【作者】 梁炯丰；

【导师】 薛建阳；

【作者基本信息】 西安建筑科技大学 ， 防灾减灾工程及防护工程， 2013， 博士

【摘要】 在我国，火电厂主体结构常采用钢筋混凝土框排架结构，而随着电厂单机容量的不断增大，主厂房的高度和跨度随之增加，具有布置灵活、自重轻、强度高、施工快、抗震性能好等优点的钢结构，成为了中国大型火电厂主厂房的主要结构形式，尤其成为在抗震设防区建造大型火电厂的首选形式。课题组前期已经研究了大型火电厂钢结构异型节点受力性能，为了揭示大型火电厂钢结构主厂房框排架结构抗震性能，建立其相对应的设计方法，本文进行了系统研究。设计了1榀缩尺比为1/10三跨五层的钢框排架模型，通过对其进行拟动力试验，研究其在预估地震作用下的加速度反应、位移反应、滞回特性、刚度和耗能性能。研究结果表明：钢框排架结构延性相对较好，具有较强的塑性变形能力。模型结构在三种地震波(El Centro波、Taft波、兰州人工波)的多遇地震以及ElCentro波的罕遇地震作用下，层间位移角均满足我国现行规范要求。钢框排架结构体系可满足8度设防要求，具有良好抗震性能。在拟动力试验结束后，又对该榀钢框排架结构进行了拟静力试验，观测了框排架的破坏形态，得到了试件的荷载—位移滞回曲线、骨架曲线，分析了钢框排架的破坏机制、滞回性能、延性、耗能能力、刚度退化等力学性能。结果表明：钢框排架结构的破坏机制为先梁端后柱端出现塑性铰的混合破坏机制，滞回曲线较饱满，整体位移延性系数大于4.0，等效黏滞阻尼系数达到0.185。钢框排架结构体系总体上表现出良好的抗震能力，适合高烈度抗震设防区采用。模型结构的层间位移角在底层和第二层较大，为薄弱层;煤斗梁地震反应较强，设计时要特别注意。采用有限元软件Sap2000对平面钢框排架结构进行了时程分析，计算结果与试验结果符合较好。根据计算结果，对钢框排架结构的变形性能进行了分析，明确了大震作用下塑性铰的出现次序和发展规律，研究了错层对结构性能的影响和框架、排架之间的协同工作情况。采用有限元软件Midas/gen对钢框排架整体厂房进行了弹性时程分析、弹塑性时程分析、静力弹塑性分析，研究了主厂房的变形能力、薄弱部位、受力机理及其破坏机制。计算结果表明：钢框排架延性相对较好，具有较强的塑性变形能力和抗震能力。主厂房横向框排架和纵向框架—支撑结构存在较多的薄弱部位；煤斗梁刚度超强，要特别注意柱截面的选取，结构计算分析应采用考虑扭转效应的空间模型。参考国内外规范相关规定，将钢框排架结构的性能水平划分为正常使用、基本使用、生命安全和接近倒塌四个等级，并结合地震设防水准，给出了钢框排架结构的抗震性能目标。在钢框排架结构抗震性能试验研究的基础上，提出了钢框排架对应四个性能水平的层间位移角限值。给出了基于位移的设计方法在主厂房钢框排架结构设计中的设计步骤，并以一工程实例详细说明了钢框排架结构基于位移的设计过程。提出根据结构损伤期望对钢框排架结构进行抗震优化设计，并建立了钢框排架结构抗震优化设计的数学模型，给出了其优化设计步骤。基于ANSYS软件的二次开发平台，采用APDL语言编制了钢框排架结构抗震优化设计程序，并采取该程序对一工程实例进行抗震设计优化，验证了所采用的优化思路和方法的可行性。在试验研究和理论分析基础上，结合火电厂特点和多高层钢结构设计方法，提出了钢框排架主厂房的抗震设计建议，可为工程应用提供参考。更多还原

【Abstract】 In China, the reinforced concrete frame-bent structure often are used in the mainstructure of the thermal power plant, while the height and span of the main power houseincreased with the increasing of the power plant unit capacity, the steel structure withflexible layout, light weight, high strength,quickly construction, good seismicperformance advantages, has become the main structure of the main plant of largethermal power plants.In particular, it has become the preferred form of construction oflarge thermal power plants in the earthquake-proof.The mechanical behavior of irregularjoints of steel structure of large thermal power plants have been studied. Based on theprevious studies, the research on seismic performance and design method of steelframe-bent structures of large thermal power plant main buildings is systematicallyperformed in this dissertation.According to the experimental study on a1:10model of steel frame-bent structureunder pseudo-dynamic test.The seismic responses such as acceleration,displacement,varying stiffess,hysteretic property and energy consumption were analyzed. The resultsshow that the steel frame-bent structure has good ductility and strong plastic deformationcapacity. The maximum story drift angles of the model structure under intensity8frequent and rare earthquakes are all less than their limit values regulated by the presentseismic code. Steel frame-bent structures satisfied the demand of seismic design in8intensity zones,and has good seismic behaviors. After the pseudo-dynamic test, theexperimental study on the model of a three-bay and five-story steel frame-bent structuresunder low cyclic reversed loading was to do. The failure condition of frame-bent structures is observed. The load-displacement hysteretic loops and skeleton curve oftested model are obtained. The failure mechanism, hysteretic behavior, ductility, energydissipation capacity and stiffness degeneration were investigated. The results show thatthe failure mechanism of steel frame-bent structures is the first occurrence of beam-hingeand then column-hinge mechanism.The hysteretic loops are a plump.The average of theoverall ductility factors is greater4.The equivalent viscous dampings coefficient is0.185.The steel frame-bent structures exhibits excellent seismic behavior, and can beadopted in high seismic fortification zones. The inter-story displacement rotation isrelatively large on the bottom floor and the second floor, namely the weak floor. Andthere is larger earthquake action at the coal hopper beams, which must be paid attention indesign.The time history response analysis on flat steel frame bent structure were carried outby using SAP2000.The calculated results agree well with experimental results.According to the calculated results, the deformation performance are analyzed, the plastichinges in the order and law under strong earthquakes are got. The influence of structureproperties from split-level, coordination between the frame and bent work.The elastic time history response analysis method, dynamic elastic-plastic analysismethod, static pushover analysis method are used to study the deformation, weak parts,loading capacity and failure mechanisms of steel frame-bent structures of large thermalpower plant main buildings by using Midas/gen. The results show that the steelframe-bent structure has good ductility, strong plastic deformation capacity and seismicperformance. But the horizontal frame-bent and longitudinal frame-supporting structureshave much weak parts, and there is larger earthquake action at the coal hopper beams,which must be paid attention when designed.It should be used the space modelconsidering the effect of torsion on the structure to calculate and analysis.Refer to the domestic and foreign relevant norms，four performance levels are putforward for steel frame-bent structures, which are normal operation, basic operation, lifesafety and collapse prevention. The seismic levels and four performance levels arecombined to form the seismic performance target. Based on the results of seismicperformance tests on steel frame-bent structures, the maximum inter-story drift anglecorresponding to different performance levels are presented for the steel frame-bent structures. The displacement-based seismic design(DBSD) method was proposed to steelframe-bent structures. The procedure of the DBSD was given, and taking one steelframe-bent structure of main building as an example, the design process wasdemonstrated.The seismic optimal design of the steel frame-bent structures based on structuraldamage expectations was proposed. The seismic optimal design mathematical model ofthe steel frame-bent structures was set up and the optimized design steps were given.Theseismic optimal design program of the steel frame-bent structures was compiled by usingAPDL based on the secondary development platform in ANSYS. The feasibility ofoptimizing idea and method was verified by an engineering example.Based on experimental study and theoretical analysis, combined the characteristicsof thermal power plants and high-rise steel structure design method,the seismic designrecommendations of steel frame–bent structures of main buildings were proposed,whichcan provide a reference for engineering applications.更多还原