2023 Volume 79 Issue 18 Article ID: 23-18152
Few experimental studies have been conducted on the application of stone gabions as armor units on the sea side of a composite breakwater, leaving the stability and design of such coastal structures largely unclarified. In this study, a 1/40 scaled irregular wave experiment was performed using stone gabions as armor units. The dimensionless average slip amount D’, a value representing the average slip amount for each stone gabion model in the direction of the mound slope, was calculated. This value, when at 0.15, was considered as the significant wave height for design purposes, and was substituted into Hudson's formula, a designated mass calculation formula for a composite breakwater. As described above, Ns, the stability number is an index of stability performance, was calculated. Compared with Ns when filter units were used as armor units, Ns was found to be relatively large when d/h, the ratio of the water depth above the mound top edge to the water depth of in front of breakwaters, was 0.6 in some cases, but was comparable when d/h was 0.4. The findings from this study confirm the stability of armor units on the sea side of a composite breakwater, indicating no issues under the examined conditions.
