Geotextiles are a type of material used in railway construction to improve the stability and performance of track beds and embankment structures. They are made of synthetic fibers that are woven or needle-punched together to form a permeable fabric.
Geotextiles for railway construction
When used in railway construction, geotextiles are typically placed between the different layers of the construction, such as the subgrade, which is the layer of soil or rock beneath the track bed, and the soil. They act as a separation layer, preventing the mixing of different soil types and helping to maintain the stability of the track bed. Geotextiles also help to improve drainage and reduce the risk of erosion by allowing water to pass through the fabric while keeping soil in place.
For use between the ballast and the subgrade, a special, abrasion resistant, nonwoven geotextile is recommended to withstand the constant abrasive forces of the granular material in the ballast.
The use of a geotextile will also help prevent the typical pumping effect (caused by compression of a track bed that is not properly drained as the train passes over the track), as it lets water evacuate the track while keeping the soil fines in place. In combination with additional drainage systems such as french drains, the structural stability will increase significantly.
In addition to these functions, geosynthetics can also be used to reinforce embankments and slopes in railway construction. This is done by placing the geosynthetic behind the embankment and filling it with soil. The geosynthetic helps to keep the soil in place, reducing the risk of landslides and erosion.
Overall, geotextiles are a valuable tool in railway construction as they can help to improve the stability and performance of track beds and embankment structures and reduce the risk of erosion and landslides.