基于弹塑性分析的RC框架结构抗震性能评估

发布时间：2018-06-30 17:00

本文选题：框架结构 + Pushover分析　；参考：《郑州大学》2014年硕士论文

【摘要】：随着我国社会生产力的快速发展和国民经济水平的不断提高,人们的防震减灾意识逐渐增强,国家标准对建筑抗震设防的要求也越来越高。因此,对既有建筑结构进行抗震性能分析与评估,了解其性能现状,并提出合适的加固改进方案,具有重要的现实针对性。本文以郑州市上街区某小学综合办公楼5层钢筋混凝土框架结构实际工程为背景,采用有限元软件SAP2000对该结构进行了静力弹塑性分析和动力非线性时程分析,通过计算分析,了解了该结构在不同地震动强度作用下的抗震性能水准。本文主要工作内容和结论如下：(1)按照原设计参数建立了5层钢筋混凝土框架结构的有限元模型,并与原设计计算的结构反力及自振周期进行了对比,验证了有限元模型的可靠性。(2)采用静力弹塑性分析方法(Pushover方法)研究了结构在不同地震动强度下的抗震性能水平,研究过程中同时采用了均匀分布侧向力加载模式和第一振型比例型加载模式。研究表明：这两种加载模式Pushover分析结果基本一致,原设计结构能够满足抗震规范规定的“小震不坏”、“中震可修”、“大震不倒”的最低性能要求。不同之处是,均匀分布侧向力加载模式低估了结构的层间位移角,而第一振型比例型加载模式则低估了结构的楼层剪力。因此,在进行类似中低层框架结构抗震性能评估时,需要将两种加载模式配合使用。(3)采用动力弹塑性时程分析方法研究了结构在不同地震动强度下的抗震性能水平。结果表明：原设计结构能够满足抗震规范规定的“小震不坏”和“大震不倒”的性能要求。这与Pushover分析结论是一致的。(4)对Pushover分析结果和动力非线性时程分析进行比较和总结,发现原设计结构破坏基本上呈“梁铰机制”,满足规范关于“强柱弱梁”的设计要求,说明原设计总体上是比较合理的。但是从分析得到的结构各层层间位移角以及各层梁柱塑性铰发展情况来看,结构第3层与4层交接处抗侧刚度突变,属于结构中相对薄弱部位,在构造上应予加强。
[Abstract]:With the rapid development of social productivity and the continuous improvement of national economic level, people's awareness of earthquake prevention and disaster reduction is gradually strengthened, and the requirements of national standards for earthquake resistance are becoming higher and higher. Therefore, it has important practical pertinence to analyze and evaluate the seismic performance of existing building structures, to understand the present situation of their performance, and to put forward appropriate reinforcement and improvement schemes. In this paper, based on the practical engineering of a 5 story reinforced concrete frame structure in a comprehensive office building of a primary school in Shangjie District of Zhengzhou City, the static elastoplastic analysis and dynamic nonlinear time history analysis of the structure are carried out by using the finite element software SAP2000, and the calculation and analysis are carried out. The seismic performance level of the structure under different ground motion intensity is studied. The main contents and conclusions of this paper are as follows: (1) according to the original design parameters, the finite element model of the five-story reinforced concrete frame structure is established and compared with the original design calculation of the reaction force and the natural vibration period. The reliability of the finite element model is verified. (2) the static elastic-plastic analysis (pushover method) is used to study the seismic performance of the structure under different ground motion intensity. In the course of the study, both the uniform distributed lateral force loading mode and the first mode proportional loading mode are adopted. The results show that the results of pushover analysis of the two loading modes are basically consistent, and the original design structure can meet the minimum performance requirements of "small earthquake not bad", "medium earthquake repairable" and "strong earthquake not collapsing" as stipulated in the seismic code. The difference is that the uniformly distributed lateral load mode underestimates the interstory displacement angle of the structure while the first mode of proportional loading mode underestimates the floor shear force of the structure. Therefore, it is necessary to combine the two loading modes to evaluate the seismic performance of similar middle and low story frame structures. (3) the dynamic elastoplastic time-history analysis method is used to study the seismic performance of structures under different ground motion intensity. The results show that the original design structure can meet the performance requirements of "small earthquake is not bad" and "large earthquake does not fail" as stipulated in the seismic code. This is consistent with the conclusion of pushover analysis. (4) the results of pushover analysis and dynamic nonlinear time-history analysis are compared and summarized. It is found that the failure of the original design structure is basically "beam hinge mechanism", which meets the design requirements of "strong column and weak beam" in the code. It shows that the original design is reasonable on the whole. But from the analysis of the displacement angle between each layer of the structure and the development of the Liang Zhu plastic hinge of each layer, it can be seen that the lateral stiffness at the junction of the third and fourth floors of the structure is relatively weak and should be strengthened in structure.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU352.11;TU375.4

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