组合T形截面钢管混凝土柱正截面受压承载力试验研究

Experimental study on normal section compression bearing capacity of composite T-shaped concrete-filled steel tubular columns

在总结分析各种异形钢管混凝土柱工程应用的基础上,提出矩形钢管混凝土组合焊接T形柱(WeldedRectangular Composite T-shaped Concrete-Filled Steel Tubular Column,简称WRC-T钢管混凝土柱)。考虑约束效应系数、长径比、肢长腹比等参数的影响,设计制作34个WRC-T钢管混凝土柱试件;通过轴心受压试验,考察试件的破坏形态,实测试件的荷载-纵向应变曲线、强度承载力和稳定承载力,分析各参数对此类试件轴心受压力学性能的影响。通过试验数据回归分析,参考国内外相关规范的计算条文,提出WRC-T钢管混凝土柱轴心受压强度承载力和稳定承载力的实用计算公式。研究表明,WRC-T钢管混凝土柱的两个组成部分能很好地协同工作,力学性能好;长径比L/i≤14.4的试件可视为短柱,长径比14.4<L/i≤33.6的可视为中长柱。文中所提强度承载力和稳定承载力公式的计算结果与试验值符合良好,可供工程设计参考。

Based on a review of the application of various types of special shaped concrete-filled steel tube columns, a Welded Rectangular Composite T-shaped （WRC-T） concrete-filled steel tubular column is proposed. A total of 34 WRC-T concrete-filled steel tube short columns were designed and manufactured with Consideration of such factors as the restriction factor, length-diameter ratio and component length to web width ratio. Axial compression tests were carried out and the load-deformation curves and the ultimate bearing capacity were determined and the failure patterns of the specimens were investigated. The effect of each of the factors on the mechanical properties of the short columns was analyzed. With reference to the domestic and oversea design codes, a formula for determining the axial compression bearing capacity of the WRC-T concrete-filled steel tubular columns was proposed through regression analysis of the test data. The results indicated that the WRC-T short concrete-filled steel tube columns composed of two rectangular steel tube columns can effectively work together. The calculation results from the proposed formula agree well with the test results.