The Influence of Temperature-Induced Deformation on Dynamic Characteristics of Novel Fabricated Track Beam-End Expansion Area at Long-Span Bridge: A Case Study in China

Prefabricated ballastless tracks are increasingly applied on long-span bridges, necessitating special attention to driving safety and comfort at weak connection areas like beam-end expansion joints. This study, based on the Ningbo-Xiangshan urban railway’s Xiangshangang sea-crossing bridge, establishes a refined train–track–bridge dynamic interaction model incorporating the beam-end expansion joint zone. The dynamic response characteristics of the train under temperature-induced deformation in beam-end expansion area conditions were explored. The research results show that the temperature-induced deformation of the end area of the long-span cable-stayed bridge has a greater impact on the vertical dynamic response of the train, but has a small impact on the lateral dynamic response of the train. Among them, the overall temperature rise and fall state of the long-span cable-stayed bridge has a significant impact on the dynamic response of the train. When a train passes through the beam-end expansion area, compared with the prefabricated track, the beam end area has a more obvious impact on the dynamic response of the train, but its scope of influence is only limited to the telescopic transition within the segment range. The temperature-induced deformation in the beam end area will have a greater impact on the dynamic response of the train, but the dynamic response of the train can still be controlled according to the relevant limits in the current standard. The results of this research can provide technical support for laying prefabricated tracks on large-span urban railway bridges, and provide technical reference for the optimization of expansion joints in the beam end area.