大跨度悬索桥吊索减振技术研究与应用

针对大跨度悬索桥吊索频率低、阻尼小、以致容易发生风振的弱点，以舟山西堠门大桥的长细吊索风振问题为工程背景，研究了其抗风减振方法．首先通过环境激励法确定了吊索的动力特性.然后基于理论分析和风洞试验确定了分隔器减振方案，并对不同分隔器数量时的减振效果进行了对比研究.最后通过某大风天气下有无分隔器的两组吊索的实测数据结果对比验证了分隔器减振方案的有效性.试验和实测结果表明：安装分隔器后吊索的碰索现象不再发生，吊索的各阶振动均明显减小，各阶减振率达55%～95%．
The hanger cables of long-span suspension bridges are susceptible to wind-induced vibration as they have low natural frequencies and low mechanical damping. In this paper, the wind-induced vibration problem of the hanger cables of Xihoumen Bridge was investigated to research the vibration control method. Firstly, the dynamic characteristics of the hanger cables were obtained by environmental incentive method. Then, the scheme of installing spacers was determined by theoretical analysis and wind tunnel experiments, in addition, the influence of the number of spacers on vibration-reduction efficiency was investigated in the experiments. Finally, according to the field test of the wind-induced vibration of two hanger cables with and without spacer respectively conducted in strong wind weather, the results indicates that after installation of the spacers, the collision phenomenon between the strands is eliminated. Moreover, the vibration of different modes of the hanger cable is significantly reduced by 55%～95%.