Perforated caisson breakwaters:: Wave loads and hydraulic performance

Since few years new designs of very little reflecting breakwaters are used to protect coastal or portuary installations. And within the framework of the Research Program European MAST III - " PROVERBS ", specific studies on the breakwaters to perforated wall were carried out. Laboratory and field measurements of pulsating wave pressures, wave forces and reflection performance of different types of perforated caissons carried out by ENEL, LWI, PM and GMFGC/UC have led : to a better comprehension of their behaviour, and to know their hydraulic functioning in order to optimize the performance to know the instantaneous forces and propose a method of calculation for the design of this structures. In this paper an analysis of the performance of these structures under pulsating wave load conditions is given and new methods based on Goda-type formulae are proposed to estimate the overall forces for caissons with either open or closed ceiling chamber.