Measurement of wave reflection in Combined Caissons with internal Rubble Mound

A laboratory investigation of wave reflection induced by combined caissons with internal rubble mound is here reported.Several experiments have been performed with the aim of providing indications about the effectiveness of combined caissons in reducing the reflection coefficient. The reflection of incident wave energy has been found to increase with the wave period. The best performances in terms of reflection coefficients are obtained when both the chamber width and the frontal opening are large.By analysing the effects of a slight variation of still water level, related for example to low/ebb tides or to the rise of still water level due to climate changes, it was found that some configurations induce a reduction of wave reflection when the water level increases, thus improving the performances of the combined caisson.