Armor Damage of Overtopped Mound Breakwaters in Depth-Limited Breaking Wave Conditions

Abstract

Armor damage due to wave attack is the principal failure mode to be considered when designing conventional mound breakwaters. Armor layers of mound breakwaters are typically designed using formulas in the literature for non-overtopped mound breakwaters in non-breaking wave conditions, although overtopped mound breakwaters in the depth-induced breaking wave zone are common design conditions. In this study, 2D physical tests with an armor slope H/V = 3/2 are analyzed in order to better describe the hydraulic stability of overtopped mound breakwaters with double-layer rock, double-layer randomly-place cube and single-layer Cubipod® armors in depth-limited breaking wave conditions. Hydraulic stability formulas are derived for each armor section (front slope, crest and rear slope) and each armor layer. The front slope of overtopped double-layer rock structures is more stable than the front slope of non-overtopped mound breakwaters in breaking wave conditions. When wave attack increases, armor damage appears first on the front slope, later on the crest and, finally, on the rear side. However, once the damage begins on the crest and rear side, the progression is much faster than on the front slope, because more wave energy is dissipated through the armored crest and rear side.

Review on Fixed and Floating Offshore Structures. Part II: Sustainable Design Approaches and Project Management

“…For breakwater and wave energy devices, they require shallower water depths. However, these devices have been able to operate under a diverse range of wave environments as seen in the diverse range of technologies, and devices such as the single column and multi-column wave energy converters (WECs) [164][165][166][167][168][169][170][171][172][173].…”

“…Hence, a load analysis considering the structure's dynamic activity is required for proper analysis of such platforms. Wave loads are also used in designing breakwater devices and wave energy converters (WECs) [164][165][166][167][168][169][170][171][172][173]. Figure A5 in Appendix A shows the global annual wave energy distribution.…”

“…The majority of offshore platforms are built in shipyards using enormous steel or in-situ using concrete, as is the case with gravity-based structures. These fixed and floating offshore constructions are mostly utilised for energy generating or oil production, while some are used as breakwater devices and wave-energy converters (WECs) [164][165][166][167][168][169][170][171][172][173]. Offshore platforms can be small or massive, depending on the functionality.…”

Armor Damage On Groins Under Ship Wave Attack Using Field Data

“…Physical model tests on the hydraulic stability of the armor layer of rubble mound breakwaters under sea wave attack are common practice in scientific literature (e.g. : Mares-Nasarre et al, 2021, 2022. However, physical experiments on groyne stability attacked by long-period ship waves are relatively novel and, thus, data from laboratory is scarce and limited.…”