Geocomposite technology: reducing railway maintenance

The XiTRACK three-dimensional track reinforcement technique has been very successful in overcoming difficult, long-standing track problems on the railway. This success led to the specification of the technique for use at Deep Wharf level crossing, Purfleet. This was the first time that the technique had been used to reinforce the track structure at a level crossing. The main technical challenge was the application of the technique to stabilise the track over very poor ground, namely the very soft alluvial soils present at the site. A review of other proposed methods, such as concrete foundations and/or piles, illustrated the cost-effectiveness of the reinforcement method: in particular, the rapid installation of the system (the polymer cured within 15 s) minimised track downtime and thus enabled considerable cost savings to be achieved. The design process adopted was used to predict track behaviour before and after treatment, which enabled the design of the most appropriate polymer rheology and polymer distribution and loading levels to achieve optimum performance and ensure that the technique worked. This paper describes the work performed at Purfleet using the technique, including measured acceleration time histories before and after treatment.