偏心钢支撑-钢筋混凝土框架的侧移和地震反应

SEISMIC RESPONSE AND STORY-DRIFT OF REINFORCED CONCRETE FRAME WITH ECCENTRIC STEEL BRACE

通过对偏心支撑钢筋混凝土框架试验结果的分析以及性能设计和抗震设计位移控制的比较,对其抗震设计中的变形和性能进行研究。为满足性能设计和三水准抗震设计要求,偏心支撑框架结构的侧移限值应比纯框架结构更严格,而且使得支撑的受压屈曲控制在第一水准位移后,将有利于抗震性能的改善。由于偏心钢支撑的作用,偏心支撑框架结构中柱的剪力明显减小,侧向刚度增大,从而有效地避免了框架结构在地震中柱的剪切破坏和过大的侧移。偏心支撑框架结构的地震反应如最大侧移、最大速度、最大加速度明显降低,结果表明,K型支撑是理想的抗震布置方式。

Depending on the experiment results analysis of the reinforced concrete frame eccentrically braced with steel （EBF structure） and drift limit comparison of performance-based design and three-stage seismic design, the deflection and behavior of EBF structure under seismic motion is discussed. From the point of three-stage principle of seismic design and performance-based design, the story-drift limit of EBF structure should be more strict than the pure frame. Because of the action of steel brace, the shear force of column in EBF structure is reduced and lateral stiffness of EBF structure is increased. The rupture of column and larger lateral deformation are avoided. It is also found that maximum deformation, acceleration, velocity and column shear of the EBF structure are obviously decreased comparing with the pure frame. The K-type brace is advantageous for the earthquake resistance.