2D PHYSICAL MODELLING OF WAVE-INDUCED FORCES AND OVERTOPPING ON VERTICAL CAISSONS WITH RETREATED CROWN WALL

Composite vertical breakwaters are monolithic coastal structures commonly employed for safeguarding harbor basins, particularly in deepwater microtidal conditions. Their design currently relies on Goda's formulae (Goda, 2010) or the probabilistic design tools (PROVERBS) proposed by Oumeraci et al. (2001). The overtopping performance of these structures can be predicted using tools outlined in the EurOtop Manual 2018. Due to the size of these structures, optimizing and enhancing their hydraulic performances, such as reducing wave loads and overtopping, can result in significant economic savings. The paper deals with a 2D physical model study of wave-induced forces on a composite vertical breakwater, where the position of the crown wall has been varied during the tests. This research aims to enhance understanding of the physical phenomena related to wave-structure interaction in composite vertical breakwaters with retreated crown walls, expanding the work of Romano and Bellotti (2023). To this end, a parametric study has been carried out through 2D small- scale physical model tests in Roma Tre University's wave flume (9.00 m long, 0.27 m wide, and 0.50 m high), equipped with active wave absorption. The objective was to study the increase or reduction in both wave loads and wave overtopping as a function of the position of the crown wall under non-breaking wave conditions.