千米级跨度桥上无缝线路实际锁定轨温测试方法研究

RESEARCH ON MEASUREMENT METHOD OF ACTUAL STRESS-FREE RAIL TEMPERATURE OF CONTINUOUS WELDED RAIL ON KILOMETER-LEVEL SPAN BRIDGE

  • 摘要: 实际锁定轨温的准确测量对于保障高速铁路运营安全和指导线路养护维修至关重要。以五峰山长江大桥为背景,通过现场实测数据分析了线路运营前后的实际锁定轨温变化规律及原因;基于有限元理论,建立了无缝线路-千米级跨度悬索桥空间耦合模型,分析了温度、车辆荷载下的桥梁纵向、垂向空间变形及桥上无缝线路纵向附加力间的映射关系,在此基础上提出了适用于千米级跨度桥上无缝线路实际锁定轨温的测试方法。结果表明:千米级跨度桥上无缝线路复杂且较大的附加力,致使现有测试手段无法获得线路真实的、准确的实际锁定轨温。主跨各点的伸缩力与桥梁的纵向位移、挠曲力与桥梁垂向变形、温度与温度挠曲力、伸缩附加力均呈显著的线性映射关系;并基于映射关系提出了一种可剔除附加力影响的实际锁定轨温监测方法。研究成果可为千米级跨度桥上无缝线路的监测测点布置及养护维修提供参考。

     

    Abstract: The actual stress-free rail temperature is very important to ensure the safety of high-speed railway operation and guide the line maintenance. With Wufengshan Yangtze River Bridge as the background, the variations of the actual stress-free rail temperature before and after the line operation and its causes were analyzed through the field measurement data. Furthermore, the spatial coupling model of CWR (Continuous Welded Rail)-kilometer-level span bridge was constructed based on the finite element theory. The mapping relationship between the longitudinal and vertical spatial deformation of the bridge and the longitudinal additional force of the CWR under the load of vehicles and temperature was studied numerically. On this basis, a method for measuring the actual stress-free rail temperature of CWR on the kilometer-level span bridges was proposed. The results show that the additional force of the CWR on the kilometer-level span bridge is complex and large. As a result, the existing test methods can not obtain the real and accurate actual stress-free rail temperature of the rail. On the main span, the expansion force and the longitudinal displacement, the deflection force and the vertical deformation all show an obvious linear relationship; the temperature has an obvious linear relationship with the temperature deflection force and the expansion additional force. Based on the linear relationship, an actual stress-free rail temperature monitoring method was proposed which can eliminate the influence of additional forces. The research results can provide a reference for the monitoring point layout and maintenance & repair of CWR on the kilometer-level span bridges.

     

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