Laboratory investigation on the effectiveness of an overspill basin in reducing wave overtopping on marina breakwaters

This paper presents laboratory experiments on scale models of marina breakwaters conducted to assess the effectiveness of an overspill basin in reducing wave overtopping. Six different breakwater models were tested under eight different wave conditions. The comparisons between the overtopping measurements on a classical shaped breakwater model and those conducted on models characterized by the inclusion of overspill basins have proved the effectiveness of this new design. Moreover, increasing the height of the wave wall up to the value that induces the same reduction of the overtopping obtained by the inclusion of overspill basins is also reviewed. Some analysis on mean overtopping discharges as well as analysis on maximum overtopping volumes are reported.