带约束拉杆矩形钢管混凝土柱的偏压性能

进行了7 个带约束拉杆和2个不设约束拉杆矩形钢管混凝土短柱的单向偏心受压试验，主要研究偏心率、约束拉杆水平间距对矩形钢管混凝土短柱偏压性能的影响。试验研究结果表明，约束拉杆的设置有助于提高矩形钢管混凝土偏压短柱的延性，延迟钢管的局部屈曲。带约束拉杆矩形钢管混凝土柱的偏压承载力随偏心率的增大而减小。在相同偏心率下，试件延性随拉杆水平间距减小而增大。采用带约束拉杆矩形钢管混凝土的本构关系，利用条带法对试件承载力进行数值计算，计算结果与试验结果吻合良好。同时，利用国内现有规程GJB4142-2000、DBJ13-51-2003以及CECS159:2004对试件承载力进行计算，规程计算结果总体上低估了带约束拉杆矩形钢管混凝土偏压试件的承载力。

Eccentric Compressive Behavior of Rectangular Concrete-Filled Steel Tube Columns with Binding Bars

Seven rectangular CFT stub columns with binding bars and two without binding bars were eccentrically loaded in compression by considering the parameters such as load eccentricity ratio and binding bar horizontal spacing. Experimental results indicate that binding bars increase the ductility of rectangular columns under eccentric load and delay the local buckling of steel tubes. The ultimate strength decreases with load eccentricity ratios increasing. When load eccentricity ratios are the same, the ductility increases with binding bar horizontal spacing decreasing. A finite-sliced method using the constitutive relationship of rectangular CFT with binding bars is applied to predict the ultimate strength of the specimens. The predicted results agree well with the experimental results. A comparison of the ultimate strengths between tests and design codes GJB4142-2000, DBJ13-51-2003 and CECS159:2004 shows that these design codes conservatively estimate the ultimate strength of eccentrically loaded rectangular CFT stub columns with binding bars.