Influence of Permeability and Wave Steepness on Wave Forces on Crown Walls for Non-Breaking Waves

This study investigates how structural permeability and wave steepness affect wave-induced loads on crown walls in rubble mound breakwaters. Evaluating prediction models by Nørgaard et al. (2013) and Molines et al. (2018) against measurements from 591 new physical model tests at Aalborg University revealed that the permeability has minimal impact on the horizontal forces, while influencing significantly the vertical loads and the overturning moment. Nørgaard et al. (2013) and Molines et al. (2018) formulae provide similar agreement against the experimental data for horizontal forces. The Nørgaard et al. (2013) formula is more accurate for predicting base pressures and vertical forces. Both prediction methods show varying accuracy depending on the conditions. The experimental data shows significantly less variation in repetition tests than predicted by the formulae, indicating that further improvements of the formulae can be achieved in future work.