RC框架结构基于一致倒塌风险的抗震设计方法研究

发布时间：2018-05-15 15:15

本文选题：钢筋混凝土框架结构 + 逐步动力增量时程分析　；参考：《清华大学》2015年博士论文

【摘要】：本文以钢筋混凝土框架结构为研究对象,以结构在设计年限内的一致倒塌风险为研究目标,对RC框架的抗地震倒塌安全性能进行了系统的研究。主要研究内容如下:(1)采用基于IDA的倒塌易损性分析方法,定量评价了按我国现行建筑抗震设计方法设计的40个RC框架结构的抗地震倒塌能力。我国RC框架结构的抗倒塌安全储备系数CMR主要分布在2.0与3.5之间,地震动随机性引起抗地震倒塌能力的不确定性?RTR主要分布在0.40与0.55之间。(2)通过分析40个RC框架结构在44条地震动作用下的倒塌模式,发现框架柱在地震作用下丧失竖向承载力,继而导致上部结构在重力作用下发生竖向连续倒塌破坏,是框架结构在地震作用下最主要的倒塌模式。多层RC框架结构的地震倒塌破坏主要始于底部楼层,结构的一阶地震响应对多层RC框架的地震倒塌破坏起控制作用。(3)论述了结构抗地震倒塌能力的不确定性来源,应用中心点法定量估计了结构模型参数不确定性对结构抗倒塌能力的影响。(4)全面考虑结构所在场地的地震危险性,以结构在设计年限内的地震倒塌风险作为结构抗倒塌安全性能的度量,并给出了地震倒塌风险的定义和计算方法,在此基础上介绍了“一致倒塌风险”的抗震设计目标。结合我国第五代抗震设防区划,以P(collapse|Sa(T1)罕遇地震)10%和Pc,50年1.0%分别作为“大震不倒”和“一致倒塌风险”的定量目标,给出结构抗地震倒塌能力的目标。(5)利用基于IDA的倒塌易损性方法定量评价了SDOF结构的抗地震倒塌能力,并提出了结构抗地震倒塌谱。采用抗地震倒塌能力谱,系统研究了结构特性和地震动特性对SDOF体系抗地震倒塌能力的影响。(6)提出了基于SDOF结构的倒塌易损性简化预测方法,并给出了分析流程。通过40个多层RC框架的分析表明,本文建议的基于等效SDOF结构的倒塌易损性预测方法能够对多层规则RC框架的抗地震倒塌能力作出保守估计。
[Abstract]:Taking the reinforced concrete frame structure as the research object and taking the consistent collapse risk of the structure within the design years as the research goal, the safety performance of the RC frame against earthquake collapse is studied systematically in this paper. The main contents of this paper are as follows: (1) the collapse vulnerability analysis method based on IDA is used to quantitatively evaluate the earthquake collapse resistance of 40 RC frame structures designed according to the current seismic design method of buildings in China. The anti-collapse safety reserve coefficient (CMR) of RC frame structures in China is mainly distributed between 2.0 and 3.5. The uncertainty of earthquake collapse resistance caused by random ground motion (RTR) is mainly distributed between 0.40 and 0.55. By analyzing the collapse modes of 40 RC frame structures under the action of 44 ground motions, it is found that the vertical bearing capacity of frame columns is lost under earthquake action. The vertical continuous collapse and failure of the superstructure under the action of gravity is the main collapse mode of the frame structure under earthquake. The earthquake collapse failure of multi-story RC frame structure mainly begins at the bottom floor. The first-order seismic response of the structure controls the earthquake collapse damage of the multi-story RC frame. The influence of structural model parameter uncertainty on the collapse resistance of the structure is estimated quantitatively by using the center point method. (4) the seismic risk of the site of the structure is considered comprehensively. Taking the seismic collapse risk of the structure in the design life as the measure of the structural anti-collapse safety performance, the definition and calculation method of the seismic collapse risk are given, and the seismic design goal of "consistent collapse risk" is introduced. In combination with the fifth generation seismic fortification regionalization in China, 10% and 1.0% rare earthquakes are regarded as the quantitative targets of "strong earthquakes do not fail" and "consistent collapse risk" respectively in 50 years. The objective of anti-collapse ability of structures is given. (5) the seismic collapse resistance of SDOF structures is quantitatively evaluated by using the method of collapse vulnerability based on IDA, and the seismic collapse spectrum of structures is proposed. The influence of structural characteristics and ground motion characteristics on the seismic collapse resistance of SDOF system is systematically studied by using the seismic collapse resistance spectrum. A simplified prediction method of collapse vulnerability based on SDOF structure is proposed, and the analysis flow is given. The analysis of 40 multi-story RC frames shows that the proposed collapse vulnerability prediction method based on equivalent SDOF structure can conservatively estimate the seismic collapse resistance of multi-story regular RC frames.
【学位授予单位】：清华大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TU375.4;TU352.11

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