WIND EFFECTS ON WAVE OVERTOPPING DISCHARGES AT DIKES AND BREAKWATERS WITH A CREST WALL

Estimates of wave overtopping generally determine the required crest level of coastal structures. Wind affects wave overtopping, especially for coastal structures with crest walls because these can cause a vertical wave motion above the crest that is susceptible to wind. Within the relevant range of overtopping discharges, the expected wave overtopping discharge at coastal structures with a crest wall can be up to 5 times larger than for situations without wind. For smaller discharges the influence factor for wind can be significantly larger. In the present study based on physical model tests the maximum influence of wind on wave overtopping discharges has been studied for (impermeable) dikes and (permeable) rubble mound breakwaters with crest walls. The influence of wind on wave overtopping is mainly determined by the magnitude of the overtopping discharge itself and by the height of the crest wall. The result of the study is a guideline to estimate the maximum influence of wind on wave overtopping at dikes and rubble mound breakwaters with a crest wall.