带肋薄壁方钢管混凝土轴压短柱设计探讨

薄壁方钢管混凝土能取得较好的经济效果,适宜在结构中用作柱构件。但薄壁钢管在荷载较大时易发生局部屈曲,且降低对混凝土的约束。研究表明,在钢管纵向设置加劲肋可有效延缓管壁局部屈曲,改善构件工作性能。针对该新型方钢管混凝土轴压短柱,探讨子板件最大宽厚比及加劲肋的最小刚度确定方法。最后利用国内外常用的钢管混凝土设计规范对已有充分加劲的试验构件进行承载力计算,通过分析比较确定这些规范计算公式的适用性,供工程实践参考。

DESIGN OF CONCRETE-FILLED THIN-WALLED STIFFENED STEEL TUBULAR STUB COLUMNS WITH SQUARE SECTIONS

Concrete-filled thin-walled square steel tubes are becoming more and more attractive to be used in engineering practice, for reasons of saving construction time and costs. However, local buckling is more likely to occur for thin-walled tubes, and thus decreases the lateral confinement on the concrete core. In order to improve the performance of such kind of composite columns, the effectiveness of longitudinal stiffeners welded on the steel tubes has been studied in recent years, which demonstrates the fact that the stiffeners can effectively delay the tube local buckling, and improve the serviceability of composite members. This paper discusses the allowed width-to-thickness ratio of the sub-panels and the rigidity requirement of the stiffeners used in stiffened composite stub columns. To evaluate the feasibility of currently available design codes in predicting the load-carrying capacity of the stiffened composite stub columns, the bearing capacities predicted using those design codes are compared with the currently available test results of adequately stiffened stub columns.