【作者】 宗雪梅；

【导师】 周绪红； 狄谨；

【作者基本信息】 长安大学 ， 桥梁与隧道工程， 2014， 博士

【摘要】 本文在总结国内外抗震研究成果及相关规范的基础上，结合我国多层立交结构建设实践，采用多级设防思想和弹塑性纤维模型分析法，通过理论公式推导和有限元数值分析，对城市多层立交结构的抗震设防水准、抗震性能水平和目标、塑性铰、延性能力及抗震设计计算方法进行研究，主要完成以下工作：以国内外抗震研究成果及相关规范为基础，考虑我国目前的经济状况及与现行规范的衔接，通过分析归纳等方法，对城市多层立交结构提出5级抗震设防水准，并给出每一等级下构件灾害状态；将城市多层立交桥梁按照重要性分类，提出不同类型结构的性能目标矩阵及抗震设防水准所对应的性能目标图，方便在实际工程中参考应用。采用有限元非线性时程分析方法，研究多层立交桥梁上下部结构14种连接形式、竖向4种地震波荷载分量及4种阻尼比大小等因素对结构自振特性、顺桥向及横桥向地震响应的影响，得出其地震力响应特征规律；结合实际工程经验公式及规范要求，从结构振型取用、支座形式设置、伸缩量确定、墩柱弹性阶段“双控目标”的确定、阻尼比及竖向分量选取等6个方面对多层立交结构动力响应进行分析，并给出抗震设计建议。采用弹塑性纤维模型分析法，考虑动轴压、主梁刚度及高阶振型耦合效应的影响，研究多层立交桥梁主要构件的塑性铰出铰顺序、随时间的发展变化、结构耗能能力、塑性铰转角大小及时程变化、墩顶位移、截面实际破损状态及破损状态与其余指标的对应关系等。在此基础上，通过理论分析，提出利用截面曲率作为多层立交结构墩柱延性性能指标来定量描述截面破损状态的方法。基于常见的截面破损模型，结合多层立交结构延性性能特征，根据平截面假定及力的平衡原理，推导了材料应变与曲率系数的关系公式；通过建立结构抗震性能水准与曲率系数的联系，推导了曲率系数与性能水准的定量关系公式；并提出利用曲率系数定量表示截面破损指标的方法；在此基础上，进一步建立基于曲率延性系数的截面破损指标与性能水准关系公式。采用前文推导公式以及几何加权分配思想，将构件截面破损指标进行权重分配，建立基于曲率延性系数的单个构件及整体结构损伤程度的模型，并利用此模型分析了多层立交结构单个构件及整体结构延性性能。在建立结构整体破损指标的基础上，提出基于曲率延性系数的结构弹塑性阶段设计方法及详细流程；结合现行城市桥梁抗震规范，系统地提出一套基于性能的多层立交结构抗震性能设计方法。更多还原

【Abstract】 Based on the summary of seismic research at home and abroad, multi-level fortificationwas adopted to discuss the seismic performance level and performance goals, as welll asmultilayer seismic fortification level city overpass structure. Then, the finite element methodand fiber model analysis method was adopted to conduct the research to the typical multilayeroverpass structure of plastic hinge and ductility capacity and other realtive designationproblems. a set of suitable forcity multi-level interchange structure seismic design based onperformance evaluation methods about the sectional curvature ductility coefficient as designparameters was systematically established. main studied results are listed as follows:Based on standard and the research results at home and abroad, the current economicsituation of our country and the existing norms of especially "cohesion" code for seismicdesign of Bridge City was considered, the city multi-level interchange structure seismicfortification levels5and seismic performance levels was proposed, the component disasterstatus of each level was gaved; the city of multilayer interchange bridge in order ofimportance are divided into4categories, the performance goal graph corresponding todifferent types of structural performance objective matrix and seismic fortification level wasalso proposed, it is sensible to easy reference in practical application.The time-dependent analysis method of the finite element software ANSYS was adoptedto study the multilayer overpass structure form of support and vertical seismic wavecomponent values and the values of damping ratio and other factors on the structure vibrationcharacteristics and the longitudinal and transverse direction of the bridge seismic response,the conclusion was drawed. The experience formula and specification requirements wascombined to give a ideal designation suggestion for selection of the multi-level interchangestructure dynamic response analysis in the vibration modes of the structure, and bearing typesetting, and expansion amount determination, and pier column elastic stage "double control",and damping ratio, and vertical component selection are given in6structural seismic.The fiber model of elastoplastic time history analysis method was adopted, and theinfluence of axial pressure and the girder stiffness and high order mode coupling effect of thebridge pier was considered, the plastic hinge position and range of variation with time wasstudied, the plastic hinge mechanism and development of the distribution diagram waspresented. On the basis of the research for the multi-level interchange energy dissipation ability and plastic hinge rotation and displacement and the section actual damage state and thecorresponding relations, the sectional curvature ductility index was presented to describe thestate of the damaged section method.Based on summary of the common damage model, relationship with multi-levelinterchange structure characteristics of stress and strain and curvature coefficient wascombined, according to the section force equilibrium principle and relation formulas, themulti-level interchange structure using curvature coefficient quantitative performancestandard formula was deduced, and section curvature ductility coefficient based on the saiddamage index and performance levels was further established.The damage index of the geometric average weighted distribution idea was adoted to putforward the curvature ductility factor for the individual components and the overall structureof the degree of damage model.Based on the whole damage index, the stage design method of elastic plastic structurescurvature ductility coefficient and detailed process was presented; the current standard wascombined to put forward a set of seismic-resistant design method for the seismic performanceof multilayer overpass structure performance, the basic principles including the content anddetailed procedures was expounded, it is for later use reference seismic multi-levelinterchange structure designation.更多还原