Experimental study of wave force on breakwater head under oblique waves

Abstract

The head of a breakwater warrants special consideration to achieve the necessary stability at vulnerable part of its structure. To widen the entrance to a harbour, a caisson is used for the breakwater head. Therefore, the wave force on the caisson head under oblique waves was analysed in this study. Physical model tests were performed in a wave tank, where wave loads on two weathering sections (S1 and S2) of the caisson head were measured under oblique-regular and irregular wave attacks. The results have shown that the improved Goda’s method can predict the wave forces on the caisson head. The wave forces on the two sections increased with an increase in the period under different incident angles. The phase lag between the horizontal forces on S1 and S2 was evidently influenced by the incident angle. The relationship between the maximum wave force on one section and its accompanying wave force on another section was described, and the results have demonstrated that under the same incident angle, as the period increased, the maximum wave force of S1/S2 is gradually equal to its accompany wave force of another section.