| Summary: | There is no guidance available for either mean or wave-by-wave overtopping discharges over vertical seawalls subject to oblique and impulsive wave attack. Impulsive wave attack (i.e. waves break onto the structure) may lead to substantially higher overtopping volumes than pulsating wave attach and can arise at relatively low water levels. Mean and wave-by-wave overtopping discharges represent important quantities in the design of coastal structures. The not only affect the structural safety and determine the capacity of the drainage system behind the structure, but also pose a hazard to communications, buildings, and members of the public. Previous work has shown that impulsive overtopping can substantially increase overtopping volumes and velocities, thus underlining the importance of robust prediction tools. This PhD thesis describes experiments and analysis to provide design guidance in wave overtopping of vertical seawalls under oblique and impulsive wave attach. The guidance extends existing design tools for wave overtopping which cover both wave conditions under oblique wave attack. Special attention is given to the transition from impulsive to reflecting wave conditions, which goes along with a significant reduction in overtopping towards higher obliquities. For moderate obliquities (15° and 30°) a new intermediate wave condition is defined as the “impact-like” condition, which – in terms of overtopping – has still to be treated as impulsive. Contrary to a few previous investigations on sloping walls, no increase in overtopping could be found at small obliquities (15°). Spatial variability, however, could be measured along the seawall and has been considered in the design guidance offered in this thesis.
|
|---|
