Wave Loads on Pile-Supported Decks Overhanging Armoured Slopes

Deck structures overhanging rubble mounds are commonly adopted solutions for quay walls for marine terminals in relatively deep water or in geotechnical complex conditions. The interaction of waves with relatively low-lying pile supported decks overhanging wave-absorbing slopes can lead to wave energy amplification and entrapment underneath the deck, which can therefore experience very intense dynamic loading, resulting in significant damage and even structural failure.

A physical model study has been carried out with the aim to explore the relative importance of key parameters and develop new formula for use in the estimation of wave slam forces for design purposes. Different combinations of water level/deck freeboards, wave heights and periods were tested using both regular (monochromatic) and irregular (random) waves. The results showed a relationship between the normalised vertical forces (F*) as a function of the normalised run-up clearance (R*). As expected, once a critical threshold between the freeboard and the run-up has been exceeded, the loads on the underside of the deck start to increase rapidly.