Dynamic contact between CRTS Ⅱ slab track and bridge due to time-dependent effect of bridge and its influence on train-track-bridge interaction

摘要

Concrete creep and concrete shrinkage are unavoidable in the operation of concrete bridges in high-speed railways, which lead to bridge deformation and then cause gaps between CRTS (China Railway Track System) II slab track and bridge. Aiming at the dynamic contact between CRTS II slab track and bridge due to time-dependent effect of bridge and its influence on train-track-bridge interaction, this work proposes a method for investigating this dynamic contact behavior after exploring its generation mechanism. Adopting the established model, the nonlinear contacts between CRTS II slab track and bridge are deeply analyzed from static and dy-namic perspectives. Finally, the influence of the dynamic contact on the train-track-bridge interaction is also investigated. Results show that the proposed methodology is effective in studying the contact behaviors between CRTS II slab track and bridges subject to time-dependent effect of bridge. Gaps appear at beam-end locations, and sharp contact behaviors are aroused at the locations of gap-edges. The length of gap is greatly decreased by running train. Creep and shrinkage have great influence on the train vibrations, while have almost no effect on track-bridge vibrations. Interlayer forces of track are obviously affect by bridge deformation and running train.