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钢-混凝土组合结构体系抗震性能研究与地震易损性分析
【作者】 刘阳冰；
【导师】 刘晶波；
【作者基本信息】 清华大学 ， 土木工程， 2009， 博士
【摘要】 钢-混凝土组合结构在我国得到迅速的发展和越来越广泛的应用,但目前国内外大部分组合结构还未经过强震检验,对结构抗震性能的研究亦不够充分。本文采用理论分析和数值模拟方法,对钢―混凝土组合结构的抗震性能和地震易损性等问题进行了研究。主要工作和取得的成果有:(1)在已有方钢管混凝土构件试验和理论研究的基础上,通过理论分析和大量的参数分析,提出了一种方钢管混凝土柱塑性屈服面快速确定方法。对现有方钢管混凝土柱和钢―混凝土组合梁的三折线弯矩-曲率关系曲线进行了修正,提出了适用于钢-混凝土组合梁和方钢管混凝土柱弹塑性分析的四折线弯矩-曲率本构曲线。(2)进行了钢―混凝土组合框架结构抗震性能分析,较为系统地对比了五种不同类型框架结构的受力、变形性能以及破坏状态。初步提出了实现组合梁-方钢管混凝土柱框架结构“强柱弱梁”的设计公式,为组合框架结构的设计提供参考。(3)给出了一种基于性能的结构地震易损性分析方法。定义了结构整体和楼层的四个极限破坏状态,提出了基于结构极限破坏状态确定结构抗震性能水平限值的方法。对两个不同类型的钢―混凝土组合框架结构进行了地震易损性分析,对结构的易损性能进行评估。讨论了地震需求变异性的影响,研究了基于全概率和半概率的结构地震易损性分析方法的差异和转化关系。(4)对组合框架―混凝土核心筒结构的抗震性能进行了弹塑性地震反应分析和参数影响分析。研究了框架伸臂梁连接方式,梁柱截面、核心筒厚度等参数对结构变形和受力性能的影响,探讨了组合框架―混凝土核心筒结构的地震破坏模式、分析了结构变形和外框架剪力随地震作用增大的变化规律,可为结构的设计提供参考。对比了Pushover方法和弹塑性时程方法计算结果的差别,讨论了Pushover方法的适用性。
【Abstract】 Steel-concrete composite structures have been developed rapidly and widely used in China. But most of steel-concrete composite structures of native and abroad have scarcely undergone a strong earthquake, and the research on the aseismic performance of this type of structure is not enough. Based on theoretical analysis and numerical simulation, aseismic performance and seismic fragility of steel-concrete composite structures are studied. The main achievements of this dissertation are as follows:(1) Based on experimental and theoretical research on concrete-filled square tubular (CFST) members, a method for quick determining the plastic interactive yield surface of CFST columns is developed through theoretical analysis and large number of parametric analyses. The trilinear moment-curvature curve of CFST columns and steel-concrete composite beams are amended and the 4 poly-line moment-curvature curve models are respectively suggested for elasto-plastic analysis of CFST columns and steel-concrete composite beams.(2) The seismic performance analysis of steel-concrete composite frame structures is performed. And the mechanical properties, deformation behaviors and damage states of the five different frame structures are compared systemically. Furthermore the design formula to make sure the strong column-weak beam mechanism of the composite beams - CFST columns frame are preliminarily put forward, which can offer some valuable references in design of composite frame structures.(3) A fragility analysis method of performance-based is given. And four ultimate damage states for the entire structure and interstory are defined. Based on the ultimate damage states, a method of solving the limited values of the four performance levels is put forward. Furthermore, seismic fragility analysis is carried out for two different steel-concrete composite frames to assess the seismic fragility of the two frames. The influence of seismic demand variation is discussed. And the difference and conversion between total probability and half probability method of seismic fragility analysis are studied.(4) Elasto-plastic seismic response and parameters influence analysis of composite frame-concrete core wall structures are studied. The effects of connection forms of frame outrigger beams and parameters such as sections of beams and columns, thickness of frame-core tube etc. on the deformation and mechanical behavior of structures are investigated. The seismic damage model and the variation law of deformation and frame shear force with the increasing of the earthquake action are probed into. The results given in this paper can be helpful to practical seismic design for composite frame-concrete core wall structures. At last, the results of pushover analysis and elastic-plastic time history analysis are compared. And the applicability of pushover analysis method is discussed.