刚性悬索加劲弦连续钢桁梁顶推技术研究

Research on Pushing Technology of Continuous Steel Truss Beams with Rigid Suspension Cable Stiffening Chords

济南黄河公铁两用桥全长128m+3×180m+128m,是石济铁路客运专线工程横跨黄河的重点项目,为我国公铁两用桥上首次采用刚性悬索加劲弦连续钢桁梁结构。提出了3桁5跨的"钢桁梁带加劲弦顶推"刚性悬索加劲弦钢桁架梁桥施工新技术,给出了顶推的关键步骤,采用MIDAS-Civil软件对钢桁梁带加劲弦顶推施工全过程进行了仿真数值分析,解决了带弦顶推最大悬臂工况、加劲弦合龙等系列技术难题,验证了钢桁梁带加劲弦顶推施工新技术的安全性和可靠性。同时提出了落梁后吊杆安装的两个技术方案,通过数值模拟和综合考量,明确最优的技术方案。所提出的钢桁梁带加劲弦顶推施工新技术为我国类似的跨江、跨河、跨高速大跨度桥梁工程施工提供了参考依据。

The entire length of Jinan Yellow River combined highway and railway bridge is 128 m＋3 × 180 m＋128 m. This bridge is a key project of Shiji railway passenger special line across the Yellow River, and it is the first continuous steel truss beam structure with rigid suspension cable stiffening chords applied in combined highway and railway bridges in China. A new construction technology of three-truss and five-span rigid continuous steel truss beam with suspension cable stiffening chords is proposed in this paper, namely, pushing technology of steel truss with stiffening chords. The key steps of pushing technology are detailedly described. Numerical analysis on the full process of construction is simulated using MIDAS-Civil software. The technical problems are resolved including the maximum cantilever of chord pushing and closure of stiffening chords. The safety and reliability of pushing technology for steel truss with stiffening chords are validated. Two technical schemes of hanger installation are proposed. An optimal technical solution is proposed through numerical simulation and comprehensive considerations. This new construction technology can provide a good reference for similar large-span bridge constructions across rivers or highways in China.