Laying ballastless tracks on a long-span railway bridge with a main span greater than 300 m is a challenge in engineering practice and has aroused significant concerns. Influenced by complicated environmental factors, long-span railway bridges in service deform with large amplitudes and complex shapes, which may result in damage to the track structure and threaten the running safety and ride comfort of trains. In this study, we investigate some typical statics and dynamics problems under the actual conditions of a long-span cable-stayed high-speed railway bridge with a main span of 400 m and laying ballastless track. The track-bridge finite element model and dynamic interaction model of the train-track-bridge system are first established. Furthermore, the influences of the complicated environment-induced bridge deformations are comprehensively investigated using the curvature method that reveals the deformation compatibility of the bridge-track system and indicates the dynamic interaction behavior of the train-track-bridge system subject to train running speeds and bridge deformations. Results indicate that excellent dynamic performance of the train-track-bridge system can be achieved by setting an elastic cushion of 0.1 N/mm³ under the track bed. Interface damage between track layers will not occur directly because of the complex deformations of the bridge decks. The bridge deformations induced by the environmental temperature and the concrete creep are qualified. The dynamic responses of the train-track-bridge system are also excellent under the excitations of bridge deformations. Dynamic simulations of the train-track-bridge system are proposed to evaluate long-span bridge deformations subject to complicated service situations in comparison with an oversimplified statics evaluation.

在主跨大于 300 m 的大跨度铁路桥梁上铺设无砟轨道是工程实践中的一项挑战，引起了人们的极大关注。受复杂环境因素影响，在役大跨度铁路桥梁变形幅度大、形状复杂，可能对轨道结构造成破坏，威胁列车运行安全和乘坐舒适性。在本研究中，我们研究了主跨为400 m、铺设无砟轨道的大跨度斜拉高速铁路桥在实际条件下的一些典型的静力学问题。首次建立了列车-轨道-桥梁系统的轨道-桥梁有限元模型和动力相互作用模型。此外，采用曲率法综合研究了复杂环境引起的桥梁变形的影响，揭示了桥梁-轨道系统的变形相容性，并指示了列车-轨道-桥梁系统在列车运行速度和桥梁变形下的动力相互作用行为. 结果表明，通过设置 0.1 N/mm 的弹性缓冲垫可以实现列车-轨道-桥梁系统的优异动态性能。³在轨道床下。由于桥面的复杂变形，轨道层之间的界面损坏不会直接发生。环境温度和混凝土徐变引起的桥梁变形合格。在桥梁变形的激励下，列车-轨道-桥梁系统的动力响应也很好。与过于简化的静力学评估相比，提出了列车-轨道-桥梁系统的动态模拟来评估大跨度桥梁在复杂服务情况下的变形。