基于性能抗震设计的钢筋混凝土柱试验研究

发布时间：2019-03-09 10:04

【摘要】：基于性能的抗震设计对于结构构件的能力需求不仅仅局限在极限承载力和弹性变形能力上，同时对结构构件延性变形、滞回耗能等抗震性能也有了明确的需求。根据性能设计要求进行结构构件设计，需要建立构件基本参数与抗震性能之间的数值关系。本文从国内外规范、试验研究、数值分析多个方面对钢筋混凝土柱截面延性、位移延性和塑性铰长度等抗震性能参数的影响因素、计算方法和统计概率分布等进行了分析与研究，其主要内容如下： 1.配箍率作为影响钢筋混凝土柱延性的一个主要参数，已经受到国内外学者和结构设计规范的关注。本文介绍了国内外主要规范对于钢筋混凝土柱最小配箍率的相关规定。计算对比了各国规范中最小配箍率对截面延性的影响。讨论了我国规范按照最小配箍率所能获得的柱截面延性，并对最小配箍率的设置提出了建议。 2.本文设计了4根钢筋混凝土悬臂柱，并对其进行了低周反复荷载试验。试验中主要测试内容是柱顶位移、箍筋应变。试验获得了在压弯作用下箍筋应变分布和变化情况，为柱截面混凝土所承受的约束应力计算提供了试验数据支持。同时通过变化轴压比、加载方式，讨论了这两个因素对柱抗震性能的影响。试验结果表明轴压比和加载方式对于柱破坏形态、箍筋应变分布影响显著。总结了箍筋应变在柱截面内沿环向分布规律和沿柱高度方向的变化规律。 3.对试验获得的箍筋应变数据进行整理分析，导入钢筋应力-应变全曲线，通过分析得到了柱试验过程箍筋应力分布和变化数据。从而得到箍筋约束的柱截面混凝土受到的约束力分布情况。根据Mander的约束理论，计算出有效约束系数，可以得到箍筋间弱约束截面的约束应力分布情况。通过引入混凝土膨胀参数，对约束应力进行计算，从而改进计算柱截面延性的纤维模型。利用改进的纤维模型，对影响截面曲率延性的各个参数进行了分析，并通过回归分析建立了截面曲率延性与配箍特征值、轴压比、纵向配筋率和核心混凝土面积比之间的关系。与其他基于性能的截面延性设计方法计算结果相比，，本文建议的方法准确度相对较高，能较好反映曲率延性系数的变化规律。 4.位移延性作为最基本的构件抗震性能指标，有众多的影响参数。按照Priestly的计算方法，可以采用两个主要参数来计算柱位移延性，分别是截面延性和塑性铰长度。本文从美国太平洋地震研究中心提供的柱试验数据中选取了143个滞回曲线完整且破坏形态为弯曲破坏的柱试验数据，通过计算分析得到柱等效塑性铰长度。再通过回归分析，获得了等效塑性铰长度的计算公式。经试验结果的验证，本文建议的公式具有较高的计算精度。本文收集了国内45个混凝土柱的抗震试验结果对本文建议的方法进行检验，结果表明采用本文建议的方法计算得到的位移延性均值与试验结果的均值基本一致，其误差基本能保证在20％以内，相对误差呈正态分布。 5.基于性能的抗震设防理念必然和不同地震作用下结构抗震性能指标相联系。而位移是最为直观的指标之一。通过对直接基于位移的抗震设计方法和基于性能的多目标抗震思想的研究，本文提出了基于位移的多水准抗震设计方法。这一设计方法首先根据业主的要求确定不同烈度地震作用下对结构位移性能的预期与需求。通过位移需求构造需求曲线，而结构的抗震性能将按照这一曲线，采用改进的直接基于位移的能力谱方法进行设计。采用一个单自由度桥墩的设计过程介绍了基于位移的多水准设计方法的设计流程。
[Abstract]:The performance-based seismic design is not only limited to the ultimate bearing capacity and the elastic deformation capacity, but also has a clear demand for the seismic performance of the structural members, such as the ductility deformation, the hysteretic energy dissipation and the like. According to the performance design requirements, the structural component design is carried out, and the numerical relation between the basic parameters of the component and the anti-seismic performance needs to be established. In this paper, the influence factors, the calculation method and the statistical probability distribution of the seismic performance parameters such as the section ductility, the displacement ductility and the plastic hinge length of the reinforced concrete column are analyzed and studied from the aspects of the domestic and foreign specifications, the test and the numerical analysis. The main contents of this paper are as follows: "Next:1. The stirrup ratio is a main parameter which influences the ductility of reinforced concrete column, and has been subjected to domestic and foreign scholars and structural design specifications." The paper introduces the phase of the minimum stirrup ratio for reinforced concrete columns at home and abroad. The cross-sectional ductility is calculated and compared with the minimum coupling ratio in national specifications. The influence of the criterion on the ductility of the column in accordance with the minimum stirrup ratio and the setting of the minimum stirrup ratio are discussed. In this paper, four reinforced concrete cantilever columns are designed, and it has been carried out for a low cycle. Complex load test. The main test contents in the test are the column top displacement And the strain distribution and the variation of the stirrup under the bending action are obtained, and a test is provided for the constraint stress calculation under the column section concrete. The data support of the column is also discussed through the change of the axial compression ratio and the loading mode, and the two factors are discussed. The experimental results show that the axial compression ratio and the loading method are different to the column failure mode and the hoop strain. The distribution of the hoop strain in the section of the column and the height direction of the column are summarized. 3. The strain data of the stirrups obtained by the test are analyzed and analyzed, and the stress-strain full curve of the steel bar is introduced, and the stress of the stirrups during the column test is obtained through the analysis. Distribution and variation of data to obtain a column section of concrete that is restrained by the stirrups. According to the constraint theory of the Mander, the effective constraint coefficient can be calculated, and the weak constraint cross-section between the stirrups can be obtained. In that case of stress distribution of the beam, the constraint stress is calculated by introduce the expansion parameter of the concrete, so as to improve the section of the calculation column. In this paper, a modified fiber model is used to analyze the various parameters which influence the ductility of the section curvature, and the ductility of the section curvature and the characteristic value of the hoop, the axial compression ratio, the longitudinal reinforcement ratio and the core concrete surface are established by the regression analysis. The accuracy of the proposed method is relatively high, which can reflect the curvature ductility better than the other performance-based design method of the cross-section ductility design. the variation rule of the coefficient.4. The displacement ductility is the most basic seismic performance index of the component There are many influence parameters. According to Priestly's calculation method, two main parameters can be used to calculate the displacement ductility of the column, respectively. In this paper, the column test data of 143 hysteretic curves are selected from the column test data provided by the Pacific Seismic Research Center of the United States, and the column test data in the form of bending and failure are selected by calculation and analysis. The equivalent plastic hinge length to the column is obtained. The equivalent plastic is obtained by the regression analysis. The calculation formula of the length of the sex hinge. The formula of this paper is verified by the verification of the test results. The results of the anti-seismic test of 45 concrete columns in China are tested. The results show that the mean value of the displacement ductility obtained by the method proposed in this paper is basically the same as that of the test results, and the error is basically the same as that of the test results. can be ensured to be within 20 percent, The relative error is a normal distribution.5. The anti-seismic fortification concept based on the performance must be under the effect of different earthquakes It is related to the seismic performance index of the structure. Moving is one of the most intuitive indexes. Based on the research of the anti-seismic design method based on displacement and the multi-objective anti-seismic idea based on performance, this paper puts forward the position based on bit The design method of the multi-level anti-seismic design is based on the owner's request to determine the alignment of the different intensity seismic action. The expected and demand of the structure displacement performance. The demand curve is constructed by the displacement demand, and the seismic performance of the structure will be based on this curve, and the improved direct-based position is adopted. The method of the capability spectrum of a single-degree-of-freedom pier is used to design a single-degree-of-freedom pier.
【学位授予单位】：湖南大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TU375.3;TU352.11

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