Gabion Coastal Protection for Shoreline Stabilization and Marine Erosion Control

Gabion coastal protection for shoreline stabilization, cliff toe protection, and dune restoration against wave action. Common specifications involve high-durability, PVC-coated or Galfan-treated double-twisted hexagonal steel wire mesh to withstand saline corrosion and abrasion. Typical units are 2.0m x 1.0m x 1.0m, while thinner Reno mattresses (0.17m–0.3m) are used for revetments. The mesh size is usually 8x10 cm, filled with hard, non-degradable rock (100–250 mm) that exceeds the mesh aperture. This porous design effectively manages hydrostatic pressure and promotes sediment entrapment, which often leads to natural revegetation.

Gabion Coastal Protection for Shoreline Stabilisation and Erosion Control

This gabion coastal protection faced repeated wave action, periodic storm surges, and gradual soil loss along the exposed edge of the coastline. A gabion coastal protection system was selected because it combined mass stability, permeability, and flexible structural performance.

Project Location

The project was completed along an exposed coastal section near a service road and pedestrian access area. The shoreline had shown continuous erosion during high tide cycles and storm events. Parts of the bank had receded, and the lower slope was vulnerable to scour and washout.

Gabion Coastal Protection Solution

A stepped gabion coastal protection wall was designed along the eroded shoreline. The system used double twisted hexagonal gabion baskets filled with hard angular rock. The gabion units formed a stable revetment structure that protected the bank surface, reduced scour, and allowed water to pass through the stone fill.

Main Specifications

• Gabion box size: 2 m x 1 m x 1 m
• Mesh type: Double twisted hexagonal wire mesh
• Mesh opening: 80 x 100 mm
• Mesh wire diameter: 2.7 mm
• Selvedge wire diameter: 3.4 mm
• Lacing wire diameter: 2.2 mm
• Wire coating: Galfan or heavy galvanised with PVC coating
• Structure length: 45 m
• Structure height: 3 m
• Foundation type: Embedded toe section with stone base
• Fill material: Angular rock, 100–250 mm

Installation Process

The construction team first cleared loose soil and unstable material from the shoreline edge. A foundation trench was then prepared at the toe of the slope to support the first row of gabion baskets. Where required, a geotextile layer was placed behind the gabions to reduce soil migration while maintaining drainage. The gabion baskets were unfolded, assembled, and tied together with lacing wire to form a continuous structure. Each basket was filled in layers with selected angular stone, and internal bracing wires were installed to maintain panel alignment. After filling, the lids were closed and secured. Additional tiers were stacked in a stepped arrangement to match the shoreline profile and improve overall stability.

Project Results

The gabion coastal protection system reduced shoreline erosion and stabilised the exposed bank section. After installation, the site showed improved resistance to wave wash and surface scour. Water drained naturally through the stone-filled structure, which reduced pressure build-up behind the wall. The stepped gabion face also helped absorb and disperse wave energy. The client achieved a durable shoreline protection system with lower maintenance requirements and simpler construction compared with a rigid concrete alternative.