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Geocomposites

Railway Track Bed

Geosynthetics play a major role in extending the maintenance interval for track ballast. Depending on the nature of the subgrade, geocomposites are deployed to:

  • prevent pumping of subgrade fines
  • control seepage and run-off
  • stabilise a subgrade to improve bearing capacity and maintain track alignment
Image showing Railway track bed application
Diagram showing a Protexia geocomposite drain

A Protexia geocomposite drain - drainage core with a robust geotextile filter on either side - replaces sand separating a ballast from a stable subgrade.

Diagram showing a Protexia geocomposite drain

A geogrid may be introduced as a third component of the geocomposite to stabalise a poor subgrade and improve its bearing capacity.

Rail Rig

GEOfabrics manufactures products on behalf of Aqua Geocomposites for track bed applications in the UK:

Protexia RK2 - a filter/geonet/filter composite - is marketed in the UK by Aqua as TED2

Permanent Way Information

More information

Rail Rig

image
  • 4.5m x 1.8m x 0.4m subgrade
  • Half-width sleeper
  • Three PC-driven ram actuators
  • Up to 120kN axle loads
  • Up to 12Hz application of rams
  • 1M cycles (6 day test duration) = 5 real-time years

With Department of Trade support, a testing rig has been designed and installed at GEOfabrics' laboratories to further develop and refine the performance of geotextiles and geocomposites beneath ballast.

The Company's products for track ballast applications, marketed in the UK by Aqua Geocomposites, have been proven as a robust filter/separator/drains between ballast and subgrade.

The purpose of the rig is to carry out simulations in order to gain further data on the performance of geosynthetics so that purpose-made materials can be manufactured that extend track life.

The hydraulic-powered ram actuators can be programmed to load the track dynamically to simulate anything from an empty passenger train to a fully loaded goods train, or an ultra-high-speed train of the future. Trafficking frequency - ten times per day, once per week, can also be modelled.

Results of the work will be published, as they become available.