超大跨CFST拱桥管内混凝土灌注方案比选研究

Comparison and selection of concrete filling programs in tubes for super-large span CFST arch bridges

为探讨扣索调载对拱肋混凝土灌注过程的影响,以某跨径575 m的中承式钢管混凝土拱桥为工程背景,采用MIDAS/Civil建立空间有限元模型对比分析大桥管内混凝土考虑过程调载和不调载两种灌注方案。结果表明:过程考虑调整,能有效抑制拱肋1号—8号节段下挠,9号—11号节段上挠,以及控制拱肋横向偏位的发展;两种方案下,管内混凝土最大拉应力都能满足抗拉强度设计要求,但过程调整管内混凝土最大拉应力能有效降低76%。

To explore the impact of cable tension adjustment on the pouring process of arch rib concrete,a mid through steel tube concrete arch bridge with a span of 575 m was used as the engineering background.A spatial finite element model was established using MIDAS/Civil to compare and analyze two pouring schemes for the concrete in the bridge pipe,including process adjustment and non-adjustment.The results show that considering adjustments during the process can effectively suppress the downward deflection of the arch rib segments 1#—8#,and the upward deflection of segments 9#—11#,as well as control the development of lateral deviation of the arch rib;Under both schemes,the maximum tensile stress of the concrete inside the pipe can meet the design requirements for tensile strength,but adjusting the process can effectively reduce the maximum tensile stress of the concrete inside the pipe by 76%.