Research on the Longitudinal Stiffness of Pier and Temperature Span of High-speed Railway Integral Bridge

Research purposes: The beam-rail interaction is closely related to the value of the design parameters of the high-speed railway internal bridge such as span layout and pier stiffness. When the values are not reasonable, the problems such as excessive deformation, instability and fracture of the rail on the bridge will occur. To ensure the safety of the lines on the bridge and obtain the value range and related relationship of the design parameters, this paper simulates the resistance of beam and rail based on the double-line and multi-segment broken lines, and establishes an equilibrium equation of the CWR to obtain the parameters like the additional stress and displacement of the rail. Combining rail strength, the relative displacement of beam and rail, displacement of pier top, rail gap width and rail stability, respectively, the relationship between the bridge temperature span and the piers' longitudinal stiffness and the value range are determined. Research conclusions:(1) The temperature span and the piers' longitudinal stiffness are mainly affected by the rail strength constraint. The relative displacement of beam and rail, the displacement of the pier top, the rail gap width constraint and the stability of the rail have little influence. (2) The relevant calculation formulas for the two parameters of temperature span and piers' longitudinal stiffness under the limit of the code are put forward. (3) The algorithms and calculation formulas can provide a certain reference for the design of integral bridges. © 2022, Editorial Department of Journal of Railway Engineering Society. All right reserved.