Experimental Analysis of the Vertical Track-Bridge Interaction in Railway Bridges with Ballasted track

Abstract

Realistic vibration predictions of railway bridges during high-speed train crossings require reliable dynamic input parameters for the applied calculation model. In par-ticular, the dynamic stiffness and damping properties of the ballast superstructure for the mathematical consideration of the vertical track-bridge interaction significantly influence the generated calculation results. However, due to a striking scattering of model-related characteristic values available in literature, adequate and realistic con-sideration of the dynamic properties of the vertical track-bridge interaction in vibra-tion predictions is associated with considerable uncertainties. This uncertainness il-lustrates the need to determine experimental-based and reliable characteristic values. For targeted and isolated research of dynamic characteristics of vertical track-bridge interaction, a unique large-scale test facility was developed at the Institute of Struc-tural Engineering at TU Wien, which replicates a section of ballast superstructure on a railway bridge on a scale of 1:1 and excited to vertical movements. This contribution presents substantial results and findings from the experiments, focussing on the deter-mination of the ballast superstructure's dynamic stiffness and damping values, which can further be implemented in practical applications for vibration calculations. In ad-dition, the experiments are used to assess the currently applicable international and national standardised permissible structural accelerations for railway bridges during high-speed train crossings.