郑万高铁梅溪河大桥拱圈外包混凝土浇筑方法探讨

为了探讨大跨度劲性骨架混凝土拱桥拱圈外包混凝土的合理浇筑方法,针对目前常采用的平衡浇筑与连续浇筑两类方法,以主跨为340 m的郑万高铁梅溪河大桥为研究背景,首先,依托劲性钢骨架的扣索系统,提出采用敏感性分析确定拉索合理位置及索力张拉大小的新方法;其次,采用Midas Civil软件建立主拱圈梁-板组合分析模型,并对分段平衡浇筑和连续浇筑法的结果进行探讨;最后,进一步分析不同工作面数量对于拱桥结构应力、挠度和稳定性的影响。研究结果表明:利用敏感性分析结果,平衡加载法和连续浇筑法均能够有效控制主拱圈截面应力和变形大小;当纵向工作面数量相同时,平衡浇筑法更有利于拱桥施工阶段的稳定性。研究成果可为大跨度混凝土拱桥的修建提供技术支撑。

Discussion on Construction Method of Arch Ring Concrete of Meixi River Bridge on Zhengzhou-Wanzhou High-speed Railway

To investigate reasonable pouring method of outsourced concrete for long-span arch bridges with stiff skeleton,two kinds of different pouring methods of balanced pouring and continuous pouring are considered in this paper with reference to the railway rigid skeleton concrete arch bridge of 340 m main-span on Zhengzhou-Wanzhou high-speed railway.First,reasonable position and cable force values are determined by sensitivity analysis according to the stayed cable system of stiff skeleton.Second,the plate-beam finite element model of arch ring is established by Midas Civil software,and the results of subsection balance pouring and continuous pouring are discussed.Finally,the influences of work face on stress,deflection and stability of the arch bridge are further analyzed.The results show that both methods can effectively control stress and displacement of the arch ring using sensitivity analysis,and balance pouring method is more conducive to the stability of the arch bridge when the number of longitudinal working faces is identical.The research results can provide technical support for the construction of long-span concrete arch bridges.