Three-dimensional Nonlinear Wave Groups interacting with an Upright Breakwater

Nonlinear wave forces exerted on a vertical breakwater, due to short-crested (3D) wave groups, when an exceptionally high wave crest occurs, are investigated. The analytical investigations are based on a closed form solution for the reflection of short-crested wave groups, whose derivation is shown in the paper. It is obtained that the effects of non-linearity strongly affect the linear processes of both wave pressures and wave forces. In particular, a very important result is the occurrence of double positive peaks in the wave force process. Beneath the highest wave crest a local minimum of the wave force is observed with the formation of two maxima for each wave crest impact.