Wave pressures and forces on slotted vertical wave barriers

Abstract

Vertical slotted barriers are cost effective energy-dissipating structures. The design of such barriers requires an accurate estimation of dynamic pressures and resulting wave forces. Herein, a physical model study is carried out to assess the wave forces acting on a single and twin wave barriers of various porosities under a wide range of wave conditions. The study provides explicit data on how dynamic pressures vary vertically from the seabed to the still water surface and on the resulting forces, both seaward and shoreward. In particular, the experimental results indicate that porosity affects dynamic pressures significantly especially near the free surface, but less so closer to the seabed. Further, resultant horizontal wave forces seaward are 20–25% less than shoreward forces. Forces on the front panel in the twin wave barrier cases are 20–25% more than those on a single porous wall while the forces on the rear or second barrier is always 20–25% less than the single wave-barrier case under identical test conditions. These and other results presented in the study can be useful in designing wave dissipaters, especially for inner harbors and vertical sea walls.