Track Foundation Stabilisation
Improving track foundation thanks to Tensar geogrids
Laying railway track over weak formations and soft subgrade with a low bearing capacity leads to a low stiffness trackbed, which is unable to support the ballast effectively. This inevitably leads to ballast deformation and a breakdown in track geometry. Further support can result from chemical stabilisation or deep excavation followed by a thick granular sub-layer, although both these methods are time-consuming and expensive.
How Tensar geogrids can help
With geogrids, the granular material in the sub-ballast layer partially penetrates and projects through the apertures to create a strong and positive interlock, providing additional support for the trackbed. In fact, Tensar geogrid reinforcement can allow for a substantial reduction of the sub-ballast layer thickness, for the same bearing capacity.
The benefits
Adding a mechanically stabilised layer at sub-ballast level has several advantages:
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Reduced layer thickness: tests have shown that thanks to Tensar geogrids, the sub-ballast can be reduced as much as one third for equal bearing capacity
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Lower construction costs: reducing excavation, soil disposal and imported sub-ballast fill can result in substantial savings
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Reduced carbon emissions: a substantial reduction in aggregate thickness can realise significant CO2 emissions savings
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Longer maintenance cycles: as the trackbed has better support, the maintenance cycle can be extended
A proven solution
Since the early 1980’s, Tensar geogrids have been used by Rail Authorities around the globe, as well as being subject to extensive independent research. Trials have shown that Tensar Technology can increase the bearing capacity of sub-ballast layers by a factor of 2 when compared to the same thickness which is unreinforced.
Whatever your rail project, we can help
As Tensar’s innovative technology has been used in rail projects worldwide, a full range of case studies and brochures is available. We also offer full technical support including expert advice, specifications, drawings, certified designs and details of pricing, and we run free workshops regularly.