Long-term monitoring of steel railway bridge interaction with continuous welded rail

The continuous welded rail (CWR) is nowadays standardly used on almost all modern railway bridges. However, its placement results in an interaction between CWR and the structure, which brings not only longitudinal forces on the substructure, but also significant additional stresses in the rail. These stresses can result either in the rail break, or in a track buckling. Unfortunately, input parameters for performing a numerical analysis are hardly accessible and they vary significantly in different sources. Because of that, an extensive long-time monitoring of the rail-bridge interaction was performed on a bridge with an unusual combination of ballasted track, direct fastening and a barrier in the ballast. The paper presents the results of the monitoring and shows the analysis and evaluation of formulas, defining the fastening nonlinear stiffness of track to the bridge connection. The influence of the temperature on the ballast stiffness is also analysed.