Behavior Characteristics of a Booted Sleeper Track System According to Substructure Deformation

Abstract

In booted sleeper floating track systems wherein the concrete bed, rail, and sleeper are structurally separated, mismatches can occur between the substructure and track owing to deformations. Nevertheless, the mutual behavior between substructures and track systems has not been studied extensively. To address this limitation, the effect of substructure uplift and subsidence on the deformation of a boosted sleeper floating track system installed in a subway box tunnel was analyzed using finite element analysis. A detailed three-dimensional model consisting of all track system components was constructed to determine the interaction between the rail and concrete bed. The sleepers were observed to rotate in response to substructure deformation, and their resulting contact conditions on the concrete bed were analyzed to determine the track status accordingly. The zones of likely tension and shear cracking in the concrete bed were then determined to provide focus areas for track design and maintenance efforts. The results of this study can be used to improve the design and inspection of floating track systems to ensure the safety and functionality of railway tunnels in areas likely to experience uplift or subsidence.