WAVE OVERTOPPING CHARACTERISTICS FOR A DOUBLE VERTICAL WALL AND THE EFFECT OF PARAPETS

Abstract

The mean wave overtopping discharge and extreme overtopping volumes were assessed for a double vertical wall solution, including the combined effect of the mutual distance and effect of parapets, also known as wave return walls or bullnoses. New empirical functions were derived for predicting the mean overtopping discharge and maximum overtopping volumes applicable for this design case. This study demonstrates the importance of analyzing the statistical characteristics of extreme overtopping volumes, especially for cases with low number of overtopping waves and steep volume distributions. It is argued that derivation of these statistics is essential for design of coastal structures and required drainage system at the hinterland. The analysis has shown that performing repetition tests is valuable, especially with cases of low number of overtopping waves. Generating more data allows for the derivation of more reliable statistics and in turn enables better quantification of the associated uncertainties. Statistical parameters of wave overtopping volumes showed that it provides critical design input for drainage and enable the generation of synthetic overtopping events with realistic distributions of wave overtopping volumes.