Study of evaluation of equivalent plasti chinge length of reinforced concrete columnsofreinforcedconcretecolumns

DOI：10.7511/dllgxb201706006

 作者 单位 仇建磊, 张艳青, 贡金鑫

等效塑性铰长度是确定压弯钢筋混凝土柱塑性转动能力和极限位移能力的重要指标.为准确计算等效塑性铰长度,首先通过截面分析推导得出塑性铰长度的影响参数,根据计算分析结果,建立考虑弯曲作用的等效塑性铰长度计算公式;收集PEER数据库30个弯曲破坏柱极限水平位移数据,在此基础上进一步提出考虑纵筋滑移影响的等效塑性铰长度计算公式;最后,采用所提公式与现有其他等效塑性铰长度计算公式,计算得出柱极限水平位移,并与试验数据进行对比.研究结果表明:压弯钢筋混凝土柱塑性铰长度主要与轴压比n、受拉纵筋配筋率ρ 有关,随着n 的增大和ρ 的减小,塑性铰长度不断减小;所提公式与试验数据吻合良好,可以用于压弯钢筋混凝土柱抗震设计分析.

The equivalent plastic hinge length is an important indicator of rotational capacity and deformation capacity of reinforced concrete column subject to compressive and bending forces. In order to accurately calculate the equivalent plastic hinge length, the influence parameters of plastic hinge length are derived by cross-section analysis, and then the calculation equation of equivalent plastic hinge length considering the influence of flexural action is established. Furthermore, the calculation equation of equivalent plastic hinge length considering the influence of slippage of reinforcing bars is proposed based on the ultimate displacement data of 30 flexural destroyed reinforced concrete columns collected from the database of PEER. Finally, the ultimate displacement results calculated by the proposed formula and other formulas are compared. It′s found that the plastic hinge length is mainly influenced by axial ratio n and tensile longitudinal reinforcement ratio ρ, it can decrease with the increase of n and the decrease of ρ. A good agreement between test results and calculated results by proposed formula is achieved and the proposed formula is suitable for seismic analysis of reinforced concrete columns subject to compressive and bending forces.