Irregular Wave Overtopping of Seawalls

This paper discusses recent laboratory tests of irregular wave overtopping of coastal structures being conducted at the Coastal Engineering Research Center (CERC). Current model tests of seawalls has led to an improved method for predicting wave overtopping rates. Structures tested included seawalls fronted by a variety of riprap revetment configurations as well as a seawall with no fronting revetment. Overtopping rates have been found to be strongly dependent on a dimensionless parameter, F' , which is the ratio of the freeboard of the seawall to a measure of the severity of the incident waves. The parameter, F' , contains several variables including the crest elevation of the seawall, the local water level and depth, the zero-moment wave height, and the period of peak energy density of the wave spectrum. A simple exponential model incorporating F' is useful for evaluating and comparing the performance of various seawall/revetment configurations and can be used to compute realistic wave overtopping rates.