双主跨悬索桥静风失稳模式及其机理分析

摘要

随着双主跨悬索桥的广泛应用和跨度的增大,需要研究其静风稳定性能,以确保桥梁的安全稳定运营.采用风荷载增量与内外迭代方法,编制相应分析程序,对三座结构体系不同的双主跨悬索桥静风稳定性进行非线性全过程分析.通过与单主跨悬索桥静风失稳形态及双主跨悬索桥自身失稳形态的比较,得到了双主跨悬索桥静风失稳形态的典型特征,重点提出并阐述了双主跨悬索桥的两种静风失稳模式——双侧反对称失稳模式和单侧非对称失稳模式,并详细探讨了这两种失稳模式的产生机理.%With the application of suspension bridges with double main spans,the aerostatic stability should be studied in order to maintain the safe operation.A procedure based on aerostatic load increment and double iterations was programmed and applied to analyze the aerostatic stability of three suspension bridges with double main spans.The characters of aerostatic instability for suspension bridge with double main spans were gained by comparing the instability modes between the suspension bridges with single and double main spans.There are two aerostatic instability modes for suspension bridge with double main spans,which include bilateral anti-symmetric instability mode and unilateral non-symmetric instability mode.Meanwhile,the mechanism of the two modes was discussed in detail.