抗风缆对大跨悬索桥颤振控制的有效性研究

Effectiveness of Storm Ropes for Long Suspension Bridge's Flutter Control

摘要:

对斜拉式抗风缆的不同张拉力以及不同锚固形式进行比较,考察了抗风缆对大跨悬索桥颤振控制的有效性.用简支弹性梁的Rayleigh方法和有限元计算频率的变化趋势,并在同济大学TJ-3建筑风洞中进行全桥气弹模型试验.结果表明,仅在中跨施加抗风缆就能显著提高桥梁结构的固有频率,但需注意抗风缆在悬索桥主缆上的锚固位置,这由于某些锚固位置有可能在施工的一些阶段引发更差的桥梁气动性能,建议在施加抗风缆颤振控制措施前先进行风洞试验研究.

Abstract:

The effectiveness of storm rope for long suspension bridge's flutter control is investigated by comparing different tension forces and anchoring positions.With finite element method(FEM) and Rayleigh method,the varied tendency of frequencies is examined,which is followed up by a full-scale aeroelastic model test in wind tunnel TJ-3 in Tongji University.The study shows a notable increase of natural frequencies of bridge just by applying storm ropes to the mid-span.However,special attention should be paid to the storm rope's anchoring position at the main cable,which would induce more instability of the structure during some certain periods of construction.Because of the complexity of this issue,it is strongly recommended that wind tunnel testing be conducted before the application of storm ropes.