A holistic design approach using advanced computing tools for railway track modelling

This paper presents a holistic approach to the design of novel track solutions, especially from a geotechnical perspective, by employing advanced computing techniques capable of establishing design specifications and optimising the railway track structure design for light, conventional and heavy freight tracks. The proposed approach uses numerical modelling techniques of the track substructure, and subsequent suitable computing tools for defining and analysing the substructure models and their interfaces, which can then be coupled with the railway superstructure model to analyse the whole vehicle-track interaction and dynamic response. Numerical modelling of the different track design models has been conducted, with comprehensive design considerations and novel reinforcement approaches. The geotechnical material nonlinearity was applied by using the Mohr- Coulomb criteria implemented in a finite element analysis. The numerical results show considerable variation of key parameters such as the axle load, and the ballast and sub-ballast layer thicknesses largely affecting the track behaviour. A comparison has been made between different design solutions for the track substructure. Reasons for the variations in the pressure and displacement distribution patterns have been analysed and discussed, and the selection of the final suitable design for specific subgrade conditions is presented together with appropriate justification.