地震损伤钢筋混凝土构件修复加固试验及数值模拟

发布时间：2018-05-29 03:05

本文选题：钢筋混凝土 + 地震损伤　；参考：《天津大学》2014年博士论文

【摘要】：我国现行《建筑抗震设计规范》(GB50011-2010)及老版本规范均明确规定“小震不坏、中震可修、大震不倒”的抗震设防目标,对于“中震可修”情况,如何采取合理有效、施工方便的修复加固技术是工程中须重点解决的问题。钢筋混凝土梁柱是框架结构的重要组成部分,其在中度水准地震作用下存在较高的破坏风险,且经大量地震灾害分析表明,建筑结构地震损伤破坏往往集中在构件端部,对其加固性能等的研究尚不充分。本文通过试验研究、数值模拟及理论分析,研究损伤、加固后的钢筋混凝土柱和梁端试件抗震性能、受力特性及加固构造措施,为我国建筑抗震设计规范和混凝土结构加固规范的修订提供试验和理论基础,主要工作及成果包括:1)设计并制作6根钢筋混凝土柱试件及6根钢筋混凝土梁端试件。其中2根柱试件及2根梁端试件一次性加载至破坏,采集试验数据作为对比试件。其它试件进行损伤后加固。第一步对原试件进行低周往复损伤试验;第二步对损伤试件进行碳纤维加固和钢板加固,再对加固试件进行低周往复试验。柱试件的变化参数为轴压比与加固方式、梁端试件的变化参数为纵向钢筋配筋率与加固方式,研究分析试件的滞回性能、骨架曲线、耗能、延性、刚度退化及破坏形态等抗震性能。试验结果表明,轴压比小的加固柱试件较轴压比大的加固柱试件耗能高;采用碳纤维布加固后的受损梁端试件可以有效抑制塑性铰延展及混凝土的脱落破碎,表现出较好的承载力、耗能能力及延性等抗震性能。2)受损试件的数值模型参数确定是建模分析的难点,本文提出了基于截面刚度退化系数的“截面等效刚度”方法与基于混凝土强度损伤系数的“截面承载力等效强度”方法,通过简化分析,并将其用于试件数值模拟关键参数的确定,结合采用ANSYS有限元程序,对不同方式加固的试件进行数值建模分析,结果表明,数值分析结果与试验结果吻合较好,进一步验证了本文所建模型与关键参数确定的合理性和可信性。3)试验结果表明,加固后的柱试件与梁端试件承载力得到不同程度的提高,文中建立了钢筋混凝土损伤加固柱试件斜截面受剪承载力计算模型与钢筋混凝土损伤加固梁端试件抗剪承载力计算模型,且对该计算方法进行了试验数据验证,为实际工程加固设计提供理论基础。
[Abstract]:The current Code for aseismic Design of buildings (GB50011-2010) and the old edition of the Code clearly stipulate the seismic fortification target of "minor earthquake is not bad, moderate earthquake can be repaired, large earthquake can not fall", and how to take reasonable and effective measures for "moderate earthquake can be repaired". The convenient repair and reinforcement technology is the key problem to be solved in the engineering. Reinforced concrete (Liang Zhu) is an important part of frame structure, which has a high damage risk under moderate level earthquake. The analysis of a large number of earthquake disasters shows that the seismic damage of building structure is usually concentrated at the end of the member. The study of its strengthening performance is not enough. In this paper, through experimental research, numerical simulation and theoretical analysis, the seismic behavior, mechanical characteristics and reinforcement measures of reinforced concrete columns and beam end specimens are studied. It provides the experimental and theoretical basis for the revision of the code for seismic design of buildings and the code for strengthening concrete structures in China. The main work and results include the design and manufacture of 6 reinforced concrete column specimens and 6 reinforced concrete beam end specimens. Two column specimens and two beam end specimens were loaded to failure at one time, and the test data were collected as a contrast specimen. Other specimens are strengthened after damage. The first step is to carry out low-cycle reciprocating damage test to the original specimen, the second step is to strengthen the damaged specimen with carbon fiber and steel plate, and then to carry on the low-cycle reciprocating test to the strengthened specimen. The variation parameters of column specimen are axial compression ratio and reinforcement mode, and the variation parameters of beam end specimen are longitudinal reinforcement ratio and reinforcement mode. The hysteretic property, skeleton curve, energy dissipation and ductility of the specimen are studied and analyzed. Stiffness degradation and failure patterns and other seismic performance. The test results show that the strengthened column specimens with low axial compression ratio consume more energy than those with large axial compression ratio, and the damaged beam end specimens strengthened with carbon fiber sheets can effectively restrain the plastic hinge extension and concrete shedding and breaking. It is difficult to determine the numerical model parameters of the damaged specimens, such as better bearing capacity, energy dissipation capacity and ductility. In this paper, the equivalent section stiffness method based on the section stiffness degradation coefficient and the section bearing capacity equivalent strength method based on the concrete strength damage coefficient are proposed. It is used to determine the key parameters of the numerical simulation of the specimens. The numerical modeling and analysis of the specimens strengthened in different ways are carried out by using the ANSYS finite element program. The results show that the numerical analysis results are in good agreement with the experimental results. Furthermore, the rationality and credibility of the model and the key parameters are verified. The results show that the bearing capacity of the strengthened column specimen and the beam end specimen has been improved to some extent. In this paper, the calculation model of shear bearing capacity of inclined section of reinforced concrete damage strengthened column and the shear bearing capacity of reinforced concrete damage strengthened beam end are established, and the experimental data are verified. It provides a theoretical basis for the reinforcement design of practical engineering.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU311.3;TU375

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