少钢支撑RC框架结构抗震性能研究

发布时间：2018-04-02 04:07

本文选题：钢筋混凝土框架结构　切入点：钢支撑　出处：《清华大学》2015年硕士论文

【摘要】：震害表明RC框架结构存在抗震防线单一、缺乏足够冗余度的问题。在RC框架结构中设置少量钢支撑,可以使结构具有多重抗震防线,提高其安全储备和抗震防倒塌能力。我国现行规范对含少量剪力墙的框架结构已经有了明确定义和相应的设计方法,而对于含有少量支撑的框架结构没有定义。本文重点研究了少钢支撑RC框架结构的定义方法和抗震防倒塌能力,在理论分析和试验的基础上总结了其设计方法,主要研究工作和成果如下:(1)有限元模型标定。基于Opensees平台建立有限元模型,与公开发表的试验进行对比验证,结果表明选取的有限元模型能够较好地模拟RC框架结构和钢支撑RC框架结构的弹塑性性能。(2)少钢支撑RC框架结构定义的提出。以8度(0.20g)设防烈度区一个典型RC框架结构及三个带不同钢支撑的RC框架结构为例,基于弹性分析和弹塑性Pushover分析,借鉴含有少量剪力墙的框架结构的定义方法,提出了以底部框架倾覆力矩分担率与抗侧刚度增量为控制指标的少钢支撑RC框架结构的定义。(3)少钢支撑RC框架结构抗震防倒塌能力评估。通过基于IDA的结构抗倒塌易损性分析,验证了各个设防烈度区的少钢支撑RC框架结构相比纯框架结构的抗倒塌能力提高,在超罕遇地震下有足够的抗震防倒塌能力。(4)钢支撑性能设计目标及抗震性能试验研究。以大震不断裂为目标,分别对普通钢支撑和屈曲约束支撑提出了性能设计要求。通过试验研究分析了截面形状、宽厚比以及内填混凝土对普通无缝钢管支撑屈曲模式、断裂延性的影响,并对普通无缝钢管支撑的设计方法提出了建议。提出了一种后装套管式新型屈曲约束支撑及其构造方法,相较常规构造方式可以提高屈曲约束支撑的工作段长度,增加其变形能力,且可用于既有普通钢管支撑的原位加固改造,通过试验研究验证了该构造方式的可行性。(5)少钢支撑RC框架结构的设计方法总结。以提高结构抗倒塌能力,保证在超罕遇地震水平下不倒塌为目标,结合理论分析和试验研究的结果,建议了少钢支撑RC框架结构的框架梁、柱、支撑构件设计方法。
[Abstract]:The earthquake damage indicates that the RC frame structure has the problem of single seismic defense line and lack of sufficient redundancy. A small amount of steel braces in RC frame structure can make the structure have multiple seismic defense lines. The current code of our country has clearly defined the frame structure with a small amount of shear wall and the corresponding design method. However, there is no definition of frame structure with a small amount of braces. In this paper, the definition method and anti-collapse ability of RC frame structure with little steel braces are studied, and the design methods are summarized on the basis of theoretical analysis and test. The main research work and results are as follows: 1) finite element model calibration. The finite element model based on Opensees platform is established and compared with the published experiments. The results show that the selected finite element model can well simulate the elastic-plastic properties of RC frame structure and steel braced RC frame structure. Frame structure and three RC frame structures with different steel braces for example, Based on elastic analysis and elastic-plastic Pushover analysis, the definition method of frame structure with a small amount of shear walls is used for reference. The definition of small steel braced RC frame structure with the ratio of overturning torque and the increment of lateral stiffness as the control index is proposed. The evaluation of seismic collapse resistance of RC frame structure with less steel braces is presented. The vulnerability analysis of the structure against collapse based on IDA is carried out. It is verified that the anti-collapse ability of the RC frame structure with less steel braced in each fortification intensity zone is higher than that of the pure frame structure. Experimental study on the design objective and seismic behavior of steel braces with sufficient seismic collapse resistance capability under super rare earthquakes. The performance design requirements of common steel braces and buckling restrained braces are put forward, respectively. The effects of section shape, width to thickness ratio and inner filled concrete on the buckling mode and fracture ductility of ordinary seamless steel pipe braces are analyzed through experiments. The design method of ordinary seamless steel tube brace is proposed, and a new buckling restrained bracing and its construction method are put forward, which can increase the working length of buckling restrained bracing compared with conventional structural method. It can be used in the in-situ reinforcement and reconstruction of existing steel tube braces. The feasibility of the structure is verified by experiments. The design methods of the RC frame structure with less steel braces are summarized in order to improve the collapse resistance of the structure. According to the results of theoretical analysis and experimental study, the design method of frame beam, column and bracing members of RC frame structure with less steel braces is suggested.
【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU375.4;TU352.11

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