部分抗剪连接的型钢混凝土组合柱正截面承载力计算

在JGJ 138-2001《型钢混凝土组合结构技术规程》中，型钢混凝土柱的正截面承载力需根据平截面假定进行计算，但该规范并没有明确给出当平截面假定不满足时型钢混凝土柱的承载力计算方法。为此，提出抗剪连接系数的概念，用于描述型钢混凝土柱中型钢与混凝土之间的相对界面抗剪能力，综合平截面假定和叠加原理，得到在部分抗剪连接条件下普通型钢混凝土（SRC）柱和分散型钢混凝土（ISRC）柱的正截面承载力与抗剪连接系数之间的定量关系，进而提出SRC柱和ISRC柱的正截面承载力设计简化方法。计算结果表明：当轴压比相同时，SRC柱和ISRC柱的受弯承载力随其抗剪连接系数的增大而增大；轴压比越大，抗剪连接系数对组合柱的受弯承载力的影响越小；与SRC柱相比，抗剪连接系数对ISRC柱的受弯承载力影响更加显著。试验结果与计算结果的对比表明，采用所提出的方法可以较准确地计算ISRC柱的压弯承载力，计算结果具有一定的安全余度。

Capacity of steel-concrete composite columns with partial shearconnection under combined compression and bending

In the standard JGJ 138—2001 ‘Technical specification for steel reinforced concrete composite structures’, the flexural capacity of steel reinforced concrete (SRC) columns shall be calculated based on the plane section assumptions (PSAs), but fails to give a design philosophy for this kind of columns when the PSAs are not applicable. The concept of shear connection index was proposed in this paper to reflect the relative shear capacity on concrete-steel interfaces. A method was proposed to quantify the relationship between the shear connection index and the flexural capacity of SRC and ISRC columns with partial composition action by combining PSAs and superimposition principles.The calculation results confirm that: 1) the flexural capacity of SRC and ISRC columns increases with the shear connection index under constant axial compression ratio; 2) the influence of shear connection index decreases with the increase of the axial compression ratio; and 3) the influence of shear connection index is more significant for ISRC columns than SRC columns. By comparing the calculated results with test results, it is confirmed that the proposed method can predict the flexural capacity of ISRC columns with enough accuracy and redundancy.