Hydrodynamic Stability of Gabion Box Reef Breakwaters

Abstract

Gabion-based coastal structures are being adopted frequently in recent times due to its energy dissipation characteristics and reduction in construction time. The coastal defense has become an essential aspect for maritime facilities and for the places prone to erosion. Reef breakwaters (also called Low crested structures) are seen to cause less environmental impact which makes them popular in recent past. The present investigation involves the study of hydrodynamic stability aspects of gabion-based reef breakwaters. Though these coastal protection structures are meant for wave attenuation, a study on the stability aspects of the structure to resist wave action is essential. This knowledge on the hydrodynamic stability is essential to come out with the design basis for construction of such coastal structures in a wave environment. This investigation on gabion-based reef breakwaters is performed using physical model tests with varying wave parameters and reef geometries. The study is aimed at fetching knowledge on the determination the weight of the gabions to resist the wave action by obtaining a relation between the weight of the gabion, geometrical parameters and to that of the wave parameters. This determination of the weight of the gabions to resist wave action is essential if gabion-based structures are deployed as low crested coastal structures or reef breakwaters. This paper is based on the experimental study conducted in the shallow water wave flume facility in the Department of Ocean Engineering, IIT Madras.