Geogrids and Geotextiles for Hexham Multi Rail Lines

Project Snapshot

The Hexham Relief Roads Project involves the design & construction of additional train lines (known as relief roads) for the Hunter Valley Coal industry in NSW.

In total, five new train lines are being constructed at a length of approximately two kilometres for each line. When completed these additional lines will help to ease congestion for coal trains travelling to and from the Newcastle Port Coal Terminal near the existing Up Coal line at Hexham.

This $163 million project is an initiative of the Australian Rail Track Corporation (ARTC) and is designed and constructed by the Upper Hunter Valley Alliance, consisting of several Tier 1 contractors.

The Challenges

The Hexham Relief Roads project is being constructed in challenging swamp and floodplain conditions. Preparing the ground for heavy coal-laden trains is a key step in the project’s success: once completed, an additional 10 million tonnes of coal per annum is forecast to travel through the area.

Our Solution

Global Synthetics was awarded the supply of geosynthetics for this project after successfully demonstrating that the products offered adequately met the design specifications.

This was achieved with Global Synthetics providing comprehensive technical data, testing and real proven project performance case histories on each of the products.

The design of the rail platforms consisted of three geosynthetics at the base of the platform known as the formation layer. First to be placed was a non-woven geotextile which acted as a suitable separation layer between the subgrade and newly placed quality materials. Above this was geogrid, followed by half a metre of rock fill, then a second layer of geogrid, followed by further rock fill placed until the design height was met.

Global Synthetics supplied a unique geogrid called Secugrid® 30/30Q1 LA as the reinforcement geogrid. Secugrid® 30/30Q1 LA has large aperture dimensions (71x71mm). This type of large aperture geogrid is generally used in rail platforms and embankment construction when large ballast is required. Secugrid® 30/30Q1 LA is made from high-strength polypropylene with a high modulus and is supplied in wide-width rolls to reduce wastage.

In total over 200,000m2 of Secugrid® 30/30Q1 LA has been utilised in the construction process. In conjunction with the Secugrid®, Global Synthetics also supplied Geofirma® nonwoven geotextile for separation and filtration.