石首长江公路大桥斜拉索杠杆质量阻尼器应用研究

石首长江公路大桥主桥为主跨820 m的双塔六跨连续不对称空间双索面混合梁斜拉桥,最长斜拉索长约440 m,在外部激励作用下极易发生面内、外振动。针对石首长江公路大桥斜拉索的振动特性,在常规阻尼器的基础上进行构造优化设计,研发了一种双杆倒Y形连接杆斜拉索杠杆质量阻尼器,具有景观协调性好、横向连接刚度大、减振效果好等优点。通过对阻尼器的安装质量进行严格控制,安装位置比控制为2.23%~2.83%,使阻尼器达到了良好的减振效果,实测斜拉索阻尼对数衰减率均在3%以上,满足大桥斜拉索减振要求。

Study of Applying Lever Mass Dampers for Stay Cables of Shishou Changjiang River Highway Bridge

The main bridge of Shishou Changjiang River Highway Bridge is a two-pylon hybrid girder cable-stayed bridge.The bridge has six spans,with the main span of 820 m.The stay cables are arranged in asymmetrical spatial double cable planes and the longest stay cables reaches 440 m,which are prone to in-and-out of plane vibrations under external excitations.A type of inversed Y-shaped lever mass dampers that contains two connection bars are bespoke for the stay cables of the bridge,based on the structural optimization of conventional dampers,which can well merge with the surroundings,offer big transverse connection stiffness,and provide good vibration suppression effect.The installation of the dampers was strictly controlled,and the installation height ratios were controlled within the range of 2.23%to 2.83%,ensuring that the dampers could give full play to their damping effect.The measured damping logarithmic decrements of the dampers were all above 3%,meeting the vibration suppression requirements of the stay cables.