单索面钢箱叠合梁斜拉桥锚固区力学性能分析

Mechanical Properties Analysis on the Anchorage Zone of Cable-stayed Bridge with Single Cable Plane and Steel Cantilever Beam

以黑瞎子岛乌苏斜拉桥为工程背景,基于非线性理论和稳定分析理论,通过对关键部位构件的细化分析模型,研究了索梁锚固区、索塔锚固区及箱梁长挑臂的局部力学性能和稳定性。结果表明:索塔锚固区横桥向塔壁混凝土沿横桥向正应力值在拉索导管内壁出现应力集中现象,附近混凝土出现拉应力,拉应力值为0.638MPa,小于桥塔混凝土抗拉强度设计值;索梁锚固区顶底板应力均较小,钢锚箱局部应力集中现象较明显,在设计中应充分考虑索力锚固区锚箱的应力集中现象,建议采取锚箱局部加劲的方式防止钢锚箱的最先失稳破坏;钢挑臂结构的最低稳定系数为7.85,结构的稳定安全性满足要求。

The paper is based on the bolshoy ussuriysky island Wu Su cable- stayed bridge as the engineering background,and based on analysis of nonlinear theory and stability theory,by establishing detailed analysis of key parts components model,and study stability of beam on the cable tower anchorage zone and the local mechanical properties and the thin- walled box girder. The calculation results show that normal stress on the inner wall of the cable ducts appear stress concentration,which is along with the horizontal transverse to the cable tower anchorage zone,and tensile stress appears nearby,and the tensile stress value is 0. 638 MPa,less than the designed values.Roof and floor stress of cable girder anchorage zone are all small,the steel anchor box of local stress concentration is obvious,so the design should take full account of the stress concentration phenomenon of cable anchorage zone of anchor box,therefore,it is recommended to take anchor box stiffening partly to prevent the instability and failure of steel anchor box firstly. The steel box girder minimum stability coefficient is 6. 513,the overall and local stability meets the safety requirements.