Vertical Wave-in-Deck Loading and Pressure Distribution on Fixed Horizontal Decks of Offshore Platforms

The risk assessment of wave-in-deck loading on fixed platform decks requires accurate prediction of both global and local loading. In this paper, the vertical loading generated on the bottom plate of a rigidly mounted box-shaped structure due to unidirectional regular waves is computed by means of two approaches. The first is a component-based approach based on Kaplan's method and the second is a computational fluid dynamics (CFD) approach based on the volume of fluid (VOF) method implemented in the commercial CFD code FLUENT. Different parameters including wave steepness and air gap are tested. The obtained results are validated against tank experiments. The study revealed that when the wave-in-deck events are measured globally and locally the load magnitude, its duration as well as its distribution is better evaluated and the uncertainty involved with these impulsive loads can be reduced. It was found that in many cases Kaplan's method underestimates the magnitude of the force in the upward direction. CFD force predictions were found to be in better agreement with the measured forces.