Okinawa is well known for its distinctive red soil, which is highly susceptible to erosion during heavy rainfall. When sediment is washed into nearby coastal waters, it can significantly impact the surrounding marine environment, particularly the island’s sensitive coral reefs. To address this environmental challenge, the Okinawa local government implemented a Mechanically Stabilized Earth (MSE) retaining wall using Maccaferri’s Terramesh® System to provide long-term slope stability while maintaining natural water permeability.

Installed within a confined construction corridor, the 5-metre-high retaining wall with a steep 73° face maximised the available space while delivering the structural performance required. Reinforced with Paralink® 100 geogrids, the system offers reliable reinforcement, efficient drainage, and durability, making it well suited to Okinawa’s challenging ground conditions.

Project Challenges

Okinawa’s distinctive red soil is highly susceptible to erosion during heavy rainfall, causing sediment runoff that threatens the island’s fragile coral reef ecosystem. The retaining structure also had to be built within a narrow corridor, requiring a steep 5-metre-high, 73° wall to maximise available space while maintaining stability. In addition, the design called for a permeable retaining wall capable of managing groundwater effectively, making conventional concrete structures unsuitable for the project’s environmental and engineering requirements.

Maccaferri Solution

The project adopted the Terramesh® Mechanically Stabilized Earth (MSE) Wall, reinforced with Paralink® 100 geogrids, to deliver a durable and environmentally responsible retaining solution.

The Terramesh® system combines reinforced soil technology with a permeable gabion facing, allowing water to drain naturally while maintaining structural integrity. Its steep wall configuration made it ideal for the restricted site, reducing the construction footprint while achieving the required 73° wall face.

By controlling soil erosion and improving drainage performance, the solution helps minimise sediment runoff into surrounding coastal waters, supporting the long-term protection of Okinawa’s valuable coral reef environment.

Terramesh®

Terramesh® is a facia unit for flexible reinforced soil wall system that made of double-twisted steel wire mesh gabion box with integrated tail mesh acting as a secondary reinforcement. Steel wire mesh is coated with Polimac coating which is advanced polymeric coating developed to sustain the sever environmental conditions.

Paralink® 100

Paralink® 100 is a high-strength geogrid reinforcement designed to provide long-term tensile strength and stability within reinforced soil structures. Working together with the Terramesh® system, it enhances the overall performance of the retaining wall while accommodating ground movement and demanding site conditions.