Wave forces on cubical armour units on submerged and low-crested breakwaters.

摘要

Dynamic forces on a cubical shaped armour unit produced by breaking waves were investigated experimentally in a model of submerged and low-crested breakwaters. Measurements were made along the surface of the breakwater to determine the most critical location of the armour unit. The measurements of the force were conducted using a specially designed dynamometer to enable a simultaneous measurement of the tangential and normal force components acting on a cubical armour unit. Two dynamometers were used to study the simultaneous forces induced by breaking waves on two cubical armour units for selected variables including water depth, the height and period of the wave, the location and orientation of the units, and the slope of the breakwater. Analysis were made of the transmitted, reflected, and dissipated wave energy. The transmission and reflection coefficients were presented in relation to the submergence of the breakwater. A modified Morison equation was introduced to describe the longitudinal forces on an armour unit. The improved Morison equation was suggested by adding impact force term due to wave breaking to the Morison equation. Envelopes of maximum forces on the armour unit was developed for units placed anywhere along the surface of the breakwater. The envelopes of the forces were presented for the forward, backward, upward, and downward forces on the unit. The stability of the armour unit was analyzed using the dynamic force data. The stability analysis was made for the unit placements at the seaward and landward edges of the crest. The stability of the unit was investigated for both sliding and overturning caused by the tangential and normal force components, and the spinning moment about the centre of mass of the cubical armour unit.Dept. of Civil and Environmental Engineering. Paper copy at Leddy Library: Theses u26 Major Papers - Basement, West Bldg. / Call Number: Thesis1997 .P72. Source: Dissertation Abstracts International, Volume: 59-08, Section: B, page: 4308. Adviser: J. A. McCorquodale. Thesis (Ph.D.)--University of Windsor (Canada), 1997.