Experimental study of wave forces on rubble mound breakwater crown walls

Abstract

This paper has two main objectives: (1) to describe the experimental work carried out in order to verify the theoretical method from Martin (1995) for the calculation of wave forces on crown walls and (2) to show some results from field and lab measurements and compare these data to calculations from several analytical methods. The Principe de Asturias Breakwater at Port of Gijon has been taken as the reference structure in this study. The experimental work (prototype and scale models) has been carried out over the same cross section, corresponding to this breakwater. Three scales have been used here: scale 1:1 (prototype measurements), scale 1:18..4 (tests done at Laboratorio de Ingenieria Maritima, UPC, Barcelona) and scale 1 :90 (tests done at Laboratorio de Ingenierfa Oceanogratica, Universidad de Cantabria). Therefore, data from the same phenomena in three different scales are available, which will provide the basis to analyse scale effects in the lab. The main part of the experimental work was carried out from 1995 to 1998 .. Due to the large costs of such a long experimental project, several organisations (referred in the acknowledgements section) were asked for financial support to the study. This is a good example of long-term project which was possible by the joint effort of, several institutions (public and private) within the European Research Framework. In the paper, forces from the tests are compared to calculations done from the method proposed by Martin (1995). The comparison shows good agreement between the calculations and the measurements from the lab, and not-so-good agreement to prototype data. From these results, it can be stated that the method is working well as it was developed from lab data From this study, it can be stated that differences to prototype forces are due to scale effects between lab and prototype measurements.