Rocking motion and overturning failure of caisson breakwater

Sliding and overturning are the main types of caisson breakwater failures. Sliding failure is related to the sliding motion and overturning failure is related to the rocking motion. In this paper, a model of vibrating-rocking motion of caisson breakwater under breaking wave impact is presented, which can be used to simulate the histories of vibrating-rocking motion of caisson breakwater. The effect of rocking motion on the displacement, rotation, sliding force and overturning moment of breakwater is investigated. It is included that the caisson may only rock in case the overturning moment exceeds the stability moment of caisson and the caisson overturns only in case the rocking angle exceeds the critical angle. The design idea that the rocking motion should be allowed in breakwater design is proposed.