Experimental investigation of the hydrodynamic effects of breaking waves on monopiles in model scale.

In the present paper, a hydrodynamic model test of the monopile of the NREL 5-MW offshore wind turbine is carried out, and relevant data are presented. The effects of highly non-linear breaking waves were measured in terms of the wave run-up and wave loads around the offshore wind turbine monopile. The wave run-up and the interaction between the non-linear wave load and the monopile were analyzed at different positions around the monopile. The wave run-up around the monopile for the wave breaking conditions is quantified approximately twice the amplitude of the incident wave height. For specific examined wave breaking conditions, the wave height in front of the monopile is lower than behind the monopile. Empirical calculations are also used to verify the experimental results. The wave breaking forces calculated using the empirical formulas are conservative compared with the experimental data, although the experimentally measured maximum wave breaking force is smaller than that calculated one using relevant analytical methods. The present paper gives an insight into the design of monopile foundations for specific wave breaking conditions. [ABSTRACT FROM AUTHOR]