Alternatives to sand blanketing
Geotextile Filters

Sand blankets proved an effective solution to treating mud-pumping, however it was a time consuming and expensive option. As the geosynthetic industry developed and heavier weight geotextiles became available it became apparent they may offer an alternatives to sand blanketing.

Following extensive research it was established that the pore size of filter geotextiles were not sufficiently small to prevent migration of fines, meaning the slurry was still able to contaminate the ballast.

However it was established that when used in conjunction with a sufficiently robust non-woven geotextile the sand blanket thickness could potentially be reduced from the standard 300mm thickness and still act as an effective treatment for mud-pumping.

Best practice guidance

Further research into the use of geosynthetics in trackbed resulted in Network Rail including classes of geosynthetic into their best practice guidance for trackbed investigation and design of remedial measures.

These included a geotextile separator such as GEOfabrics RK1 used to separate the sand blanket from the ballast, and a Robust Geotextile such as GEOfabrics RK9 used where separation is required between a coarse granular layer and ballast where a higher level of abrasion is expected.

Research was also conducted into using an impermeable barrier to prevent mud-pumping. An impermeable membrane does prevent migration of fines into the ballast, but it also prevents the water from escaping. This means the slurry cannot desiccate and there is a consequential reduction in trackbed quality, and for this reason the use of impermeable membrane below ballast is not permitted in UK rail.

The use of a geotextile separator with a 100mm sand blanket became common practice, but the long term aim was still to develop a geosynthetic that could completely replace all the functions of a sand blanket. This research culminated in the development of TrackTex.

Preventing Mud Pumping, Ensuring Track Stability

Comprehensive Support Delivers Trackbed Performance

At GEOfabrics, we provide technical support to help you get the most out of TrackTex and address the cause of mud pumping. This ensures the stability and performance of your tracks. Our team of experts utilizes advanced techniques and technologies to deliver effective solutions tailored to your specific needs

Professional Development Hours

GEOfabrics continuing education sessions provide technical training on specifying and using TrackTex. These sessions contribute to PDH hours.

Trackbed Stabilization

Geosynthetics are widely used as a way to improve ballast performance under railways. GEOFabrics RK4 is a geocomposite comprising a stabilizing geogrid bonded to our RK1 needlepunched non-woven sep...

Symptoms of Mud Pumping

The symptoms of Mud Pumping are similar to those of life expired ballast, i.e. wet spots appearing at the surface of the ballast accompanied by rapid deteriorating of track geometry. However, from ...
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Explore our latest case studies showcasing our expertise.

Diamond Crossing Replacement with TrackTex

In Detroit Lakes, MN, a frequently trafficked diamond crossing operated by Canadian Pacific and BNSF had experienced frequent fouling because of mud-pumping. Mud pumping results in ballast failure,...

Coos Bay Line Tunnel 21 Rehabilitation

The Coos Bay Rail Line is owned and operated by the Port of Coos Bay. It spans 134 miles from Coquille Oregon to Eugene Oregon, providing connections to the North American rail network for manufact...

Crossing Repair and Replacement using TrackTex

This road crossing had been replaced and repaired multiple times due to issues with track geometry movement and differential settlement of the highway and railroad. Union Pacific Engineers assessed...