斜拉桥上无缝线路纵向相互作用理论及试验研究

Theoretical and Experimental Study on Longitudinal Interaction of CWR on Railway Cable-stayed Bridge

运用梁轨纵向相互作用机理,建立斜拉桥上无缝线路纵向力计算模型,以一座铁路常用双塔钢桁斜拉桥为例,对斜拉桥上无缝线路纵向相互作用规律进行理论和试验研究。分析结果表明:在主桥左右两端各铺设一组单向伸缩调节器,主桥上钢轨纵向力可得到有效的控制,现场试验测试的桥面纵向位移及钢轨伸缩力分布规律与理论计算基本相同,所建立模型可用于斜拉桥上无缝线路纵向相互作用分析;钢轨挠曲力计算时,可在斜拉桥主跨及其邻跨上布置荷载,且不必考虑列车入桥方向的变化;钢轨伸缩调节器可有效减弱列车制动荷载下的梁轨相互约束作用,减小线路受力变形。

The calculation model of longitudinal force of CWR （continuous welded rail） on cable-stayed bridge is established on the basis of the mechanism of longitudinal interaction. With reference to a double-towers steel truss cable-stayed bridge commonly used in the railway, the longitudinal interaction of CWR and the related experiments are studied. Analysis results show that when the rail expansion device is placed on each side of the main bridge, rail longitudinal force can be effectively controlled, and the distribution of the line longitudinal displacement and the rail expansion are basically the same after theoretical calculation, and the calculation model can be used to analyze longitudinal restraint interaction of CWR on cable-stayed bridge. Rail bending forces are calculated with load on the main span and its adjacent spans in independence of the direction of the train. The rail expansion device effectively weakens the longitudinal restraint interaction between the beam and the rail under the load of train braking, and minimizes track deformation.