大跨度铁路斜拉桥极限承载力研究

Study on the ultimate load-carrying capacity of large-span railway cable-stayed bridge

为了对韩家沱长江铁路大桥的稳定性能进行科学评价,采用同时考虑几何非线性、材料非线性和个别构件极限承载力的全过程分析方法,对韩家沱长江铁路大桥施工及运营阶段进行了极限承载力分析,在采用结构上所有荷载等比例增加的加载方式下,计算结果表明,大桥施工及运营阶段的稳定安全系数均大于2.0,大桥达到极限承载力状态是由处于最不利受力状态的构件进入塑性或发生局部失稳造成的,大桥的稳定安全系数在施工过程中呈现出整体微小下降趋势,每个梁段悬臂施工不同工况下结构的稳定安全系数具有明显波动。

In order to assess the stability of Hanjiatuo Yangtze River Railway Bridge scientifically, the whole process analysis method, which takes into account the geometric nonlinearity, material nonlinearity and the ultimate load-carrying capacity of individual members has been adopted, and the ultimate bearing capacity of the Hanjiatuo Yangtze River Railway Bridge during the erection and service stages has been analyzed. All loads on the structure are increased with equal ratio. The result shows that the safety coefficients of the bridge during erection and service stages are all greater than 2.0, and entering plastic stage or local instability of the individual members is the reason that caused the whole bridge reaching its ultimate load-carrying capacity state. The stability safety coefficients decrease slowly during the erection stages, and vary obviously during the cantilever construction stages of each segment.