悬索-斜拉协作体系桥梁总体设计

Research on the Key Technology of Integral Lifting for Long-span Steel Box Arch Rib

韶关某跨江桥受航道和用地条件边界约束,桥梁跨径组合采用(23+340+23)m,全宽8.2 m,主跨恒载总重量达1500t;本桥边中跨比例远超出常规大跨桥型跨径比例范围,如何选择合理的桥型方案直接影响桥梁的安全性和经济性。为探索特殊条件下的桥梁设计方案,构造出一种新型地锚式悬索-斜拉协作体系结构;340m中跨采用单主缆悬索体系,23m边跨采用斜拉背索体系,主缆和背索通过塔顶钢锚箱平衡边中跨拉力;通过设置小角度微型抗风缆,有效解决了通航净空受限条件下抗风缆布置难题。通过方案比较和结构分析表明,在特定的条件下,采用背索斜拉-主跨悬索协作体系合理可行,为今后大跨桥梁建设,提供了可靠的参考和借鉴。

A pipeline bridge in Shaoguan is constrained by the boundary conditions of the waterway and land use.The bridge span combination adopts(23+340+23)meters,with a total width of 8.2 m and a total weight of 1500 t for the main span under constant load;The proportion of mid span on the side of this bridge far exceeds the range of conventional large-span bridge types.How to choose a reasonable bridge type scheme directly affects the safety and economy of the bridge.To explore bridge design schemes under special conditions,a new type of ground anchor suspension cable-stayed cooperative system structure is constructed;The 340 m mid span adopts a single main cable suspension system,and the 23 m side span adopts a cable-stayed back cable system.The main cable and back cable balance the tension of the side mid span through the tower top steel anchor box;By setting small angle micro wind resistant cables,the problem of arranging wind resistant cables under restricted navigation clearance conditions has been effectively solved.Through scheme comparison and structural analysis,it is shown that under specific conditions,the use of a back cable cable-stayed main span suspension cooperation system is reasonable and feasible,providing reliable reference and inspiration for the construction of large-span bridges in the future.