Dynamic performance of continuous railway bridges: Numerical analyses and field tests

In this study, a refined finite element model was built that represented the structural and mechanical properties of railway bridges. A coupled vehicle–bridge vibration model was established to simulate the dynamic behavior of the bridge under moving trains. Field tests were then 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. The dynamic response of the bridge was found to increase with the train speed, but the main beam of the bridge was more affected by a train braking than the one passing over it. Both the bridge and vehicle were found to meet the relevant requirements for safe design and operation, with the train exhibiting good running safety and smoothness, and the bridge structure showing sufficient stiffness and dynamic performance. Based on the field measurements and analytical modeling, it can be concluded that the use of appropriate equipment and the selection of a suitable layout for the sensors permit the assessment of the dynamic behavior of the bridges from vibration measurements. This indicates the potential for the continuous health monitoring of the railway bridges that may be sensitive to the vehicle–bridge interaction.