异形截面多腔钢管混凝土柱轴压承载力计算方法研究

Bearing capacity calculation method for special-shaped CFST columns coupled with multiple cavities under axial compression

异形截面多腔钢管混凝土柱截面形状不规则,受力复杂,其承载力不能按常规钢管混凝土柱计算方法计算。基于已有的6个两类截面的异形截面多腔钢管混凝土巨型柱轴压承载力试验结果,在分析评价国内外规范或规程承载力计算方法基础上,对异形截面多腔钢管混凝土柱轴压承载力计算方法进行研究。结果表明:相关规范或规程中按非圆形截面钢管混凝土柱计算公式所得轴压承载力大多低于试验值,偏于安全;基于Mander约束混凝土模型,将混凝土划分为有效和非有效约束区,提出了考虑折减约束效应的承载力计算式,计算所得承载力值略高于实测值,但相对差值在5%以内。

Due to irregular cross-sectional shape and complex compressive behavior of special-shaped CFST column coupled with multiple cavities, the bearing capacity can＇ t be calculated by the method suiting to regular shaped CFST columns. In this paper, on the basis of the tested bearing capacity results of six special-shaped CFST columns coupled with multiple cavities including two kinds of cross-sectional shapes under axial compression, calculation method analysis and evaluation in available specifications and codes were conducted. Moreover, the bearing capacity calculation method specifically for special-shaped CFST columns coupled with multiple cavities was studied. Research shows that most bearing capacity calculated by non-circular CFST column formulas in available specifications or codes are lower than the test values, and are safe in design. Based on Mander＇ s confined concrete model, the confinement effect is took into accounted by dividing concrete into effective and ineffective confined regions in the proposed method. The calculated bearing capacity are a little more than the test values, but the relative errors are within 5 %.