Hydrodynamic characteristics of a vertical wall with an immersed horizontal plate subjected to regular and random waves

Experimental investigations on wave transmission, reflection, dissipation, forces, moments, run-up, and rundown were conducted on a vertical wall (VW) and on a vertical wall fixed with an immersed horizontal plate (VWHP) for a wide range of regular and random waves. It was found that wave reflection can be reduced by 25%-35% using a VWHP (with plate length equal to water depth with a submergence of 28.6% of the water depth) and that dissipation can be increased by 25%-35%. The normalized significant inline wave force on the VWHP can be reduced from 0.8 to 0.1 for 0.1 < d/L-p <0.5. The global inline wave force on the VWHP can be reduced by >50% for d/L-p > 0.3, when compared to VW, which is beneficial in the design of horizontal sliding. The vertical wave forces on the VWHP were significantly higher and increased significantly for lower values of d/L-p, especially for d/L-p = 0.1. The wave-induced moment is 10-20% less for the VWHP compared to that for the VW, which is also useful for the design against overturning, especially if the results are used for the design of caissons with D/L > 1, where D is the width of the caisson.