Numerical and laboratory analysis of post-overtopping wave impacts on a storm wall for a dike-promenade structure

The problem of predicting the wave impact forces on walls and buildings, located at the crest of coastal defence structures with a smooth dike and a nearly horizontal promenade, is considered in this paper, using dedicated numerical computations and by re-analysis of available experimental data. The limit of previous studies on this important engineering problem, is that the geometries of the coastal defences structures considered are all very similar. Design methods (i.e. prediction formulae for the wave forces on the wall) are therefore developed within the specific ranges of wave and structural geometrical parameters considered in the experimental campaigns. In this paper, to partially overcome this limitation, the numerical model IH2VOF is applied to study the wave impacts on the specific structural layout introduced. First, validation is provided by means of comparison with available, mid scale, physical laboratory tests. Then, the model is applied to carry out parametric tests, to investigate the dependency of the phenomenon under much wider variations of the wave (mainly concentrating on the wave period) and structural (i.e. the length of the promenade, the height of the wall, the water depth at the toe) parameters than those considered so far. Finally, on the basis of the available experimental and numerical datasets a new empirical design formula is developed and presented.