钢管混凝土格构柱偏心受压面内极限承载力分析

Analysis on ultimate load carrying capacity of concrete filled steel tubular laced columns compressed eccentrically

应用钢管混凝土结构设计规程,对钢管混凝土格构柱偏心受压试件进行面内整体承载力计算。计算结果与试验值相差较大。规程在计算换算长细比时采用加法来考虑剪切变形的影响,对于长细比较小的构件,将过度考虑剪切变形对承载力的不利影响,且出现承载力几乎不随构件长细比的变化而变化的不合理现象。在借鉴国外钢格构柱计算方法的基础上,提出采用放大系数法来计算钢管混凝土格构柱的换算长细比,所得极限承载力与试验值吻合良好。

The in-plain ultimate load carrying capacity of concrete filled steel tubular （CFST） laced columns compressed eccentrically is calculated based on design guidelines for CFST structure. There is a significant difference between the calculation results and the test results. According to the guidelines, equivalent slenderness ratio of laced column is calculated by an additive method to take into account the influence of shear defonnation on ultimate load carrying capacity of lacing members. In this method, the shear influence is overestimated for those members with small slenderness ratio and may produce an unreasonable result that ultimate load carrying capacity hardly changes with the increase of slenderness ratio of members. A method by using an amplification parameter to calculate equivalent slenderness ratio of CFST laced columns is presented. The calculation results of ultimate load carrying capability by this method are compared favorably with test results.