Variation of Pressure Distribution on Vertical/Caisson Breakwater with Toe Protection

A caisson/vertical breakwater along with the submerged toe protection was originally proposed by (Brebner and Donnelly (1962), and its design procedure and hydrodynamic performances were investigated by various researchers in the subsequent years. In this study, the variations of wave pressure distribution along with the submerged toe protection on the seaward side are analysed. The hydraulic model tests was conducted in a two- dimensional wave flume of 50.0m length,1.1 m depth and 0.71m width, at the National Institute of Technology Karnataka, Surathkal (NITK). The range of non-dimensional relative wave steepness (H_i/L- 0.008-0.052), relative water depth (d/L- 0.04-0.147) and relative wave height (H_i/d- 0.133-0.533) respectively. The wave pressure calculated with the applicability of the empirical formula suggested by sainflou (1928) and Goda (1985) are compared with the test results. Normally it’s expected that the wave pressure on the vertical / caisson structures reduces when the cross-section of the protecting structure (submerged toe) varies for given water depth. And it’s found that the wave pressure increasing with increases in wave height, this is due to the fact that larger waves have larger wave crest. The quantity of water under wave crest is more and hence larger waves exert more pressure on the model. And its smaller when the caisson/vertical breakwater is provided with toe protection.