方钢管混凝土短柱轴压极限承载力计算方法分析

Analysis on calculating method of ultimate bearing capacity of concrete-filled square steel tube short columns under axial load

从方钢管对混凝土的约束机理出发,分析了组成方钢管混凝土短柱各部分的应力状态,将方钢管对核心混凝土的约束作用等效为有效侧向应力,利用复杂应力下钢材及混凝土极限(屈服)条件,基于极限平衡理论,建立了柱截面的力学平衡方程,推导了该柱的轴压极限承载力计算公式。应用推导公式对42根方钢管混凝土短柱试件的轴压承载力进行计算,比较计算结果与试验结果,两者吻合良好。

Based on the constraint mechanism of concrete from the square steel tube,the stress states of various parts of concrete-filled square steel tube columns were analyzed.The restraint effect of core concrete from square steel tube was equivalent for the effective lateral stress.Using ultimate(yield) conditions of steel and concrete under the complex stress,mechanical equilibrium equation of columns section was established based on the limit equilibrium theory.And the calculation formula of axial compression ultimate bearing capacity of the columns was derived.The axial compression bearing capacities of 42 concrete-filled square steel tube columns were calculated using proposed formula.Results show that the test results are in good agreement with the calculation results.