FRC框架结构基于等效单自由度模型的抗地震倒塌能力评估  

EVALUATION OF SEISMIC COLLAPSE CAPACITY OF FRC FRAME STRUCTURES BASED ON THE METHODOLOGY OF EQUIVALENT SDOF SYSTEMS

作　　者：黄超[1] 梁兴文[1] 党争 邢朋涛[1] 

机构地区：[1]西安建筑科技大学土木工程学院,陕西西安710055

出　　处：《工程力学》2016年第2期127-135,共9页Engineering Mechanics

基　　金：国家自然科学基金项目(51278402;51078305)

摘　　要：为了快速评估建筑结构的抗地震倒塌能力,该文基于Adam等提出的等效单自由度模型,首先用Pushover分析方法对纤维增强混凝土(FRC)结构进行静力弹塑性分析,获得其基底剪力-顶点位移曲线,据此确定其力-变形关系;然后根据力-变形关系以及侧向位移形状函数,确定相应的等效单自由度模型的相关参数;按等效单自由度模型计算结构的抗地震倒塌能力。分别对某8层钢筋混凝土框架结构和FRC框架结构进行分析。结果表明:用与多自由度结构相应的等效单自由度模型评估FRC框架结构的整体抗地震倒塌能力是可行和偏于保守的;采用抛物线加载模式比倒三角加载模式得到更接近由IDA分析所得的结构抗地震倒塌能力中位值;在其他条件相同时,FRC框架结构比普通混凝土框架结构具有更高的抗地震倒塌能力。In order to assess the seismic collapse capacity of building structures rapidly, an evaluation procedure is presented in the paper, which is based on the methodology of the equivalent single-degree- of-freedom（SDOF） model proposed by Adam. Firstly, static nonlinear analysis was conducted on a Fiber Reinforced Concrete（FRC） structure（the multi-degree-of-freedom（MDOF） system） by means of Pushover method; thereby a base shear-roof displacement curve was obtained. On the basis of this base shear-roof displacement profile, the relationship between the force and the lateral displacement of the structure was derived. According to this relationship and the function of lateral displacement of the MDOF system, the relevant parameters of the equivalent SDOF model were determined. The seismic collapse capacity of the equivalent SDOF model was then assessed, and the result was translated from the equivalent SDOF domain into the domain of the MDOF system, and then was compared with the median collapse capacity of the MDOF system based on the IDA method. An 8-story framed structure of normal concrete and an 8-story fiber reinforced concrete framed structure were analyzed respectively. The results show that it is feasible and conservative to use the equivalent SDOF model to assess the overall seismic collapse capacity of a MDOF system. The results using the lateral parabolic distributing load mode are more close to the median collapse capacities than those using the lateral inverted triangle distributing load mode, and the results of using the displacement shape vector corresponding to the peak point of load on the Pushover curve of the MDOF system are reliable. When other conditions are identical, the seismic collapse capacity of the frame with fiber reinforced concrete is higher than that of the frame with common concrete.

关 键 词：纤维增强混凝土 等效单自由度模型 抗地震倒塌能力 PUSHOVER分析 增量动力分析 

分 类 号：TU375.4[建筑科学—结构工程]