钢管混凝土叠合柱受力性能研究

Researches on behavior of steel tube-reinforced concrete columns

为研究钢管混凝土叠合柱受力性能,本文首先根据叠合柱截面上的应变发展对其管内外混凝土轴力重分布机理及截面塑性变形能力进行了分析,然后采用条带法编制MATLAB计算程序得到了钢管混凝土叠合柱弯矩-曲率及荷载-位移关系曲线。将理论计算值与试验结果进行对比,验证了条带法分析模型的有效性。在此基础上,分析了名义轴压比n、叠合比m、管外混凝土纵筋配筋率ρ、套箍系数θ、管外混凝土配箍特征值λ各主要参数对钢管混凝土叠合柱管内外混凝土部分轴力重分配关系及构件延性的影响,同时讨论了叠合比、配箍特征值等参数对轴力-水平荷载(n-p)曲线的影响。最后根据参数分析的结果,建议了在满足叠合柱延性需求(u△≥3)的基础上,叠合柱名义轴压比限值及相应的最小配箍特征值,为叠合柱的工程设计提供参考。

To study the behavior of steel tube-reinforced concrete columns, firstly by section analysis, this article illustrates the mechanism of axial force redistribution and section plastic deformation capacity, than the composite column moment-curvature and load-displacement curve is obtained by using the strip method with MATLAB. The results of theoretical analysis are in good agreement with the experimental ones, confirming the effectiveness of the strip method. On the basis, the factors such as nominal axial compression ratio, laminated ratio, longitudinal reinforcement ratio, confinement coefficient, stirrup characteristic values which affect axial force redistribution and ductility of composite column have been analyzed. Besides, the influence of some parameters such as confinement coefficient and stirrup characteristic value on the correlation curve of n-p are discussed. According to the results of parameters analysis, the limited values of nominal axial compression ratio and minimum stirrup characteristic values under ductility demand （u△≥ 3 ）is also suggested which can provide a reference for designing steel tube-reinforced concrete column.