Experimental Investigation on Regular Wave Process through an Artificial Reef

摘要

Artificial reef (AR) can be regarded as a perforated breakwater when it performs as an auxiliary structure in beach nourishment. In this paper, a kind of artificial reefs made of cuboid reinforced concrete blocks, which has already applied practically in beach nourishment projects in Beidaihe, has been experimentally investigated on the wave attenuation process in terms of small and destructive waves. Regular waves with five sets of wave height and period were used. The reflection coefficient, transmission and dissipation coefficients were obtained from measurements. Wave and velocity processes near the reef were compared and analyzed. The reflection coefficient (K_r) is 0.10～0.29, with transmission coefficient (K_t) of 0.31～0.65 and the dissipation coefficient (K_l) of 0.05～0.59. It is a definite and stable regime that the AR attenuates the incident wave. The AR performs as a submerged breakwater for small wave. But it impacts on moderate waves by more dissipation than reflection, when the porosity character highlights. As for big incident wave, the dissipation and reflection effects of the AR can reach the limit due to the extra energy loss, which maybe in large proportion, caused by the natural breaking of big incident wave.