Laboratory Investigations on Wave Run-up and Transmission over Breakwaters Covered by Antifer Units

Abstract

The e ect of a placement pattern of antifer units on the wave run-up and transmission was investigated in more than 380 laboratory tests. The main variables in the experiments were as follows: An antifer unit placement pattern, the breakwater front slope angle, the incoming wave height and steepness, and the still water depth. It was concluded that the wave run-up can be reduced by about 25% by changing the placement pattern from regular to irregular. The measured data were also applied to estimate the wave run-up on the antifer-covered breakwaters as a function of the standard run-up on smooth and impermeable slopes. The measured data of the wave transmission are applied to inspect the prediction equations mentioned in literature, and the predicted and measured data were compared and the deviations were discussed. Some modi cations were proposed to improve the accuracy of prediction equations of the wave transmission, especially for breakwaters covered by antifer units in regular and irregular placements.