Influence of Sleeper Base Area and Spacing on Long-Term Differential Settlement in a Railway Track Transition Zone

Paper in proceeding, 2024

A model for simulation of track geometry degradation is demonstrated by predicting and comparing the long-term performance of three transition zone designs in terms of differential settlement and voided sleepers. It includes a calibrated two-dimensional (2D) finite element model of a transition zone between a ballasted track on an embankment and a slab track on a rigid foundation. The influence of using shorter sleeper spacing or a broader sleeper base design to reduce the track stiffness gradient between the two track forms and improve the dynamic vehicle–track interaction is evaluated. The 2D track model includes a state-dependent seven-parameter model of the ballast and subgrade, accounting for potential loss of contact between sleepers and ballast and the interaction between sleepers via the ground, while the vehicle model represents a heavy haul wagon with axle loads 30 tonnes and speed 60 km/h.