Assessment of high-speed slab track design

This article describes design principles for non-ballasted railway slab track for use by high-speed trains. The main advantages of non-ballasted track are low maintenance, increased life and the ability to run high-speed and tilting trains. Where track is built on soil likely to settle, reinforcement is needed to the slab, at the neutral line or at the top and bottom, or in the use of bridge-like substructures supported by piles. Three existing track systems are briefly described. Part of the design process involves analysis of the static and dynamic behavior of the slab track under various loadings. Dynamic analysis is performed in the program DARTS_NL by two-dimensional modelling, with track structure represented by a series of hard and soft layers, and a vehicle as a mass-spring system. Dynamic simulations collect data on car body acceleration, wheel-rail contact forces and displacements of the concrete slabs. Results are shown for application of dynamic analysis to the three track forms. It is pointed out that new structures should be fully analysed at the design stage.