大跨度悬索桥上无缝线路伸缩力影响因素分析

以五峰山长江大桥上无缝线路为研究对象,建立悬索桥上无缝线路一体化空间耦合模型,研究钢轨伸缩调节器铺设位置,悬索桥主塔、主缆、吊索等结构的温度变化,主缆与吊索初始轴力等因素对钢轨纵向力的影响。研究结果表明:跨中铺设钢轨伸缩调节器不能显著改善悬索桥上钢轨纵向受力,主梁两端需要各铺设1组单向伸缩调节器。随着主塔温度升高,钢轨纵向力、吊索及主缆整体受力增加;随着主缆温度升高,钢轨纵向力增加,但会造成吊索及主缆整体受力降低;随着吊索温度升高,钢轨纵向力有微小的增幅;随着主缆与吊索初始轴力降低,钢轨纵向力稍有减小。悬索桥主塔、主缆、吊索温差及主缆与吊索初始轴力对钢轨纵向力影响较小,当不考虑梁轨相互作用对吊索、主缆等结构或构件受力变形的影响时,可以将悬索桥简化为连续梁桥进行计算分析。

Analysis on Influencing Factors of Rail Expansion Force of CWR on Long Span Suspension Bridge

Taking the Wufengshan Yangtze River Bridge as the research object,the spatial coupling model of continuous welded rail(CWR)on suspension bridge was established to analyze the influence of the laying position of rail expansion joint,the temperature change of main tower,main cable,suspender and other structures of suspension bridge,the initial axial forces of main cable and suspender and other factors on the rail longitudinal force.The results show that the rail expansion joint set at mid-span of suspension bridge cannot reduce the rail longitudinal force,one set of the rail expansion joint should be laid at both ends of the main girder.As the temperature of main tower increases,the rail longitudinal force and the overall stress of suspender and main cable all increase.As the temperature of main cable increases,the rail longitudinal force increases,but the overall stress of suspender and main cable will decrease.As the suspender temperature increases,the longitudinal force of rail increases slightly.As the initial axial forces of main cable and suspender decrease,the rail longitudinal force slightly decreases.The temperature difference of main tower,main cable,suspender and initial axial forces of main cable and suspender have little influence on the rail longitudinal force.When the influences of girder rail interaction on the stress and deformation of suspender,main cable and other structures or components are not considered,the suspension bridge can be simplified as a continuous girder bridge for calculation and analysis.