Protection of Shoreline by Using Partial Revetment Structure under Regular and Irregular Waves

Abstract

In this paper, results obtained from an experimental investigation conducted to determine wave-induced geometric characteristics of shorelines protected by partial revetment structure are presented. The experiments were performed with both regular and irregular waves. The beach sand used in this study had a mean diameter of 0.35 millimeter and a specific gravity of 2.63. The beach had an initial slope of 1 : 5 and was protected by the partial revetment structure. For this purpose, the armor units, mean diameters and specific gravities of which were varied in the range 8.5–67.95 millimeters and 1.81–2.77, respectively, were placed on the wave-breaking area. Different wave groups were generated over an initially flat, partially protected beach, and a number of geometric characteristics of equilibrium beach profiles was determined. Moreover, the static damage of the armor layer was obtained for all test groups. The results of this experimental study were evaluated, and empirical expressions based on the results were formulated to define geometric parameters of equilibrium profile under pure regular waves, pure irregular waves, and regular-irregular waves. The findings showed that the partial revetment structure decreases shore erosion on average 65–70%. Because the sand of the unprotected area spreads over the armor layer, this revetment type does not disturb the beauty of the area and its aesthetics. Moreover, it is a low-cost structure, because the armor layer was placed only within the wave-breaking area, not across the entire slope.