Overtopping of coastal structures caused by irregular waves
This thesis is an experimental investigation into the average rate of overtopping caused by irregular waves. A literature review is given which describes the previous research done in the field of overtopping. This research included a number of model studies using both regular and irregular waves. The literature review emphasises the dimensionless parameters which were developed by the various researchers in order to present their experimental results. The overtopping experiments were conducted in a 30m long, 0,75 m wide and 1,0 m deep wave flume equipped with an irregular wave generator. The flume was divided by two walls into three channels and the model structure was placed in the centre channel while the two side channels were used to measure the incident wave conditions. Irregular waves with a Jonswap spectrum were generated and the water which overtopped the model structure was collected in a calibrated tank located behind the structure. A wide range of wave conditions including waves which broke offshore of the structure, at the structure and beyond the structure were tested. The model structures tested were a 100 mm high vertical wall, a 200 mm high vertical wall and a 100 mm high wall with the seaward face inclined at 45°. It was found that the mechanism of overtopping was different for unbroken and broken waves. In order to model the kinematics of the water particles involved in the overtopping process, the concept of the total energy level or total head associated with the incoming waves was introduced.
Networked Digital Library of Theses and Dissertations