研究目的:为了改善站台雨棚和城市轨道等单排柱结构在列柱平面外的抗倒塌能力,提出由内圆柱和外圆环柱组成的混凝土核心分离组合柱,根据内圆柱和外圆环柱之间的连接状况分为无连接键和带连接键两类柱,通过2个大尺度试件的低周反复加载试验和多参数有限元分析,对比研究两类新型柱的刚度退化、承载力、延性和耗能等性能,得到内、外柱直径比和纵筋面积比等优化设计参数。
研究结论:(1)两类核心分离组合柱承载力、耗能量及弹性刚度均比同配筋量实心圆柱略低,但是当柱底区域混凝土破碎时,新型柱内柱混凝土损伤较轻,纵筋屈服明显迟于外柱,能承担起第二道抗震防线的作用;(2)带连接键柱中大部分混凝土连接键能进入塑性受力状态,初期刚度比无混凝土连接键柱大,但耗能能力稍差;(3)当内圆和外圆环柱半径比为0.4、配筋面积比为1:2~1:3时,两类混凝土核心分离组合柱能获得较优抗震性能;(4)本文相关成果可为铁路站台雨棚等单柱悬臂类结构中柱的设计提供参考。

Research purposes:For the purpose of improving seismic behaviors of the cantilever columns, which are usually used in single-row column structures such as platform canopy and urban metro, the paper proposed a concrete core separation column composed of an inner column and an outer ring column, and put forward two types of connection columns with connectors and without connectors between the inner column and the outer ring column. We conducted the low-cycle reversed loading test of two large scale dimension specimens and numerical analysis with multi-parameters. The stiffness degradation, bearing capacity, ductility and energy dissipation of two columns were investigated, and the optimal design parameters such as the diameter ratio of inner and outer columns and the area ratio of longitudinal reinforcement were obtained.
Research conclusions:(1) The bearing capacity, energy consumption and elastic stiffness of the two core-separation composite columns are slightly lower than those of solid columns with the same reinforcement. However, when the concrete at the bottom of the column is broken, the damage of the inner column is less, and the yield of longitudinal reinforcement is significantly later than that of the outer column. The inner column can serves as the second seismic line of defense effectively. (2) Most of the concrete connectors in the column with connectors are in the plastic stress state and the initial stiffness is larger than that of the column without concrete connectors, but the energy dissipation capacity is slightly poor. (3) When the radius ratio of inner and outer circular columns is 0.4 and the reinforcement area ratio is 1 ∶2~1 ∶3, the two types of concrete core separation composite columns have better seismic behavior. (4) The relevant results can provide reference for the design of single column cantilever structure such as platform canopy.