The Importance of Geosynthetics in Railways

Comprehensive research has been undertaken recently to investigate the characteristics of railway substructure with the aim of providing better guidelines to construct stronger, safer and more economical tracks. The studies continue to show that the use of geosynthetics prove to have some major benefits in rail construction.

Over the years geosynthetics have been utilised in rail structures for:

Soft subgrade stabilisation as a sustainable alternative to traditional techniques Ballast reinforcement Separation / filtration to improve the stability of the subballast and capping Basal reinforcement of rail embankments Reinforced steep slopes Waterproofing and drainage

In these applications geosynthetics (geogrid and/or geotextile composites) are exposed to very severe conditions, both from the mechanically aggressive characteristics of the ballast and to the high dynamic load levels transmitted by trains.

The use of geosynthetics in railways has a number of key benefits.

These proven benefits include:

1. Ballast Breakage Control – inclusion of robust geogrids and geocomposites such as the German made, Secugrid® geogrid and Combigrid® geogrid/geotextile geocomposite under the ballast reduces the ballast breakage and increases the life of ballast. This significantly reduces the maintenance costs and increases the overall track lifetime.

2. Rail Track Settlement Reduction – inclusion of robust Secugrid® geogrid and Combigrid® geocomposite under the ballast layer and/or on between the subgrade and rail structure can reduce the settlement and deformation of the rail track. On the other hand, inclusion of Secugrid and Combigrid® on top of the soft subgrade improves the bearing capacity of the subgrade, reduces the normal stress on the subgrade, and controls differential settlements.

3. Subballast Thickness Reduction – the use of Secugrid® and Combigrid® under the subballast can reduce the thickness of this layer and improve the performance of the rail track.

Want to know more about how our range of geogrids and design tools could assist your next railway project? Please call us now or contact the Tech Team at: gbs@globalsynthetics.com.au.