increases, from which the empirical equation is presented in this paper. As comparing to the case of no submerged structure in front of a seawall, the result shows that the installation of the submerged permeable breakwater is capable of reducing the wave run-up on the seawall efficiently.