Wave forces and dynamic pressures on slotted vertical wave barriers with an impermeable wall in random wave fields

Abstract The use of vertical slotted barriers can be a cost effective solution for wave energy dissipation when sloped rubble structures are not desirable. For a cost-effective design of such barriers, an accurate estimation of dynamic pressures and wave forces is needed. A well-planned physical model study is carried out for this purpose on single and twin wave barriers of various porosities under a wide range of random wave conditions. This study provides explicit data for the vertical variation of the dynamic pressures from the seabed to the still water surface and for the resulting forces, both seaward and shoreward. The experimental results indicate that the porosity affects the dynamic pressures significantly, especially near the free surface, but less so closer to the seabed. Further, the resultant seaward horizontal wave forces are 20% to 25% less than the shoreward forces. Forces on the front panel in the twin wave barrier cases are 20% to 25% greater than those on a single porous wall, whereas the forces on the rear or second barrier are always 20% to 25% less than those on the single wave barrier under identical test conditions. These and other results presented in the study can be used for designing wave dissipaters, especially for inner harbors and vertical sea walls.