Geosand

Pumping erosion is the result of train axle loads rippling along a railway track. The rapid sequential loading and unloading of rail sleepers caused by a moving train transmits a pulsating load to the ballast/sub-base interface. Where a track is built on a fine clay/silt sub-base, this pulsating load may cause the surface of the formation to liquefy when wet, and may subsequently be forced upwards into the ballast layer. This undesirable breakdown and movement of the clay/silt base layer has the potential to cause distortion of the whole track structure.

Traditional methods of remediation include a 100mm thick bed of sand is installed along the entirety of the track construction area at risk of pumping. Such an overzealous application of sand is expensive and labour intensive to install.

The Geosand solution for rail track applications

Geosand allows a particulate material, such as sand, to be contained within a geosynthetic structure thereby providing means for installing a consistent layer thickness over an undulating surface much easier. By ensuring that a known quantity of particulate material, such as sand, is installed per unit area of track-bed this allows a much thinner layer of sand to be applied than conventional methods, thereby reducing material costs. Further, the containment structure of geosand also allows the particulate material to be positioned and installed in a much quicker and efficient manner than installation methods associated with the prior art.