菱湖大桥主跨钢拱肋快速安装施工方案设计

Design of Rapid Installation Construction Scheme for Steel Arch Ribs of Main Span of Linghu Bridge

无锡菱湖大桥主桥为中承式三跨钢桁架系杆拱桥,跨越三级航道。为解决跨内河航道安装钢拱肋施工难度大、安全风险高、封航压力大等难题,采用支架、浮吊联合施工技术吊装大节段钢拱肋,并通过有限元仿真、现场监测进行验证。结果表明,支架、浮吊联合施工技术方案安全合理。吊装过程中,钢拱肋最小应力为-48MPa,第一阶稳定性系数最小为34.8,最大整体稳定应力比为0.3,支架立柱最小组合应力为-46.4MPa,最大偏位为7.92mm,结构受力和稳定性满足要求。

The main bridge of Wuxi Linghu bridge is a half-through three-span steel truss tied arch bridge,crossing the three-level navigation channel.In order to solve the construction difficulty of installing steel arch ribs in the inland river channel,high safety risks,and high pressure of navigation channel closing and so on,the verification is made by using the construction technology with support and floating crane to lift large sections of steel arch ribs,and the finite element simulation and on-site monitoring.The results show that,the scheme for the construction technology with support and floating crane is safe and reasonable.During the lifting process,the minimum stress of the steel arch rib is-48MPa,the minimum first-stage stability coefficient is 34.8,the maximum overall stability stress ratio is 0.3,the minimum combined stress of the support column is-46.4MPa,and the maximum deviation is 7.92mm.The structural stress and stability meet the requirements.