聂利英, 郭其远, 李建中. 设置纵向大型液体粘滞阻尼器的大跨斜拉桥主梁纵向运动阻尼水平研究[J]. 工程力学, 2015, 32(9): 141-148. DOI: 10.6052/j.issn.1000-4750.2014.02.0119
引用本文: 聂利英, 郭其远, 李建中. 设置纵向大型液体粘滞阻尼器的大跨斜拉桥主梁纵向运动阻尼水平研究[J]. 工程力学, 2015, 32(9): 141-148. DOI: 10.6052/j.issn.1000-4750.2014.02.0119
NIE Li-ying, GUO Qi-yuan, LI Jian-zhong. LONGITUDINAL DAMPING LEVEL OF GIRDER MOTION OF LONG-SPAN CABLE STAYED BRIDGE WITH LARGE LONGITUDINAL FLUID VISCOUS DAMPERS[J]. Engineering Mechanics, 2015, 32(9): 141-148. DOI: 10.6052/j.issn.1000-4750.2014.02.0119
Citation: NIE Li-ying, GUO Qi-yuan, LI Jian-zhong. LONGITUDINAL DAMPING LEVEL OF GIRDER MOTION OF LONG-SPAN CABLE STAYED BRIDGE WITH LARGE LONGITUDINAL FLUID VISCOUS DAMPERS[J]. Engineering Mechanics, 2015, 32(9): 141-148. DOI: 10.6052/j.issn.1000-4750.2014.02.0119

设置纵向大型液体粘滞阻尼器的大跨斜拉桥主梁纵向运动阻尼水平研究

LONGITUDINAL DAMPING LEVEL OF GIRDER MOTION OF LONG-SPAN CABLE STAYED BRIDGE WITH LARGE LONGITUDINAL FLUID VISCOUS DAMPERS

  • 摘要: 大跨斜拉桥减震耗能的一种典型应用是塔梁间设置纵向大型液体粘滞阻尼器,其参数选取以有效率的限制地震荷载作用下的主梁纵向位移以及改善主要构件地震力为目标。大跨斜拉桥的一阶纵飘振型处于长周期,远离场地卓越周期,此时主梁纵向位移响应对阻尼水平的增加不敏感。此种设计思路很可能导致阻尼器设计参数过大,从而为主梁纵向运动提供过大的阻尼水平。基于现有研究,采用单自由度评价模型及相应的等效阻尼比为评价参数。以某大型斜拉桥为典型工程实例,以全桥模型有限元分析与单自由度评价模型地震反应分析对比验证评价模型的可靠性,并以等效阻尼比和主梁纵向自由振动揭示塔梁间设置大型FVD为主梁纵向运动提供了超高水平阻尼比的现象。此种应用突破了FVD常规应用中的附加阻尼比界限,也改变了主梁的动力边界条件。

     

    Abstract: A typical application in seismic design of energy dissipation is the installation of longitudinal large fluid viscous dampers (FVDs) between pylons and girders. The determination of parameters of FVDs is based on the optimal effects of longitudinal displacements of girders and seismic forces of the bridge key components. The fundamental period of girder longitudinal sway motion is long and far away from the site predominant period because the long-period compositions in seismic wave are scare. Therefore, the longitudinal seismic girder displacement is insensitive to damping increase and the determination of the FVDs’ parameters might lead to much too high damping level of girder longitudinal movement. Based on present researches, the estimation model of single degree of freedom (SDOF) and corresponding estimation parameter are put forward. Taking a long-span cable stayed bridge as example, the reliability of the SDOF estimation model is verified through a comparison with the whole bridge model. Further, the too much high damping level of girder longitudinal movement caused by FVDs is explained by the calculated using the estimation model and free vibration results of the whole bridge model. The damping level of girder longitudinal movement is so high that it exceeds the damping limitation of conventional use of FVDs and changes the dynamic boundary of the girder.

     

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