Hydrodynamic characteristics of seaside perforated semicircular breakwaters due to random waves

The semicircular breakwater (SBW) is a composite breakwater consisting of a semicircular caisson resting on a rubble mound. The SBW function as a barrier dissipates the incident wave energy and creates tranquility on its leeside. The dynamic pressures due to random waves exerted on seaside perforated SBWs with 7, 11, and 17% of its exposed surface area with perforations were measured. The measured pressures are compared with experimental results of SBW without perforations. In addition, the forces exerted on the caisson alone are measured. The reflection coefficient, runup characteristics, measured total forces, and dynamic pressures in a dimensionless form are presented as a function of relative water depth. The tests were conducted for surface piercing conditions. The effect of the water depth, perforations, and rubble mound height on the above stated variables are brought out, the details of which are reported in this technical note. © 2008 ASCE.