斜拉桥斜拉索杠杆质量阻尼器减振技术研究

Study of Vibration Damping Technique of Using Lever Mass Dampers to Stay Cables of Cable-Stayed Bridges

为有效抑制大跨径斜拉桥斜拉索可能发生的大幅振动,在常规粘性剪切型阻尼器的基础上,研发了斜拉索杠杆质量阻尼器,通过杠杆放大作用,为斜拉索提供有效的附加阻尼、附加质量和附加刚度,共同抑制斜拉索的振动;推导出杠杆质量阻尼器对斜拉索的振动控制理论分析模型。以主跨688m的象山港大桥为例,对斜拉索阻尼器进行设计并应用于实桥。理论分析结果与实桥斜拉索振动测试结果表明,安装该阻尼器后,斜拉索最终的阻尼对应的对数衰减率基本在4%以上,可有效抑制斜拉索的振动。

To effectively prevent the occurrence of large-amplitude vibration on the stay cables of long-span cable-stayed bridges, the lever mass dampers for stay cables are developed on the basis of the common viscous shearing dampers. The lever mass damper can, via the lever amplification effect, provide effective additional damping, mass and stiffness to the stay cables, and participate in the vibration damping of the stay cables. The analytical model based on the vibration control theory of the lever mass dampers to the stay cables was derived. The Xiangshangang Bridge which has a main span of 688 m was taken as the study background. The stay cable dampers were designed and applied to the real bridge. The theoretical analysis results and the measured stay ca- ble vibration results of the real bridge indicated that after the dampers were installed, the logarith- mic decrement ratio related to the final stay cable damping basically maintained above 4 %, proving that the dampers could effectively absorb the vibration of the stay cables.