大跨悬索桥尖顶型主缆施工对猫道静风稳定性的影响

The Influence of Spire-type Main Cables of a Long-span Suspension Bridge on Aerostatic Stability of Catwalk during Construction

在大跨径悬索桥施工期间,主缆与猫道间存在气动干扰效应,施工期主缆易发生驰振失稳,猫道易发生静风失稳。为了同时保证施工期主缆和猫道的稳定性,以某大跨径悬索桥施工期尖顶型主缆和猫道为背景,采用能够保证施工期主缆驰振稳定性的猫道参数设置方法,利用流体力学软件Fluent和有限元软件ANSYS数值研究了考虑施工期尖顶型主缆影响的猫道三分力系数和静风稳定性。结果表明:主缆施工期不同工况对猫道三分力系数影响较大;猫道静风失稳临界风速随着尖顶型主缆的施工先变小后增大,在成桥阶段又变小;主缆的不同施工顺序既影响主缆施工期的驰振性能又影响猫道静风稳定性,施工时要统筹考虑。

There is aerodynamic interference effect between spire-type main cable and catwalk of a long-span suspension bridges during construction.Studies have shown that the main cable is easy to occur galloping instability and catwalk is prone to occur static wind instability.In order to ensure the stability of main cable and catwalk during construction,the spire-type main cable and catwalk of a long-span suspension bridge under different working conditions during construction are selected as the research object.The setting method of catwalk parameters which can ensure galloping stability of main cable during construction is used.And the method of numerical simulation with CFD software FLUENT and finite element software ANSYS are used to study the three-component coefficients and static wind stability of catwalk during construction of spire-type main cable.The results indicate that the spire-type main cable in different construction conditions has a greater influence on the catway.With the construction of spire-type main cable,the critical wind velocity of instability reduces,and then it will increase.Different construction sequence of spire-type main cable can affect both galloping performance of main cable and wind stability of catwalk during construction,both of those should be comprehensively considered during construction.