COMPARISON OF WAVE OVERTOPPING RATES FOR BLOCK MOUND, TERRACE-TYPE, AND VERTICAL SEAWALLS

抄録

 The overtopping rates and reflection coefficients of regular waves for a block mound seawall and a terrace-type seawall were studied through the use of large-scale hydraulic experiments and numerical simulations using CADMAS-SURF. Then, the results were compared with those for a vertical seawall. For the overtopping rates of irregular waves, the characteristic hydraulic phenomena were masked by data averaging because the wave conditions and the overtopping rates were generally averaged. Even if a wave-by-wave analysis is applied for irregular waves, the information gained using regular waves is required as a basis for the interpretation to understand the overtopping phenomena of individual waves. In this study, the effects of relative seawall height, wave period, incident wave height, and water depth in front of the seawall on the overtopping rate were analyzed in detail. Then, the overtopping characteristics of waves for block mound and terrace-type seawalls were explained through comparison with the overtopping rate for a vertical seawall. The results showed that the dimensionless overtopping rates for both block mound and terracetype seawalls were almost the same as that for a vertical seawall.