Wave forces on crown wall of rubble mound breakwater under swell waves

Abstract

Crown walls are often used to reduce costs and increase the top of the rubble mound breakwater. Swell period waves often occur along the coast of South Asia, Africa, and South America and have attracted increasing attention. An experiment consisting of 744 tests was conducted to study the wave force on the crown wall under swell waves. Pressure transducers of 100 and 1000 Hz were arranged on the crown wall. Through comparison, the acquisition frequency of 1000 Hz can capture greater impact pressure than 100 Hz. The effects of wave height, water depth, wave period, slope, and berm width on the wave force were studied. Subsequently, experimental data were compared with the Pedersen, Martin, Nørgaard, and Code of China Design methods, and the applicability of these methods was analysed. A linear modified method was proposed to improve the original Pedersen, Martin, and Nørgaard methods. The results indicated that the improved methods have significantly smaller errors than those of the original methods. The improved Martin method was found to be the most effective in estimating horizontal force. The improved Nørgaard method was the most accurate for determining the uplifting force.