Coupled Train-Bridge Vibration and Dynamic Characteristics of Long-Span T-Shaped Rigid Frame Railway Bridge

To study the characteristics of coupled train-bridge vibration and dynamic performance of a long-span T-shaped rigid frame railway bridge, taking the Mashuihe bridge on the Yichang-Wanzhou railway line as an example, a three-dimensional finite element model for coupled train-bridge vibrations was built, and each carriage of a train was modelled by a 31-degrees-of-freedom dynamic system. Field tests were conducted to determine the free vibration characteristics as well as the strain, displacement, and acceleration of the bridge structure under trains moving at different speeds and braking at a specified position from a set speed. Therefore, the dynamic responses of the Mashuihe bridge was studied comprehensively, both numerically and experimentally. The calculated results were in good agreement with the corresponding experimental results. The dynamic responses of the bridge satisfied the requirements of the code, and the bridge exhibited good lateral and vertical stiffness. The dynamic coefficients of the mid-span and the top of the pier was 1.08, which indicates that the impact of train braking has little effect on the bridge structure. The dynamic responses of the carriages increased with increasing speed, but also satisfied the requirements of the code. The carriages exhibited satisfactory safety and stability.