Glenugie Upgrade, Grafton NSW

Project Snapshot

This project just south of Grafton involved turning an existing length of the Pacific Highway into a separated dual carriageway as part of the larger works programme for the overall improvement of the highway between Sydney and Brisbane.

Integral to the project was the need to ensure successful treatment of the drains, channels and culverts on the project to minimise scour and protect structures.

The original tender requirement was for a combination of rock mattresses, rock rip-rap, concrete lining and an erosion control turf reinforcement mat (TRM) for specific treatment approaches in the drainage structures.

Our Solution

Approximately 10,000m2 of a competitor TRM product was specified in the original tender documents, however Global Synthetics was able to provide an alternative with Landlok® 450 TRM.

This product demonstrated improved tensile resistance and enhanced UV resistance. Our team was also able to provide the client with substantial information on the proven performance of the product in a range of extreme hydraulic conditions.

Landlok® 450 is a product that has full testing and design software for use. For the Glenugie Upgrade Alliance Project, traditional rock and concrete structures were able to be replaced under given conditions of 5% maximum grade allowance.

About Landlok Turf Reinforcement Mat

Landlok® 450 is a synthetic turf reinforcement mat that provides positive reinforcement to grasses, prevents scour and allows vegetated drains to withstand hydraulic conditions that may normally be specified in traditional rock protection and concrete lining treatments.

The drain is shaped and prepared, the Landlok® 450 is pinned into position over previously seeded areas, a light soil covering is placed over the Landlok® 450 and grasses are allowed to germinate through the product.

Significant shear stresses can be imposed on the composite system, well in excess of the conditions that traditional grass-lined channels can withstand.

The Results

The contractor has continued to be very sympathetic in their environmental considerations on this project. One example was the use of indigenous local grass seeds, in conjunction with the Landlok®450 channel treatments and the wider revegetation treatments on this site.

This environmentally sensitive approach will ensure the maintenance of pre-existing environmental conditions long after the contractor has completed the project.

Significant cost savings have been achieved by the use of Landlok® 450 over more traditional treatments of scour protection, while maintaining the focus on environmental protection. During the construction of the project to date, there have been a number of extreme rainfall events, with completed Landlok® 450 channels performing exceptionally well under such conditions.

The success and the confidence that the contractor gained in the use of the Landlok® 450 TRM product has meant that over 30,000m2 was installed throughout the duration of the project.