圆钢管混凝土柱轴心受压承载力计算

Bearing capacity of circular concrete-filled steel tube columns under axial compression

利用353根钢管混凝土柱轴心受压试验结果,以混凝土强度、钢管强度和钢管径厚比为参数,分析《钢管混凝土结构技术规程》（CECS28：2012）中圆钢管混凝土柱轴心受压承载力计算方法的合理性.结果表明：CECS28：2012可以合理预测圆钢管混凝土短柱的轴心受压承载力,但对长柱的轴心受压承载力计算值过于保守且离散较大.在本研究参数取值范围内,提高混凝土强度和增大径厚比对CECS28：2012轴心受压承载力计算值准确性的影响不明显.随着钢管强度增大,圆钢管混凝土柱轴心受压承载力计算值与试验值的比值呈下降的趋势.基于CECS28：2012钢管混凝土短柱轴心受压承载力计算方法,提出适用于长细比为4~38.5的钢管混凝土长柱的轴心受压承载力折减系数计算公式,可为工程应用和规范修订提供参考.

A wide range of experimental data of 353 concrete-filled steel tabe（CFST） columns is used to evaluate the applicability of Technical specification for concrete-filled steel tubular structures CECS 28：2012 in calculating the bearing capacity of circular CFST columns.The effects of concrete strength,steel strength and diameter-to-thickness ratio on the accuracy of prediction according to CECS 28：2012 are discussed.The comparison results show that the design method in CECS 28：2012 can be used to predict short CFST columns accurately; but underestimates the bearing capacity of long CFST columns with large scatter.The concrete strength and the diameter to thickness ratio have slight influence on the accuracy of the design method.With the increasing of the steel strength,the ratios of the test results and prediction show a decreasing trend.On the basis of the design model in CECS 28：2012,a revised equation for slenderness reduction factor is given.