Impact responses of railway concrete sleepers with surface abrasions

In reality, railway infrastructure experiences aggressive wheel-rail contacts and changing operational actions. Especially in sharp curve and high gradient, trains induce even much-more aggressive actions on the infrastructure. Our critical review reveals that railway concrete sleepers degrade over time. The ballast angularity causes differential abrasions on the soffit or bottom surface of sleepers (especially at railseat zone). In addition, in sharp curves and rapid gradient change, longitudinal and lateral dynamics of rails increase the likelihood of railseat abrasions in concrete sleepers due to the unbalanced loading conditions. Such the abrasions affect not only the wheel/rail interaction and track geometry, but they also undermine structural integrity of the track structures. The latter is by far more crucial as it underpins the public safety of railway networks. This paper presents a nonlinear finite element model of a standard-gauge concrete sleeper in a track system, taking into account the nonlinear tensionless nature of ballast support. The finite element model was validated using static and dynamic responses in the past. In this paper, the dynamic effects of surface abrasions, including surface abrasion and soffit abrasion, on the impact responses of sleepers are firstly highlighted. The outcome of this study will improve the rail maintenance and inspection criteria in order to establish appropriate and sensible remote track condition monitoring network in practice. The insight into the impact behaviour will improve predictive track maintenance scheme by properly informing track engineers to avoid costly unplanned corrective track maintenance.