摘要

Wave transmission and overtopping around nearshore breakwaters can have significant influence on the transmitted wave parameters, which affects wave conditions and sediment transportation and becomes the focus of design in engineering. The objective of this paper is to present a simplified model to estimate these important wave parameters. This paper describes the incorporation of wave transmission and overtopping module into a wave model for multi-directional random wave transformation based on energy balance equation with the consideration of wave shoaling, refraction, diffraction, reflection and breaking. Wen's frequency spectrum and non-linear dispersion relation are also included in this model. The influence of wave parameters of transmitted waves through a smooth submerged breakwater has been considered in this model with an improved description of the transmitted wave spectrum of van der Meer et al. (2000) by Carevic et al. (2013). This improved wave model has been validated through available laboratory experiments. Then the verified model is applied to investigate the effect of wave transmission and overtopping on wave heights behind low-crested breakwaters in a project for nearshore area. Numerical calculations are carried out with and without consideration of the wave transmission and overtopping, and comparison of them indicates that there is a considerable difference in wave height and thus it is important to include wave transmission and overtopping in modelling nearshore wave field with the presence of low-crested breakwaters. Therefore, this model can provide a general estimate of the desired wave field parameters, which is adequate for engineers at the preliminary design stage of low-crested breakwaters.