Modelling and Application of Polyurethane Geocomposites for High-Speed Ballasted Railway Tracks including Transition Zone Dynamics

The running of high-speed trains on ballasted railway tracks requires excellent track geometry and reliability. Three-dimensional polyurethane GeoComposites have been used at many sites across the UK to help solve traditional ballast maintenance issues that arise at critical track assets like switch and crossings and transition zones. This paper presents work done on the technique and shows the results of laboratory tests and real site application. In particular the paper concentrates on the application of the technology to transition zones. The issues surrounding transition zone dynamics are discussed and the problem is analysed through the results of advanced 3-dimensional finite element modelling using the DART3D software. The simulations presented in this paper show how the transition fault develops and how the track stiffness is affected by different transition attributes, such as voiding and track stiffness changes. The use of polyurethane GeoComposite technology for high-speed transition zone reinforcement is then presented and the results of simulations shown as to its effectiveness.