大跨径三塔双主跨斜拉桥非线性风致静力失稳分析

摘要

Wind-induced static instability of long-span bridges cannot be ignored. The wind-induced static stability of a bridge under construction in China, which will be the longest cable-stayed bridge with three towers and two main spans in the world, deserves attention. On the basis of nonlinear wind-induced static instability theory of long-span bridges, and taking both load and geometric nonlinearity into consideration, its wind-induced static stability was analyzed by the improved incremental double iteration method . The special instability configuration of the bridge was described, with the effect and mechanism of cables, towers and auxiliary piers on the wind-induced static stability discussed. The mechanism of wind-induced static instability was also analyzed from the perspective of relation between wind load and structural rigidity.%大跨径桥梁的风致静力失稳问题不容忽视.我国一座建成后将是世界上跨度最大的三塔双主跨斜拉桥的空气静力稳定性值得关注.依据大跨径桥梁非线性风致静力失稳分析理论,考虑荷载非线性与几何非线性,采用优化的增量与内外两重迭代相结合的方法对该桥的空气静力稳定性进行了分析.描述了该桥特殊的失稳形态,讨论了拉索、桥塔和辅助墩对其空气静力稳定性的影响及机理,并从风荷载与结构刚度的关系解释了该桥的风致静力失稳机理.