劲化方形截面钢管混凝土短柱轴压试验研究

采用劲化方形截面钢管混凝土柱可以有效地提高柱钢管壁的侧向刚度，增强其抵抗局部屈曲的能力和改善对核心混凝土的约束作用。通过普通方形截面钢管混凝土柱和劲化方形截面钢管混凝土短柱的轴压试验，对柱的轴压破坏形态、轴力-变形特征、钢管应变等进行了分析。结果表明：劲化带的设置使钢管壁对核心混凝土的约束作用更趋均匀，改变了钢管的局部屈曲变形状态，明显提高了方形截面钢管混凝土柱的轴压承载力和变形能力。根据劲化方形截面钢管混凝土短柱的受力分析，提出了轴压承载力计算式，计算结果和试验结果吻合良好。

Experimental study on axial compression behavior of stiffened square section CFST short columns

By setting stiffening belts, the lateral stiffness of the steel tube of square section CFST columns is effectively improved, the resistance capacity of the local buckling of the steel tube is enhanced, and then the bearing capacity and the ductility of the columns are improved. The axial compression experiments of the ordinary square section and the stiffened square section CFST short columns were carried out. The characteristics of the failure, deformation, bearing capacity, strain of the steel tube of the columns were analyzed. The experimental results show that by setting the stiffening belts the confinement effects of the steel tube to core concrete become stronger and more uniform and the local buckling mode of the steel tube are changed. The axial compression bearing capacity and deformation capacity of the columns are significantly increased. The calculating method is put forward for the axial compression bearing capacity according to the mechanical analysis of the stiffened section square CFST short columns. The calculating results are in good agreement with the experimental results.