Optimization of stepped revetment configuration on minimizing wave run-up and overtopping

Abstract

A stepped revetment has proven to be able to attenuate wave run-up height and wave overtopping discharge more effectively than a dike or a smooth-slope revetment does. However, the investigation into the optimal design of a stepped revetment, tailored to different wave and coastal conditions, is notably lacking. This paper introduces a computational model developed from the non-linear shallow water equations and the Genetic Algorithm. The aim is to optimize the width of a stepped revetment's step and crest, considering wave run-up and overtopping as key parameters. Multiple benchmark tests were conducted to validate the model's accuracy in estimating wave run-up and overtopping for specific setups. The results demonstrate a strong correlation between the numerical findings and experimental data. The Genetic Algorithm was then employed to predict the optimal step width for minimizing wave run-up height and determining the optimal step and crest widths to reduce wave overtopping discharge to an acceptable level. The findings reveal that for a gently sloping stepped revetment, the optimal step widths, based on wave run-up, remain relatively consistent across different wave heights. In contrast, when optimizing for wave overtopping, the optimal step width tends to fluctuate in most cases, although it shows some consistency in certain scenarios.