平面不规则钢筋混凝土框架结构基于性能的抗震评估方法

Method of performance based seismic evaluation for irregular plane reinforced concrete frame structures

从现行规范对平面不规则结构的限制条件出发,推导扭转角与扭转位移比的关系式,结合钢筋混凝土框架结构在不同地震作用水平下的层间位移角限值,建立平面不规则结构的层间扭转角需求曲线;依靠现有有限元分析程序计算结构构件的扭转角和扭转角能力曲线,提出平面不规则钢筋混凝土框架结构基于性能的抗震评估方法——扭转角能力谱法。通过算例对扭转角能力谱法的使用方法和原理进行阐述,建立平面不规则结构的评估曲线,分析结构不同楼层各构件的扭转变形性能。结果表明,扭转角能力谱法既可以一目了然地判别出楼层与楼层之间的扭转变形关系,又可以准确地判别出同一楼层各抗侧力构件的扭转变形性能,从而全面的实现各构件基于性能的抗震评估。

Based on the provisions on irregular plane structures in the China technical specification for tall buildings, the relationship between inter-story torsion angle and torsion deformation ratio is derived. Considering the inter-story ratio limit values for performance levels under different earthquake hazard levels, a series of torsion angle demand curves are established. Using existing finite element analysis software, the structural torsion angle and capacity curves are obtained. A new method named torsion angle capacity spectrum method is put forward for performance based seismic evaluation of irregular plan frame structures, Examples are presented to explain the method principle and to demonstrate the applicability and utility of the proposed method. The evaluation curves are established and the torsional deformation is analyzed. It is concluded that the new method can identify the torsional displacement not only between stories but also among structure members within the same story.