公铁两用钢桁梁斜拉桥索梁锚固点位置影响研究

Research on Effect of Cable-girder Anchorage Point of Highway and Railway Bi-purpose Cable-stayed Bridge with Steel Trussed Girder

本文以公安长江公铁两用特大桥为工程背景,针对索梁锚固点位置(即索梁锚固点与主梁截面形心的相对距离)对大跨度钢桁梁斜拉桥受力特性的影响展开研究。利用Midas有限元软件,在成桥工况下和活载工况下,建立一系列不同索梁锚固位置的简化梁模型,通过对比不同情形下各主塔支反力、主梁弯矩、主塔塔底弯矩、斜拉索索力和跨中位移的计算结果,得出索梁锚固点位置与斜拉桥内力变化规律,为今后同类型桥梁的设计提供理论参考。

Taking Gongan Yantze River highway and railway bi-purpose cable-stayed bridge as engineering background, Midas finite element software is applied to research cabie-girder anchorage point （the relative distance between anchorage point and centroid of main girder） which has effects on mechanical performance of large span cable-stayed bridge with steel trussed girder. A series of simplified beam element models are built according to load cases of completed bridge stage and live load stage, and support reacting forces of main towers, bending moment of girder and towers, cable＇ s forces and mid-span deflection are calculated and compared to seek stresses variation patterns of cable-stayed bridge as cable-girder anchorage point changes. The research results are of great theoretical reference for design of the same kind of bridges.