ESTIMATION OF WAVE OVERTOPPING DISCHARGE ON MARITIME AIRPORT SEA-WALLS FACING ENCLOSED COASTAL WATER AREA

Abstract

 In this study, we estimated the wave overtopping discharge on airport island seawalls with multi-directional multiple reflection waves using the Boussinesq model (NOWT-PARI) and the direct fluid analysis method (CADMAS-SURF). The incident wave direction was set as the predominant wave direction, and the incident wave height was estimated from the superposed wave height at 0.7 wave length offshore from the seawall in normal direction and the reflection coefficient obtained by Goda's wave separation method. The validity of these estimates was verified by the calculation results using the Boussinesq model with a non-reflective boundary at the target seawall. Since the target seawalls are all multi-sectioned and covered with wave-dissipating structures, the effective crest height for oblique incident waves cannot be directly applied.

 Therefore, we applied the reduction rate of wave overtopping discharge for oblique incident waves, obtained from Goda's diagrams, to the wave overtopping discharge for perpendicular incident waves estimated by the direct fluid analysis method. This approach resulted in good agreement between the two methods, except in the case of alongshore wave overtopping.