【作者】 龚胡广；

【导师】 沈蒲生；

【作者基本信息】 湖南大学 ， 结构工程， 2006， 博士

【摘要】 高层钢框架-混凝土核心筒(墙)或高层劲性混凝土框架-混凝土核心筒(墙)混合结构,是近年来在我国迅速发展的一种新型结构体系。对于高层混合结构抗震性能的研究,是一项很重要的内容。目前,结构的抗震性能设计思想也由传统的基于力的强度设计方法发展到基于性能或位移的延性抗震设计方法。论文以国家自然科学基金项目“高层混合结构基本受力特性的研究”为依托,围绕基于性能的抗震设计方法,着重在以下几个方面进行研究工作:1.在高层混合结构静力推覆分析中,高阶振型对于结构的分析结果影响往往不可忽略。论文将模态推覆分析方法与用自适应的加载方式相结合,提出了一种改进的多模态静力推覆分析方法。该方法同时考虑了高阶振型以及加载时程性的影响。运用模态推覆分析将多自由度体系解耦成每阶模态对应的单自由度体系,对于每阶模态下的推覆分析,当结构进入塑性阶段后,采用自适应的加载方式,得到每阶模态下结构的反应。2.采用我国规范规定的剪切波速分类对场地土进行划分,对双线性单自由度体系在177条地震动记录下进行弹塑性动力时程分析。通过对理想双线性体系的均值弹塑性位移比与强度折减系数进行了统计分析与数值拟合,建立了两大类场地土(硬土、软土)下的μ- R - T回归公式。并详细分析了场地土情况、震级、震中距、阻尼以及结构滞回特性对弹塑性位移比的影响。3.评述了静力推覆分析方法中应用能力谱方法确定结构目标位移的应用情况。在我国抗震规范的弹性反应谱的基础上,结合不同场地土情况下得到的μ? R ? T回归公式,建立了基于等延性强度下的改进能力谱曲线。并在多模态静力推覆分析方法的基础上,对于每阶模态下的位移需求(目标位移),提出了应用改进能力谱方法求得结构位移需求的一般步骤。并首次将能力谱方法应用到混合结构抗震性能的评估中,对不同高度的混合结构进行了抗震性能的能力需求分析。4.采用Park-Ang损伤模型对不同高度的混合结构进行了损伤分析。对比了不同连梁的连接形式以及剪力墙设置水平缝情况下,结构整体损伤指标以及层间滞回耗能的分布。在此基础上,提出了改善混合结构抗震性能的措施。5.对长沙一已建的32层混合结构以及同济大学一混合结构缩尺振动台试验,进行了弹塑性动力时程分析与静力推覆分析。对比两种分析方法下楼层位移、层间位移角需求,近一步论证了本文分析方法在实际工程中的应用的可靠性。更多还原

【Abstract】 In China, tall building hybrid structures (TBHS), which are composed with steel frames and concrete core-tubes (shear-walls) or with composite steel frames and concrete core-tubes (shear-walls), have been widely applied. It is rational to research the seismic response of the TBHS. Presently, the seismic design has been shifted from force-based design to performance-based design or displacement-based design. In this thethis, combined with the research project“Research on the behavior of the tall building hybrid structure”financed by the Natural Science Foundation of China (NSFC), several key problems on performance-based design are studied.1. The higher mode effect cannot always be ignored in pushover analysis of tall building hybrid structures (TBHS). Therefore, in this thethis, an improved multi-mode pushover analysis, which combines the advantage of the modal pushover analysis (MPA) and the adaptive pushover analysis (APA), has been proposed to take the higher mode effect and history of load into account. In the multi-mode pushover analysis procedure, the multiple degree-of-freedom (MDOF) system can approximately be decomposed into equivalent single degree-of-freedom (ESDOF) system of multi-mode. The response of each modal pushover analysis can be attained by using adaptive load pattern when the structure enters into nonlinear stage.2.Nonlinear dynamic analysis of bilinear single degree-of-freedom (SDOF) system under 177 strong earthquake records which are classified by shearing wave velocities according to the China Code for Seismic Design of Buildings (GB50011-2001) is presented. Based on the comprehensive statistical analysis of inelastic displacement ratios, the regression equations ofμ- R - T about the strength reduction coefficient and inelastic displacement ratios are obtained. The effects of soil condition, earthquake magnitude, epicenter distance, damp ratios and hysteretic characteristics are considered in detail.3. The displacement demand (target displacement) of pushover analysis by adopting capacity spectra method is discussed. In this paper, based on the elastic spectra in GB50011-2001, an improved capacity spectra curve is developed by using the equations ofμ? R ? Tof different soil conditions. The displacement demand (target displacement) of each modal pushover analysis is obtained by using the improved capacity spectra method. The seismic response of different height TBHS are更多还原