Large-scale experimental study on hydrodynamic performance of a permeable breakwater with prefabricated self-centering wave walls

To facilitate rapid construction and improve the structural mechanical property and wave dissipation performance of breakwaters, a new type of permeable breakwater installed with prefabricated self-centering wave walls (SCWWs) is proposed in this study. A 1/5-scaled physical model is designed and tested in a large wave flume under regular waves to investigate wave force characteristics, structure response, as well as wave dissipation performance of the proposed breakwater. Experimental results show that the wave force and displacement responses of SCWWs exhibit periodic characteristics, with the positive wave force and positive rotation displacement under wave crest conditions being dominant. The proposed breakwater remains damage-free, and SCWWs can always return to the original position even under large wave heights thanks to self-centering capability. The experimental wave pressure distribution on SCWWs agrees well with the theoretical solutions. Wave forces acting on SCWWs increase obviously with relative wave height, while wave period has a limited influence. The proposed breakwater exhibits favorable wave dissipation performance, attributed to the energy dissipation function provided by the bottom horizontal platform, openings in SCWWs, and middle chamber. Parametric studies demonstrate that relative wave height and water depth significantly affect the transmission and reflection coefficients by promoting wave overtopping, and wave steepness enhances wave energy dissipation capacity.