WAVE BREAKING OVER SUBMERGED HORIZONTAL PLATE

The inceptive condition for wave breaking over a submerged horizontal plate is proposed. The incident wave parameter I = gH(o)/C-h(2), which reduces to the relative wave height for long waves and is proportiona l to the wave steepness for deepwater waves, is used as the breaking i ndex. Waves break over the plate when I is greater than a critical val ue I-c, which depends on the ratio of the wave celerity over the plate to that of the incident wave and also on the relative length of the p late to the incident wavelength. The establishment of the breaking inc eptive condition is based on an empirical formula for partial standing waves breaking in uniform water depth. To determine the relation betw een the local waves over the plate and the incident wave, linear analy sis is employed, and a modification is then made to take into account the nonlinear effect. A laboratory experiment is carried out to verify the semiempirically established breaking condition, and satisfactory agreement between the semiempirical prediction and the experimental ob servation is obtained.