Stability Study on a Submerged Breakwater: a Physical Model Study

Submerged breakwater is an off shore breakwater, with its crest at or below the SWL, used for creation of protected area of water or for protection of coastal structures and beaches from damage of erosion caused by wave action. Reef breakwaters are coast parallel structures built with an objective of reducing the wave action on the beach by forcing wave breaking over the reef. The present work involves the experimental study on submerged breakwater made of concrete cube armour of varying sizes. A stable trapezoidal submerges breakwater having a slope of 1V:1.75H with a crest width (B) of 0.1m and height (h) of 0.25m is constructed, with homogenous pile of concrete cubes. Two such reef models are designed with concrete cubes weighing 45g and 50g as given by various design criteria. The models are tested in water depth of 0.4m with varying wave heights (0.1m to 0.16m) and wave periods (1.5s to 2s). During the investigation the reduction in crest height, wave incident and transmission over submerged breakwater are observed and the stability parameters are analysed and studies.