Reduction of Wave Pressures on Vertical Seawall/Caissons Due to an Offshore Breakwater

Estimation of wave pressures on vertical impermeable caissons and seawall is needed to determine the dimensions and appropriate material selection of the structure. Reduction of extreme wave loadings (pressures) by constructing an offshore breakwater on seaward side of these structures is investigated. A series of physical model tests were carried out in a wave flume to examine the performance of the defense structure (offshore breakwater) in reducing the wave pressures on the seawall/caisson. Quasi-static nature of the wave pressures was observed due to piling-up of fluid mass behind the breakwater. The influence of the pool length on reduction of pressures on seawall/caisson is also investigated for regular waves.