800 m级变截面钢管混凝土飞燕拱与自锚悬索组合桥研讨

摘要：针对800米级超大跨径钢管混凝土拱桥的需求，提出单叶双曲面状变截面钢管混凝土飞燕拱与自锚悬索的组合桥，飞燕式钢管混凝土拱桥的推力与自锚悬索桥的拉力两者平衡，形成自平衡结构体系，拱肋结构受力为主，辅以自锚悬索体系受力，协同工作，优势互补。采用单叶双曲面状变截面钢管的四肢空间桁架拱肋结构形式，减轻了跨中拱肋节段结构自重，降低了跨中节段施工吊装风险难度，增加了拱脚处截面尺寸，拱桥结构的质量中心和刚度中心有效降低，增加了超大跨径钢管混凝土拱桥的稳定性。结合实际工程，进行参数设计，建立Midas有限元模型，进行内力分析计算、模态分析和屈曲分析研究，验证了其结构技术措施的优越性。

Study and Discussion on 800-m Variable Cross-section Concrete Filled Steel Tube Swallow-type Arch and Self-anchored Suspension Cable Composite Bridge

In view of the demand of 800 meter Super Long Span CFST arch bridge, the composite bridge of CFST flying-bird arch and self anchored suspension cable is proposed. The thrust of flying-bird CFST arch bridge and the tension of self anchored suspension bridge are balanced, forming a self balanced structure system. The arch rib structure is mainly stressed, supplemented by the self anchored suspension system, which works together and has complementary advantages. Using the four limb space truss arch rib structure with the univalent hyperboloid variable section CFST, the self weight of arch rib segment in mid span is reduced , the risk and difficulty of mid span segment construction is reduced, the section size at the arch foot is increased, the mass center and stiffness center of the arch bridge structure are effectively reduced, and the stability of the super long span CFST arch bridge is increased. Combined with the actual project, the parameters are designed, the Midas finite element model is established, the internal force analysis and calculation, modal analysis and buckling analysis are carried out, and the superiority of the new structural technical measures is verified.