Wave overtopping of rubble mound breakwaters

A general expression for the overtopping discharge of a rubble mound breakwater has been derived utilising the general experience on this subject found in the bibliography and from the results of comprehensive series of model tests carried out at Danish Hydraulic Institute (DHI). The expression includes the important breakwater parameters (geometry of the breakwater profile) and the environmental parameters, and has been derived for applications with non-breaking waves in front of the structure. In research studies, model test series were carried out on pure rubble mound breakwater profiles with quarry rock as armour layer. Through results from projects carried out at DHI, the expression was extended to include different armour types and to describe the influence of a superstructure. The aim has been to set-up a reliable expression, which is simple, general and easy to use. Previously predictions of overtopping discharges have been based either on expressions including empirical constants for different shapes of the breakwater profile, on very complicated expressions or on diagrams giving the over topping discharges as function of the layout of the breakwater profile and the environmental conditions.