针对某大跨径π型叠合梁斜拉桥的气动性能，利用刚性节段模型针对其成桥状态展开了系统的风洞试验研究。试验结果表明，该桥主梁在设计风速范围内存在明显的竖弯及扭转耦合涡激共振现象，即使将竖弯以及扭转阻尼比提高到1%左右，仍然存在明显的涡激共振现象并且振幅超过规范限值。频谱分析表明，该桥主梁断面的竖弯和扭转耦合涡激共振的频率是一致的，其涡振“锁定”的频率接近竖向固有频率。探讨分析了主梁断面的弯扭耦合共振频率特性及成因。通过风洞试验对包括中央稳定板、边稳定板以及导流板在内的一系列气动减振措施进行了参数化的研究，并提出了最优的减振方案，有效抑制了该桥的涡激共振现象。研究成果可为类似桥梁断面涡激共振减振设计提供参考。

Aiming at aerodynamic performance of a long-span cable-stayed bridge stiffened with π-type composite girder, a rigid segment model was used to conduct systematic wind tunnel tests for the bridge completion state. Test results showed that the bridge main girder has obvious bending-torsion coupled vortex induced resonance within the range of designed wind speeds, even damping ratios of both vertical bending and torsion directions are increased to reach 1%, there is an obvious vortex induced resonance phenomenon and its amplitude exceeds the specification limit. Spectral analysis showed that the bridge main girder’s vertical bending natural frequency is consistent to its bending-torsion coupled vortex induced resonance frequency, the main girder’s vortex vibration “lock-in” frequency is close to its vertical bending natural frequency. The frequency characteristics and causes of bending-torsion coupled resonance of the main girder section were discussed and analyzed. Through wind tunnel tests, a series of aerodynamic vibration reduction measures including central stabilizer plate, side stabilizer plate and guide plate were studied from the point of view of parameterization, and the optimal vibration reduction scheme was proposed to effectively suppress the bridge’s vortex induced resonance phenomenon. The study results provided a reference for the design of vortex induced resonance vibration reduction of similar bridge sections.