Forces due to Waves on Submerged Structures

Existing theories on wave forces on large submerged structures are reviewed. The equations regarding wave forces and moments on piles do not apply because inertial forces are predominant on a submerged structure which has a principle horizontal dimension equal or larger than the vertical dimension. Several models of simple geometric structures were installed in a two-dimensional laboratory wave tank. The magnitude of the vertical and horizontal loads on the structure by the wave action were determined experimentally. Values of coefficient of inertia were obtained for experimental data. Results of data wer plotted in dimensionless form to provide a correlation between ratios of wave length to water depth, wave height to wave length, and dimensionless force for a number of different shapes of structures. Measurements were also obtained for one of the models of forces due to irregular, wind-generated waves. Comparison between forces caused by regular waves and irregular waves was made. It is concluded that forces due to waves, particularly due to irregular waves generated by wind are highly variable, but results presented may be sufficient for preliminary designs.