圆钢管混凝土轴压长柱极限承载力的稳定系数法

Stability coefficient method for ultimate strength of long concrete-filled steel tubular columns under axial compression

为完善圆钢管混凝土轴压长柱极限承载力的计算理论,对比分析了中国国家标准GB50936—2014和CECS 28:2012中轴压短柱极限承载力的N0计算公式,并把GB 50936—2014中基于套箍系数的N0计算公式改写成统一的形式,提出了基于正则长细比的轴压长柱的稳定系数计算式,并通过36个试件的对比,对计算式的精度和适用范围进行了分析。研究表明,现行国标GB 50936—2014中基于套箍系数的N0计算公式更为精确,基于N0计算公式和本文的稳定系数,可以计算得到更为精确的轴压长柱的极限承载力。

The ultimate strength formula of short columns under axial compression, which were given by the current code GB 50936-2014 and the current specification CECS 28. 2012, were compared and analyzed to improve the theory of ultimate strength of long concrete-filled steel tubular columns under axial compression. The formula of the ultimate strength of short columns, basing on confinement coefficient which was given by GB 50936-2014, was rewritten as a unified form. A new stability coefficient was proposed for long concrete-filled steel tubular columns under axial compression. The accuracy of the proposed stability coefficient was validated by 36 specimens. The results show that the formula of short columns based on the confinement coefficient and the proposed stability coefficient can provide good prediction of ultimate strength for both short and long concrete-filled steel tubular columns under axial compression.