复合箍对钢筋混凝土柱延性的改善

本文通过十四个配有复合箍的钢筋混凝土柱,在周期反复荷载下的抗震性能试验,研究了相同配箍率下,配箍形式对柱延性的影响。文中通过与普通方箍的对比,给出了反映复合箍约束效果的含箍特征值λ_k的修正系数α,并以αλ_k和混凝土名义压区高度系数ξ为参数,给出了计算柱延性比的经验公式。 文中还研究了周期反复荷载下曲率沿杆长的分布以及塑性铰区长度的变化规律,给出了计算塑性区长度的经验公式。

Improvement of Ductility of Reinforced Concrete Columns with Different Types of Stirrups

From the test results of 14 reinforced concrete columns with different types of stirrups under cyclic reversed loading, the effects of the stirrup type on the ductility of reinforced concrete column is discussed. Through the comparison of these types of stirrups with ordinary stirrups, a modification factor α of the characteristic value of stirrup ratio λk, which shows the confinement effect of different stirrups,is suggested. In order to calcu-Jate the ductility of such columns, an empirical formula with variables αλk and axial load ratio is presented. Both the curvature distribution along the member and the length of plastic hinge under cyclic reverse loading are studied, An empirical formula for computing the length of plastic hinge are given as well.