非对称组合梁斜拉桥转体施工敏感性分析

摘要:

为研究影响非对称组合梁斜拉桥转体施工结果的具体因素，以某非对称钢混组合梁斜拉桥为研究背景，采用有限元软件对其进行参数敏感性分析，重点研究施工支架刚度、斜拉索初始张拉力以及平衡配重对结构施工过程内力和线形的影响。结果表明：1）支架刚度对斜拉桥落架后的主梁内力影响很小；2）增大初始张拉力能够减小主梁跨中处的弯矩，但同时会增大塔根处主梁的弯矩，适当调整初始张拉力可以减小主梁脱离支架后的位移以及两侧中跨悬臂端位移差；3）过大的配重线极度会增大边跨负弯矩，可能成为控制设计的因素，但适度的配重重量可以减小主梁跨中悬臂端的下挠。

Abstract:

To study the specific factors affecting the swing construction results of asymmetric composite beam cable-stayed bridge, an asymmetric steel-concrete composite beam cable-stayed bridge is taken as the research background. The parameter sensitivity analysis is carried out by using finite element method, focusing on the effects of bracket stiffness, initial tension force of cables and the balance weight on the structure force and alignment of bridge during construction. The results show that: 1) the bracket stiffness has little effect on the internal force of the composite beam of the cable-stayed bridge; 2) Increasing the initial tensioning force can reduce the bending moment at the mid span of the beam, it also increase the bending moment of the beam at the tower root. Properly adjusting the initial tensioning force can reduce the displacement of the beam after it is separated from the support and the displacement difference between the asymmetric cantilever ends in the mid span on both sides; 3) Excessive counterweight will extremely increase the hogging bending moment in the side span, which may become a controlling factor of the design, but appropriate counterweight weight can reduce the downward deflection of cantilever end in the middle of main beam span.