Nonlinear wave amplification in front of reflective structures

For the design of marine and coastal structures subject to nonlinear waves in deep to shallow water, it is crucial to take into account both wave/structure and wave/wave interactions. A critical phenomenon involving large wave amplifications on the weather side of reflective structures has been recently observed during experimental campaigns. It appears for a wide range of wavelengths, when compared to the size of the structure, and it is directly related to third order interactions in the wave steepness. This induces high free surface elevations, known as 'run-ups', associated with high local loads that can damage the structure. In this paper, we pursue theoretical and numerical calculations using two approaches: a steady-state spectral solution and time-domain simulations using a high-order Boussinesq model. Cases involving normal and oblique wave interaction with a vertical rigid plate are investigated.