RUBBLE MOUND BREAKWATER STABILITY UNDER OBLIQUE WAVES: AND EXPERIMENTAL STUDY

A series of model tests was carried out in a wave basin at LNH to quantify the effect of long-crested, oblique waves on rubble mound breakwaters. Four types of armouring units (quarry stone, Antifer cube, tetrapod and ACCROPODE®) were tested, under six angles of wave attack (0°, 15°, 30°, 45°, 60°, and 75°). Overtopping, toe berm and main armour stability were studied as functions of wave obliquity. A method is proposed to reduced the results obtained under oblique waves to those obtained under normal waves, allowing thus for the use of formulae derived under normal waves for the design of a breakwater under oblique wave attack.