钢筋混凝土框架结构抗地震倒塌能力评估的简化方法

发布时间：2018-06-07 03:56

本文选题：RC框架结构 + 增量动力分析　；参考：《西安建筑科技大学》2015年硕士论文

【摘要】：钢筋混凝土(RC)框架结构在我国目前的结构形式中占了相当大的比例,其抗地震倒塌能力是保障人民生命财产安全的重要指标。我国现存的大量钢筋混凝土框架结构原设计的依据标准过低,加上耐久性及损伤积累等因素使得结构的承载力有所降低。如何合理评估建筑结构的抗地震倒塌能力成为重要的前沿课题,迫切需要发展一套指标来定量评估建筑结构的抗地震倒塌能力,使得抗震能力不足的建筑结构能及早加固或拆除,在最大程度上保证结构“大震不倒”。考虑到抗倒塌分析一般需要进行动力弹塑性时程分析,耗时较长且建模过程繁琐,这对大量的既有建筑是不切实际的。因此,本文基于增量动力分析方法,提出一个简化的抗倒塌评估指标,仅通过简单的计算即可对结构的抗地震倒塌能力进行定量评估。主要研究工作和成果如下:(1)对按照我国现行抗震规范设计的设防烈度8度区的RC框架结构进行易损性分析,在预期的罕遇地震强度下对倒塌性能进行了定量评估。结果表明,按照我国现行抗震规范设计的RC框架结构,可以满足在预期的罕遇地震下结构的抗地震倒塌要求,发生倒塌的概率较小,对人身安全有较充分的保障。(2)分析比较了基于PERFORM-3D的纤维模型和塑性铰模型。结果表明,二者的结构响应基本相同,对结构的倒塌性能评估影响差异较小,考虑到建模的方便性和评估的可靠性,推荐采用纤维模型。(3)讨论了“强柱弱梁”对结构抗倒塌性能的影响,通过调整柱、梁抗弯承载力比c b?M/?M来考虑这种变化。结果表明,柱、梁抗弯承载力比对结构的抗倒塌性能影响显著,并确定了对应于基准建筑的最优比值。(4)讨论了“强剪弱弯”对结构抗倒塌性能的影响,通过调整箍筋间距及配置改变参数p uV/V来考虑这种变化。分析结果表明,p uV/V的变化对结构的抗倒塌性能也有一定的影响。(5)综合上述两个参数,分析其对结构抗倒塌性能影响的相关性。对其他8度区的建筑结构,可通过上述两个参数的简单计算,参考已有研究成果对其抗倒塌性能进行定量评估。
[Abstract]:Reinforced concrete (RC) frame structure accounts for a large proportion of the present structural forms in China, and its ability to resist earthquake collapse is an important index to ensure the safety of people's lives and property. A large number of existing reinforced concrete frame structures in our country have a low design standard, together with durability and damage accumulation factors, which make the bearing capacity of the structure reduced. How to reasonably evaluate the ability of building structures to resist earthquake collapse has become an important frontier issue. It is urgent to develop a set of indicators to quantitatively evaluate the ability of building structures to resist earthquake collapse. So that the structure with insufficient seismic capacity can be strengthened or dismantled as soon as possible to ensure that the structure will not collapse after a large earthquake. Considering that dynamic elastic-plastic time-history analysis is usually required for anti-collapse analysis, it takes a long time and the modeling process is cumbersome, which is impractical for a large number of existing buildings. Therefore, based on the incremental dynamic analysis method, this paper presents a simplified evaluation index of anti-collapse, which can be quantitatively evaluated by simple calculation. The main research work and results are as follows: (1) vulnerability analysis of RC frame structures designed according to the current seismic code of China is carried out, and the collapse performance is quantitatively evaluated under the expected earthquake intensity. The results show that the RC frame structure designed according to the current seismic code in China can meet the earthquake collapse requirements of the structure under the expected rare earthquake, and the probability of collapse is relatively small. The fiber model and plastic hinge model based on PERFORM-3D are analyzed and compared. The results show that the response of the two structures is basically the same, and the difference on the collapse performance of the structures is small. Considering the convenience of modeling and the reliability of evaluation, The influence of "strong column and weak beam" on the collapse resistance of the structure is discussed. This change is considered by adjusting the bending bearing capacity ratio c b?M/?M of the column. The results show that the flexural bearing capacity of columns and beams has a significant effect on the collapse resistance of the structure, and the optimum ratio corresponding to the reference building is determined. (4) the influence of "strong shear and weak bending" on the collapse resistance of the structure is discussed. This change is considered by adjusting the stirrups spacing and changing the configuration parameter p uV/V. The results show that the variation of uV/V has a certain influence on the collapse resistance of the structure. (5) synthesizing the above two parameters, and analyzing the correlation of the influence on the collapse resistance of the structure. Through the simple calculation of the above two parameters and referring to the existing research results, the anti-collapse performance of the other 8 degree building structures can be quantitatively evaluated.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU375.4;TU352.11

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