Wave Impact Load Decay Along Composite Breakwaters in Directional Seas

This paper discusses selected results from 3-dimensional model tests conducted by researchers from University of Naples, University of Sheffield, and HR Wallingford in the UK national Coastal Research Facility (CRF). The purpose of the work was to extend to composite walls previous analysis performed by Allsop & Calabrese to predict, in presence of directional seas, the reduction in the total load exerted by breaking waves on vertical walls. Experimental results on the load decay have been linked to a parametric characterisation of breaking wave sea states proposed by Calabrese which permits to discriminate the wave modes in front of the structures into three different categories (pulsating waves, impact waves and broken waves). The analysis appears to indicate a stronger effect of wave impacts on the force reduction in comparison with the influence of wave multi-directionality.