Track Foundation Stabilisation
Improving track foundation with Tensar geogrids
Laying railway track over weak formations and soft subgrade with a low bearing capacity leads to a low stiffness trackbed unable to support the ballast effectively – inevitably leading to ballast deformation and a breakdown in track geometry. Additional support can be achieved through 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 a significant 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 with Tensar geogrids, the sub-ballast can be reduced as much as a third for the same bearing capacity
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Lower construction costs: reducing excavation, soil disposal and imported sub-ballast fill can lead to significant savings
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Reduced carbon emissions: a significant reduction in aggregate thickness can realise major savings in CO2 emissions
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Longer maintenance cycles: with a better supported trackbed, the maintenance cycle can be extended
A proven solution
Since the early 1980’s, Tensar geogrids have been used by Rail Authorities across the world, as well as being the subject of extensive independent research.Trials have shown that Tensar technology can increase the bearing capacity of sub-ballast layers by a factor of 2 compared with the same unreinforced thickness.
Whatever your rail project, we can help
Tensar’s innovative technology has been used in rail projects worldwide, and 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 regularly run free workshops.