钢筋混凝土框架结构地震倒塌破坏研究

发布时间：2018-01-04 23:21

本文关键词：钢筋混凝土框架结构地震倒塌破坏研究　出处：《长安大学》2014年博士论文　论文类型：学位论文

【摘要】：任何情况下人的生命安全都是第一位的。强震作用下建筑物的倒塌造成的人员伤亡将引发一系列较财产损失更严重、更复杂的社会问题和经济问题。近年来国内外的数次震害表明即使严格执行抗震设计的建筑物也可能发生不同程度的倒塌破坏，大震不倒抗震设防目标未充分实现的根本原因在于未对结构倒塌破坏机理进行深入研究，缺乏准确的倒塌破坏临界状态定义和合理的倒塌破坏准则。本文重点研究了钢筋混凝土框架结构的倒塌破坏特点和破坏机理，建立了结构倒塌破坏分析模型、临界状态、破坏准则，主要涉及以下工作：深入分析总结了结构倒塌破坏研究方法，已有倒塌破坏准则本质上是构件设计的延伸，融入结构思想的倒塌研究考虑了构件、子结构、结构破坏的不确定性。薄弱区域的塑性变形集中是倒塌发生的根本原因，框架结构塑性变形集中区域就是柱铰大量充分发育的区域，此时结构内力重分布能力逐步下降，形成柱铰破坏机制。创造性的提出了结构域倒塌破坏分析模型和塑性铰密度倒塌破坏准则，在构件、子结构、整体结构三个层面上对倒塌研究进行了思考和探索，建立了可行的倒塌研究分析思路和方法。分析了结构倒塌破坏特性并提出了结构倒塌破坏分析模型，定义倒塌临界状态为地震作用下发生不同程度破坏后结构的极限性能，以倒塌区间代替单一倒塌临界值。根据同一层内受损构件的位置、破坏程度和数量等指标，将引起层倒塌的、破坏程度相近的同类型构件组合定义为倒塌关键区域，建立了域倒塌破坏分析模型。域失效是倒塌破坏发生的根本原因，真实反映了结构整体性能的退化规律和特点，适用于不同类型的倒塌研究。对框架结构的倒塌破坏机制和内力重分布特性进行深入分析，建议了基于柱铰的倒塌破坏准则。选取柱端塑性铰发育为倒塌分析变量，根据塑性铰发育程度、出现位置和数量等参数定义了塑性铰密度倒塌破坏准则。塑性铰密度破坏准则考虑了塑性铰发育与结构整体性能退化之间的相互关系。从构件损伤、子结构破坏和结构倒塌破坏三个层面上对倒塌破坏机理进行了解释和说明。薄弱层内一定量的柱铰充分发育后，结构的内力重分布能力丧失，子结构转化为可变机构，标志着倒塌的开始。试验研究和有限元分析表明域模型和塑性铰密度破坏准则较准确的解释和定义了结构倒塌临界状态、揭示了倒塌破坏机理。结构倒塌是由一定量的框架柱塑性变形集中引起的，柱端塑性变形是倒塌破坏研究的关键内容，对框架柱的损伤和塑性变形程度量化进行了研究：考虑滞回耗能与构件损伤的相互关系提出了有效耗能理论，建立了考虑延性和有效耗能比例的改进双参数破坏准则；研究了柱的截面破坏特性，在理论分析基础上通过数据回归得出了框架柱的极限曲率计算公式，建立了塑性铰发育量化方法。根据三榀平面框架的拟静力试验，，建立了OpenSees的纤维单元模型，进行了框架结构的反复加载试验验证，完成了基于塑性铰密度破坏准则的平面框架结构倒塌计算分析，选取倒塌破坏区间(0.6,1.0)能够准确的定义倒塌破坏极限，倒塌破坏指数较好的反映了结构的整体性能退化规律。选取114条地震波进行了框架结构的时程分析，根据倒塌破坏指数大小从中选取了10条地震动作为后续参数分析的地震动数据库。完成了不同层数、层高、跨度、轴压比的倒塌破坏计算分析，计算表明随着层数、层高、跨度、轴压比的增加倒塌破坏总体呈现加剧的趋势，基于域模型的塑性铰密度准则能够较好的定义结构倒塌破坏，地震动随机性对结构倒塌破坏的影响不容忽视。
[Abstract]:Any human life safety is the first one. The building collapsed under strong earthquake caused casualties will cause a series of property loss is more serious, more complex social and economic problems. In recent years, several earthquake damage at home and abroad show even if the strict implementation of seismic design of buildings may collapse damage the fundamental reason that earthquake does not fall without the full realization of the goal of seismic fortification is not in-depth study of the structure collapse mechanism, the lack of accurate and reasonable definition of the critical state of collapse collapse criterion. This paper focuses on the collapse of reinforced concrete frame structure failure characteristics and failure mechanism, establish collapse analysis model, structure the critical state, failure criterion, mainly involves the following work:
It analyzes the existing research methods of structure collapse, collapse criterion is essentially the extension component design, the collapse of research into the structures of thought into components, sub structure, structural damage of uncertainty. The concentration of plastic deformation of weak area collapse cause of the frame structure of plastic deformation area is the column a hinge fully developed region, the structure internal force redistribution ability decreased gradually, destroy the column hinge mechanism. Put forward the innovative collapse analysis model and plastic hinge density collapse criterion, the components, sub domain structure, three aspects of the overall structure of the thinking and exploration of the collapse of a. Study on the collapse of feasible analysis ideas and methods.
Analysis of the collapse characteristics and puts forward the analysis model of structure collapse, collapse the definition of critical state under the action of earthquake occurrence limit performance of the structure after the destruction of different degree, to collapse interval instead of single collapse critical value. According to the same layer within the damaged member position, extent of damage and the number of other indicators, will cause the collapse of the layer the same type of failure, component composition close to the collapse degree definition of key areas, establish domain collapse analysis model. The failure domain is collapse cause, reflect the degradation rules and characteristics of the whole performance of the structure, suitable for different types of collapse.
The collapse of the frame structure and the mechanism of redistribution of internal force characteristics of in-depth analysis, suggestions of collapse column hinge failure criterion. Based on the selected column plastic hinge development for the collapse analysis of variables, according to the plastic hinge development degree, the parameter is defined by the position and number of plastic hinge density plastic hinge collapse criterion. The density criterion considered the relation between the degradation of plastic hinge structure development and overall performance. From the damage, collapse of three aspects of the interpretation and explanation of the collapse mechanism of structure damage and structure. A quantitative thin layer column hinge of the full development, internal force redistribution ability loss sub structure into variable mechanism, marked the collapse of the beginning. Experimental study and finite element analysis show that the domain model and the density of plastic hinge failure criterion more accurate explanation and definition of the structure collapse The mechanism of collapse is revealed.
Structural collapse is caused by a certain amount of plastic deformation of frame column, column plastic deformation is the key content of the collapse, the frame column damage and plastic deformation quantization are studied: consider the relationship between hysteretic energy dissipation and damage proposed effective energy dissipation theory, an improved double the parameters considered effective ductility and energy dissipation ratio criterion; on the cross section of the column failure characteristics, on the basis of theoretical analysis of data obtained through the regression formula of the ultimate curvature of frame column, a plastic hinge development of quantitative methods.
According to the pseudo static test of three frames, a fiber element model of OpenSees, the cyclic loading test of frame structure, completed the calculation and analysis of collapse of plane frame structure plastic hinge failure criterion based on density, selection of collapse interval (0.6,1.0) can accurately define the collapse limit, the collapse index is better the reflection of the degradation of the whole performance of the structure. 114 seismic waves were selected by the time history analysis of frame structure, according to the analysis parameters as subsequent collapse index size selected from the 10 earthquake ground motion database. The number, height, span, calculation and analysis of axial compression ratio of collapse damage the calculation shows that as the number, height, span, the axial compression ratio increases the overall collapse show increasing trend, based on the domain model of plastic hinge density criterion can be well defined The effect of the randomness of the ground motion on the collapse of the structure can not be ignored.

【学位授予单位】：长安大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU375.4;TU312.3

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