Challenge

GeoGrow installed its Rootlok vegetated retaining wall system as a facing solution for an existing sheet pile wall. The company was selected due to its expertise in green solutions and ability to tailor solutions to suit the surrounding landscape and ecological considerations. 

Solution

The project was executed in two phases to accommodate the installation of the capping beam for the existing sheet piles before completing the Rootlok wall.

The first phase involved construction from ground level up to approximately 1.6m, while the second phase was completed on scaffolding from approximately 1.6m to the final drawing levels.

Total wall area: 128m2 including footings; 2.4m max height.

Construction details

Threaded bars with base plates were utilised, welded at approximately 420mm vertical intervals and 1.5m horizontals onto the existing sheet piles by a subcontractor. The Rootlok elements were then built around these protruding pins. Upon installation of Rootlok, the pins were cut back and mesh was secured to the front face of the Rootlok wall. To secure the mesh, 100 x 100mm steel plates were positioned over each protruding pin, with an M12 nut torqued onto the threaded bar to hold the plate and mesh in place. Dome nuts were then used to cap off the bars, eliminating any exposed sharp edges for safety purposes.

Seed specification and environmental considerations

The choice of a wildflower mix for pre-seeding the Rootlok bags was deliberate, aiming to integrate the Rootlok facing solution seamlessly into the surrounding landscape. This approach was particularly suited to the area's public open space, featuring footpaths, hedgerows and significant wildlife presence.

Outcome

Overall, the project addressed the need for a secure facing solution, and also prioritised environmental compatibility and aesthetic harmony with the surrounding landscape.