八度区不等层高异形柱框架抗震性能研究

Seismic behavior of unequal height storey frame with specially shaped columns in eight intensity zone

目前关于八度区不等层高异形柱框架抗震性能的相关研究较少,而笔者按现行异形柱规程设计制作了一榀1/3缩尺不等层高异形柱框架并对其进行低周往复加载试验,研究分析了该类型结构的破坏特征、破坏机制、承载能力和变形能力、滞回曲线、刚度退化等抗震性能指标。研究表明,该类型框架破坏机制属于混合机制,在较高地震作用下,框架梁柱节点核心区具有足够的抗剪强度,整体抗震性能良好,但在加载后期,底层柱脚混凝土破坏较严重,降低了结构的承载能力,成为结构的薄弱部位,在设计中应予以重视。

Because the research in seismic behavior of unequal height story frame with specially shaped columns in eight intensity zone is less,a 1/3-scale RC frame of unequal height story with specially shaped columns was designed based on the Specification for Concrete Structure with Specially Shaped Columns,and it was tested under low frequency cyclic loading.The damage characteristic,failure mechanism,carrying capacity and deformation capacity,hysteresis curves,and stiffness degeneration of this frame were analyzed.It is shown that the failure mechanism of this frame is hybrid mechanism,the beam-column joints core of the frame has enough shear strength under high seismic condition,and the whole seismic behavior of this frame of unequal height story with specially shaped columns is generally good.But in the later loading,the concrete of column bottom in first floor is destroyed seriously,which reduces the carrying capacity of the structure,so the column bottom of the first floor is a weak part of the structure and should be paid more attention to in design.