改善悬索桥施工阶段颤振稳定性的架设方法研究

大跨径悬索桥施工阶段尤其是施工初期的颤振稳定性是建设过程中面临的重要问题 ,它将受到主梁架设方法的重要影响。以宜昌长江大桥为工程背景 ,运用多模态颤振分析方法 ,分析了不同主梁架设方法下颤振临界风速的变化趋势。分析结果表明 :主梁采用非对称架设和从桥塔向跨中对称架设的方法可以有效地提高悬索桥在施工阶段尤其是施工初期的颤振稳定性

Study on Erection Sequence for Improving Flutter Stability of Suspension Bridges During Erection

The aerodynamic instability of long span suspension bridges is a serious engineering concern during erection particularly in the early erection stage. Its characteristics are significantly influenced by the sequence of the deck erection. By taking the Yichang Suspension Bridge over Yangtze River as example, the flutter stability with the deck erected by different sequence and non symmetrical sequence is detemined by the multi mode flutter analysis. The evolution of flutter speed with different deck erection sequence is also discussed. It is found out that the erection program from pylons to midspan and the non symmetrical erection sequence are aerodynamically favorable for the deck erection of long span suspension bridges particularly in the early erection stage.