【作者】 门进杰；

【导师】 史庆轩；

【作者基本信息】 西安建筑科技大学 ， 结构工程， 2007， 博士

【摘要】 随着基于性能抗震设计理论逐步被地震工程界所认同，对其研究已成为当前地震工程界的热点。该理论以结构抗震性能分析为基础进行设计，可充分发挥工程师的主动性，是设计理念上的一次变革，开展这方面的研究对工程结构的抗震设计具有重大的意义。本文围绕不规则钢筋混凝土结构基于性能的抗震设计与方法进行了以下几个方面的研究工作。针对我国现行抗震规范中，地震作用水平从多遇地震到罕遇地震的超越概率相差较大的现状，提出一中小震的概念，从而形成“四水准”的设防目标。在统计分析大量国内外钢筋混凝土柱试验数据的基础上，建立了结构在地震作用下处于暂时使用和修复后使用性能水平的量化指标。通过计算分析，表明按现行规范“小震不坏”进行设计的结构，不一定能保证“中震可修”，而按照本文提出的“中小震”进行结构抗震设计，可以保证“中震可修”。通过单自由度的动力方程，以屈服承载力系数ζ_y为参量，建立了基于延性系数的弹塑性需求曲线方程，通过单自由度体系的计算分析，得到等ζ_y延性需求谱和等延性ζ_y谱，提出了基于等ζ_y延性需求谱的结构抗震性能评估方法。通过计算分析，结果表明该方法可以有效的对工程结构的抗震性能进行评估。在分析总结几种常见的非线性静力分析侧向力分布形式的基础上，提出两个基于多自由度体系振型的侧向力分布计算方法：30％方法和部分SRSS方法。针对竖向不规则结构的特点，考虑框架结构层间侧向刚度的影响，对传统的水平侧向力分布进行了修正，提出了改进的水平侧向力分布形式。通过计算分析，结果表明本文所提出的侧向力分布模式可以较好的用于刚度发生突变时竖向不规则框架结构的非线性静力分析。考虑结构在地震作用下不同反应阶段的动力特性，根据结构的振型分析，按照结构在不同地震作用水平时的性能要求，采用振型反应谱法，建立起结构在不同地震作用水平下的弹塑性需求曲线族，即结构的层间剪力—层间位移需求曲线，提出了以各楼层为研究对象的层间能力谱法。通过计算分析，结果表明层间能力谱法可以有效的用于对竖向不规则结构进行基于性能的抗震设计和评估，并能控制结构在不同地震作用下的变形性能、塑性铰出现顺序及部位，与时程分析方法相比偏于保守，且比直接基于位移的设计方法具有明显的优势。针对平面不规则结构地震作用的分布特点，提出了4种非线性静力分析的水平侧向力分布计算方法：二次分配法、分层法、动力偏心法和动力分层法，从而实现平面不规则结构的非线性静力分析。通过计算分析，结果表明本文所提出的水平侧向力分布模式可较好地用于平面不规则框架结构的非线性静力分析，所得到的塑性铰分布、层间侧移角等与时程分析结果符合较好。从现行规范对平面不规则结构的限制条件出发，推导出了结构层间扭转角与扭转位移比的关系式，结合框架结构在不同性能水平下的层间侧移角限值，建立了平面不规则框架结构在不同地震作用水平下的扭转角需求曲线，提出了扭转角能力谱法。计算分析表明，按照本文所提出的扭转角能力谱法可方便有效的对平面不规则框架结构进行基于性能的抗震评估和设计。地震易损性分析与基于性能的抗震设计理论相结合，可以更为全面和系统地对结构的抗震性能进行评估。考虑不同的单元模型和恢复力模型，选取40条实际地震加速度记录，形成了120个结构体系—地震动系统样本。分别选取竖向不规则框架薄弱层的层间侧移角和平面不规则结构的最大层间扭转角为易损性变量，通过对系统样本进行非线性动力分析和回归分析，提出了不规则框架结构易损性曲线的建立方法。计算分析表明，利用本文建立的易损性曲线可方便有效的对不规则钢筋混凝土框架结构的抗震性能进行评估。更多还原

【Abstract】 Performance based seismic design (PBSD) theory is recognized step by step in earthquake engineering field, and the research about it is becoming a principal topic. PBSD is a seismic design innovation, which is on the basis of seismic performance analysis of structures and can exert the subjective ability of the engineer adequately. Therefore research on PBSD has important value for seismic design of practical structures. Centering round theory and methods of performance based seismic design for irregular reinforced concrete frame structures, this dissertation involves the following work.The gap in probability of exceedance between frequent earthquake and extremely rare earthquake is very large in china seismic design code, therefore, a new definition of occasional earthquake is bring forward to form a four level seismic fortification criterion. Based on the statistical data of seismic performance test of RC columns, two index of temporarily operational and reparably operational performance levels are put forward. Examples are presented to demonstrate that buildings satisfied the fully operational level under frequent earthquake is not ensure to be in temporarily operational level or reparably operational level under rare earthquake. If the frequent earthquake is substituted by the occasional earthquake, the problem above can be solved well.Based on the dynamical equation of single degree of freedom, a parameter of yield strength coefficientζ_y is introduced to deduce the dynamical equation of ductility coefficient. Then the ductility demand spectrum, which comprises a group of ductility coefficients or yield strength coefficient versus natural period curves for different yield strength coefficient or ductility coefficients are obtained. Based on the pushover analysis, a new performance-based seismic evaluation method, constantζ_y ductility spectrum method is established. Examples are presented to demonstrate the applicability and utility of the proposed methodology.Based on the summarization and research of conventional lateral load patterns for nonlinear static analysis, two methods based on the modes of MDOF, which are called 30% rule method, partial SRSS rule method, are established to calculate the lateral load for pushover analysis. Considering the story stiffness, a new improved lateral load distribution is established for vertically irregular building structures. Examples are presented to demonstrate the applicability and utility of the proposed methodology.The deformation of vertically irregular frame structures under earthquake is vary different to that of regular frame, thereby, a new method named Inter-Story Capacity Spectrum is put forward for the PBSD of vertically irregular frame structures. The new method can be used to design a vertically irregular frame considering different performance level under different earthquake hazard level, at the same time the modal of structures, the spectrum of seismic design code are taken into account. Also the Inter-Story Capacity Spectrum method can be used to evaluate the seismic performance of vertically irregular frame structures. Examples are presented to demonstrate the applicability and utility of the proposed methodology.Based on the research of the torsion effects caused by the earthquake load, four methods calculated the lateral load distribution for asymmetric structures are established. They are two-times distribution method, storied distribution method, dynamic eccentricity method and dynamic storied distribution method. Examples are presented to demonstrate that the pushover results including the distribution of hinges, inter-story drift ratio and inter-story torsion angle, used the four methods are coincidence well with that of nonlinear time history analysis.The relationship between inter-story torsion angle and torsion deformation ratio is deduced base on the rule of irregular plan structures in China tall building technical specification. Considering the inter-story ratio limitation of different performance levels under different earthquake hazard levels, a series of torsion angle demand curves are established and a new method named as Torsion Angle Capacity Spectrum is put forward for the PBSD of irregular plan frame structures. The method also can be used for the performance based seismic evaluation of irregular plan structures. Examples are presented to explain the method principle and to demonstrate the applicability and utility of the proposed methodology.Considering different unit model and different hysteretic model, selecting forty earthquake records, one hundred and twenty structure-earthquake system samples are obtained for RC irregular frame. Selecting the weakness story inter-story drift ratio and the maximum torsion angle respectively, through the nonlinear dynamic analysis and linear regress, a new fragility analysis method is put forward for vertically irregular frame and irregular plan structures. Examples are also presented to demonstrate the applicability and utility of the proposed methodology. It is concluded that fragility analysis can be used together with the performance based seismic evaluation method, which is conduced to realize the seismic performance of buildings accurately and systemically.更多还原