沌口长江公路大桥弹性—阻尼复合式减震装置的应用

Application of a New Type of Elasticity-damping Composite Damping Device on Zhuankou Yangtze River Highway Bridge

国内部分斜拉桥采用传统液体黏滞阻尼器,一段运营期后,梁端累积位移过大,导致伸缩缝破坏,将对桥梁纵向变形与行车安全产生不良影响。为了解决这一问题,本文结合沌口长江公路大桥减震设计,提出了一种新型的弹性—阻尼复合式减震装置,即在传统阻尼器上增加弹簧装置,使其具有弹性复位功能。本文采用有限元分析软件MIDAS,建立沌口长江大桥空间模型,利用MIDAS提供的粘弹性消能器的Maxwell模型模拟该减震装置的本构关系,分析其阻尼参数与弹簧参数的变化对大桥动力和静力性能的影响。分析结果表明,通过调整阻尼参数与弹簧参数,该装置能有效减小地震作用效应、控制梁端纵向位移,并能提高塔柱第二类稳定性和降低主塔、主梁、斜拉索的应力幅,从而提高全桥耐久性。

Parts of cable-stayed bridges, which adopt the traditional liquid viscous dampers, produce excessive beam-end displacements alter a period of operation, resulting in the failure of the expansion joints, and affect the longitudinal deformation of the bridge and driving safety adversely. This paper proposes a new type of elasticity-damping composite device for the seismic design of Zhuankou Yangtze River Highway Bridge for this problem, in which a mechanical spring is added to the traditional damper to make it elastically reset. This paper adopts MIDAS program to model the Zhuankou Yangtze River Bridge, analyzing the influenees of the changes in damping parameters and spring parameters of the damping device on dynamic and static performance of the bridge with simulating the constitutive relationship of the damping device using the Maxwell model of the viscoelastic energy absorber provided by MIDAS. The results show that the device can effectively decrease the seismic effects by adjusting damping parameters and spring parameters, the longitudinal beam-end displacements, and solve the second eategogy of stability problem of the pylons, the stress amplitudes of the pylons, girders and stay cables, thereby improving the durability of the whole bridge.