New 2D laboratory experiments on wave overtopping at vertical walls under impulsive and non-impulsive conditions

This paper describes 2D physical model study on wave overtopping at vertical coastal structures. Results of two experimental campaigns are presented, where different wave and geometrical parameters are considered. Wide ranges of relative water depth at the toe of the structure and relative crest freeboard are explored, considering two foreshore slopes in front of the vertical wall. Wave–wall interactions both for pulsating and impulsive regime are tested. The wave overtopping time series measurement allows to analyze not only mean overtopping discharges but also individual overtopping volumes. Single overtopping volumes distribution is investigated relating it to geometrical and hydraulic parameters. The present experimental analysis is coherent with the literature, in the already explored range of wave and geometrical parameters of the structure; moreover, it extends the previous findings, providing two main outcomes: (i) new mean wave overtopping measurements for a wider ranges of relative water depth and relative freeboards; (ii) new individual wave overtopping volumes measurements at vertical walls, specifically under impulsive conditions. New insights on the mean overtopping discharge and on the probability distribution of individual overtopping volumes are provided. • 2D physical model on wave overtopping at vertical wall, with horizontal and gentle sloping foreshore. • Results are analyzed both in term of mean overtopping discharge and individual overtopping events. • The experimental tests cover both non-impulsive and impulsive conditions. • New measurements of mean overtopping and individual overtopping volumes at vertical walls.