焦柳线酉水大桥上货物列车脱轨分析

结合自动控制理论，研究了桥上列车脱轨的力学机理，发现桥上列车脱轨是列车-桥梁时变系统横向振动丧失稳定的结果。根据桥上列车脱轨能量随机分析理论，对焦柳线酉水大桥上货物列车是否脱轨进行了计算和分析，并得到了列车脱轨时此系统振动响应的时程曲线；同时，提出了该桥在不采取加固措施的条件下预防列车脱轨的限速建议值，该值与该桥实车振动试验所确定的限速值一致。最后，指出我国《铁路桥梁钢结构设计规范》中制订连续钢桁梁桥横向刚度限值时存在的问题，论证了按列车脱轨能量随机分析理论重新制订桥梁横向刚度限值的必要性。

Derailment analysis of freight train on Youshui Bridge on Jiaoliu line

Using automatic control theory, mechanical mechanism of derailment of train running on a bridge was discussed. It is found that the derailment results from losing stability of transverse vibration of train-bridge time-variant system. According to the theory of random energy analysis of train derailment on the bridge, a derailment case of freight train running on Youshui Bridge in Jiaoliu line was calculated and analyzed, respectively. The calculated results are corresponded to the real results, and the time history curves of vibration response of the system were obtained when the train derails. Meanwhile, before reinforcing the bridge, the suggested limit value of velocity for preventing train on the bridge from derailment was presented, which is consistent with the limit velocity value obtained by field test. The fundamental problem is also pointed out in stipulating for the limit value of lateral rigidity of continuous steel truss girder bridge in the design criterion for steel structure of railway bridge in China. It is necessary to modify the limit value of lateral rigidity of railway bridge based on the theory of random energy analysis of train derailment on the bridge.