【作者】 任俊超；

【导师】 张其林；

【作者基本信息】 同济大学 ， 结构工程， 2007， 博士

【摘要】 大跨空间斜拉结构是一种新型的悬索杂交结构，主要由刚性结构和柔性索组合而成。伴随着其在公共建筑中的广泛应用，此类结构的力学性能，特别是抗震性能受到关注。另外，现行的建筑抗震规范并未涉及到关于大跨结构的明文规定，制约了斜拉结构的抗震研究发展。基于此，本文选取典型的三个斜拉工程，即郑州国际会展中心展厅钢屋盖、东海大桥桥头堡、江宁体育中心体育场看台顶蓬，系统研究了结构在多遇地震和罕遇地震下的动力响应。旨在掌握大跨空间斜拉结构的抗震性能，为抗震规范的进一步修订提供参考依据，为实际的抗震设计提出建议。首先，采用模态分析，探讨斜拉结构的自振特性和结构参数对动力性能的影响。其后，考虑几何非线性和预应力效应，在遭遇多遇地震的情况下，选取振型分解反应谱和弹性时程方法，进行质量参与系数的取值分析，组合方法的比较分析，反应谱参数分析。此外，分析算例在一维地震作用和多维地震作用下的动力反应，得到结构的整体变形图、轴力分布图和弯矩分布图，以及各组成部分的内力最大值、控制点的位移时程曲线。再次，在罕遇地震下，考虑结构的几何非线形和预应力效应，考虑材料塑性，采用弹塑性时程分析，计算沿主跨方向的水平强震作用下以及竖向强震作用下的位移最值、应力最值和控制点位移时程曲线。最后，分别比较分析算例在遭遇多遇地震时的振型分解反应谱法和弹性时程分析法、遭遇罕遇地震时的弹性时程分析和弹塑性时程分析的内力、位移和控制点位移最值；根据上述研究，得出以下主要结论：(1)斜拉结构的动力性能复杂，高阶振型贡献不可忽略。(2)预张力值的改变不影响结构的力学性能，而边界条件的改变影响结构的力学性能。(3)不同抗震方法的选取均能得到斜拉结构的固有动力特性。(4)在多遇地震作用下，斜拉结构的应力水平较低，仍处于弹性阶段。应首选弹性时程分析进行计算分析。(5)在强震作用下，斜拉结构仍处于弹性工作阶段，未发生塑性变形。因此可不考虑材料塑性对其产生的影响。(6)罕遇地震初期的强烈冲击导致斜拉结构产生过大的变形，且达到应力幅值，对斜拉结构的动力破坏起着重要的作用。更多还原

【Abstract】 The large-span spatial cable stay structures composed of rigid structures and flexible cables is one new type of cable hybrid structures. With the wide application of cable stay structures in public buildings, mechanical properties are concerned, especially seismic properties. In addition, the express provisions about large-span structures are not involved in actual structural seismic code of China, which may confine the development of seismicresearch and design.Based on above all, three cable stay engineerings including the steel roof of Zhengzhou International Conference and Exhibition Center, the bridge tower of Donghai Bridge and the stadium ceiling of Jiangning Sports Center Stadium are adopted as subjects investigated in this paper. Furthermore, dynamic responses of the cable stay structures under small earthquake and intensive earthquake are explored to hold seismic properties of large-span spatial cable stay structure, to offer references for further revises about seismic code and to put forward suggestions for actual seismic design of cable stay structures.First, modal analysis on three examples is carried out to discuss self-vibration properties of cable stay structures and effects of structural parameters on dynamic performances.Thereafter, geometry nonlinearity and pre-tensions are considered in analysis, response spectrum method and elastic time-history method is respectively introduced to research under small earthquake. Mass fraction analysis, comparative analysis of combination methods and response spectrum dynamic analysis on structural parameters are carded out. Besides, dynamic responses of calculation examples are analyzed under one-dimension and many-dimensions earthquake action. Thus, the whole distortion figures, axial force figures and moment figures as well as the maximums of structural parts and displacement time-history curves of reference points. Afterwards, under intensive earthquake, geometry nonlinearity and pre-tensions as well as material plasticity are considered in analysis. Elastic-plastic time-history method is used to calculate the displacement maximums, stress maximums and displacement time-history curves of reference points under horizontal and vertical earthquake respectively.At last, results including maximums of internal forces, displacements and reference points of response spectrum method are compared with those of elastic time-history method under small earthquake. And, results including maximums of internal forces, displacements and reference points of elastic time-history method are compared with those of elastic-plastic time-history method under intensive earthquake.Main conclusions are obtained according to above analysis.(1) The cable stay structures are provided with complex dynamic performances so that the contribution of high modes is not ignored.(2) Effects of changes about pre-tensions may not affect structural performances, but effects of changes about boundary conditions do.(3) Different seismic analysis methods are selected to get inherent dynamic performance.(4) Stress values of cable stay structures are small under small earthquake so that the materials are in the elastic phase. Furthermore, it ought to choose elastic time-history method at first to do analysis.(5) The materials of cable stay structures are still in elastic phase under intensive earthquake so that plastic deformations don’t happen to the structures. Thus, material plasticity may not be considered in analysis.(6) The intensive impact of earlier intensive earthquake can result in large deformation of cable stay structures, which can play an important role in dynamic damages.更多还原