Loading-history-based track–bridge interaction analysis with experimental fastener resistance

• Conducting experiments to determine nonlinear resistance of selected rail fastener.
• Formulation of track–bridge interaction analysis framework for rail traffic.
• Formulation of double-spring model of selected rail fastener.
• Case study on calculation methods and resistance curves.

Track–bridge interaction (TBI) analysis is usually required to determine the longitudinal stresses and displacements of a coupled system under various temperatures and trainloads and to guarantee the serviceability and safety of track structures. Its results can be used to determine the installation of rail expansion devices and even the structural designs of bridges. To improve calculation accuracy and assist with bridge design and construction investment decisions, this study proposed a nonlinear TBI analysis framework that accounted for the loading-history effects and changes in the longitudinal resistance of rail fasteners in various load cases. Laboratory experiments were conducted to determine the accurate nonlinear features of a kind of rail fastener commonly used in elevated urban rail transit traffic in China. The proposed method was applied in a case study to calculate the longitudinal stresses and displacements of a seven-span track–bridge system in comparison with the conventional linear superposition method. The results obtained using experimental longitudinal resistance displacement curves (RDCs) were also compared with those obtained using curves in the Eurocode. Both the calculation methods and the RDCs of rail fasteners were found to have considerable effects on longitudinal additional rail stresses and the relative longitudinal displacements between beam ends.