高速铁路无砟轨道大跨斜拉桥成桥预拱度设置方法

Pre-camber Setting Method for Long Span Ballastless Track Bridge of High-speed Railway

成桥预拱度的设置关系到高速列车运行的舒适性和安全性。提出合理成桥预拱度的计算方法和应满足的基本指标,以昌赣铁路赣江特大桥为例,基于车-线-桥耦合振动分析模型,分析设置预拱度与否对桥梁结构长期使用性能演变的影响,以验证所提方法的可靠性。计算结果表明:预拱度的设置降低了车体垂向加速度、轮重减载率,且服役时间越长,效果越显著,在成桥10 a后,车体垂向加速度较不设预拱度降低约67%,轮重减载率降低约18%,改善了车-线-桥系统动力学性能。所提方法理论清晰、简便可行,对于同类型桥梁的预拱度设置具有指导意义。

The setting of bridge pre-camber is related to the comfort and safety of the long-term high-speed train operation.A reasonable pre-camber setting method for a long-span cable-stayed bridge and the basic in dicators that a reasonable pre-camber should meet were put forward.In the case of Ganzhou Ganjiang bridge of Chang-Gan railway,based on train-track-bridge coupling vibration dynamic simulation model,the influence of pre-camber on the long-term service performance of the bridge was analyzed to verify the reliability of the proposed method.The calculation results show that the setting of pre-camber reduces the vehicle body vertical acceleration and the rate of load wheel load reduction.The longer the service time,the more significant the effect.After ten years of completion of the bridge,the vehicle body vertical acceleration is reduced by about 67%and load wheel load reduction rate is reduced by about 18%compared to the method without pre camber.The proposed method can improve the dynamic performance of train-track-bridge system.The method is clear in theory,simple and feasible,with guiding significance for the setting of pre-camber of similar bridges.