Geofabrics
Solving Trackbed Maintenance Problems with Geocomposites
This article first appeared in the Railway-News magazine, Issue 2 2024.
There are many problematic ground conditions that exist beneath railway tracks. As a result, track stabilisation, track geometry and trackbed maintenance are major headaches for the rail industry, worldwide.
It’s true that a range of solutions have evolved over the years – but many come with cost, time and environmental implications, which are far from ideal.
The Issue
The passage of trains applies dynamic loads to soil beneath the tracks. This results in intense compression and decompression cycles, which can lead to fracturing of the foundations – to the point of collapse. Some of the most widely used methods for solving track stabilisation on railroads involve geocomposites. TrackTex, for example, is used in place of sand blankets to prevent mud pumping.
While sand blankets are successful in curing subgrade erosion, achieving the optimum 300mm layer requires a large volume of excavation. This in itself is expensive and incurs further costs for soil disposal. There’s a requirement for extensive materials to complete the work and the disruption to services causes loss of revenue, too. So, while sand blanketing is still used today, it’s an expensive, slow and unsustainable process.
Geosynthetics: A Solution with a Proven Track Record
Geosynthetics have been used for a number of functions in track construction and rehabilitation for almost half a century. When properly specified and installed, they have been proven to significantly enhance the performance of the trackbed, reducing maintenance costs and increasing design lifetime.
