Model Tests of Coastal Protective Structures in USSR

A variety of designs of underwater breakwaters, their process of wave destruction and dynamically balanced shore profile development were developed in extensive laboratory tests and comparative observations in nature, by the Soviet Institute of Engineers of the Maritime Fleet in Odessa. Twenty types of structures, under the influence of a variety of incidence waves and three stages of immersion, were tested and statistically evaluated as to their costal protective efficiency. Empirical equation and graph formulate the relationship of incidence wave parameters and breakwater dimensions for planned structures. Breakwaters with vertical surfaces generate turbulent destruction of waves with limited passage of sediment, whereas with both sides sloped 1 : 1 structures destroy the waves calmly and transfer one and a half times more beach material. In both cases decrease of the crest immersion produces a considerable decrease in the sediment transport capacity. Maximum disintegration occurs on the upper part of the vertical or sloped breakwater. Curved surface structures show considerably less abrasive effect, appearing only at the lower half of the front surface.