长细比对螺旋箍筋柱轴心受压承载力的影响

在GB 50010—2010《混凝土结构设计规范》中，螺旋箍筋柱轴心受压承载力计算公式未能定量反映长细比的影响，与普通箍筋柱计算公式及国内外其他有关规范公式的差异较大。为了定量分析长细比对螺旋箍筋柱轴心受压性能的影响，基于ANSYS软件建立了钢筋混凝土螺旋箍筋柱的精细化弹塑性有限元模型，采用经过验证的有限元模型开展了不同直径和长径比的螺旋箍筋柱轴心受压加载破坏过程的有限元分析。结果表明：螺旋箍筋柱的承载力随着核心区长径比的增大而逐渐降低，当长径比由2增大至5时，其承载力降低幅度在3.7%以内；当长径比达到15时，其承载力较长径比为2时相应值降低了25%。在计算分析的基础上，提出了螺旋箍筋柱轴心受压承载力计算公式中稳定系数的取值建议。

Influence of slenderness on axial compressive bearing capacity of spirals reinforced concrete column

The calculation formula for the axial compressive strength of spiral reinforced concrete columns specified in GB 50010—2010 ‘Code for design of concrete structures’ does not quantify the influence of slenderness on the compressive strength of the column. The codified equation is not consistent with that for normal reinforced concrete columns in the related specifications of technical standards at home and abroad. To quantitatively analyze the influence of slenderness on the axial compressive behavior of spiral reinforced concrete columns, refined elasto-plastic finite element models were established for spiral reinforced concrete columns based on ANSYS software, and FE analysis were carried out based on the validated FE model to obtain the failure process of the spiral reinforced columns with different diameter and length diameter ratio under axial compression. The results demonstrate that the axial compressive strength of the spiral reinforced column decreases with the increase in the core’s length diameter ratio. The axial compressive bearing capacity of the spiral reinforced column is decreased by less than 4% when the core’s length diameter ratio increases from 2 to 5, and the corresponding bearing capacity decreases by more than 25% when the reaches 15. A calculation formula giving the axial compressive bearing capacity of spiral reinforced column were proposed, and the corresponding stability coefficients were suggested based on a regression analysis of the simulated results.