Midscale Physical Model Validation for Scour at Coastal Structures: Final Report

A 1-to-7.5 scale (midscale) movable-bed physical model was used to validate model scaling criteria selected as most appropriate for turbulence-dominated erosion of sediment by waves. Two-dimensional flume tests successfully reproduced profile evolution observed in prototype-scale wave flume tests conducted under both regular and irregular wave conditions. For the case of regular waves, a sloping concrete revetment was exposed, thus validating the scaling guidance for use in studying scour at coastal structures. Variations in experimental parameters were systematically examined. Comparisons between regular wave and irregular wave profile evolution indicated that best correspondence is achieved if the significant wave height equals the monochromatic wave height, although irregular wave profile evolution takes about twice as long. The impacts of a vertical seawall on profile change are briefly examined.