In recent years, the concrete-filled steel tubular (CFST) columns with large cross-sectional aspect ratios have been paid much attention for practical engineering applications. By installing bolts to connect opposite surfaces of the steel tubes in bolt-connected CFST columns, the axial resistant behavior of CFSTs with large cross-sectional aspect ratios can be significantly improved. This paper presented experimental and numerical studies on axial resistant behavior of the bolt-connected rectangular CFST stub columns. In this study, 19 bolt-connected CFST columns were designed and tested under axial compression, and an ordinary CFST column was also tested for comparison. The failure modes, ultimate resistance, residual resistance, and ductile performance of the bolt-connected CFST columns were investigated concerning the effects of key parameters including: (1) cross-sectional parameters, (2) connecting bolts parameters, (3) confining factor of cross sections ξ. The test results indicated that the generation and development of local buckling deformation on the wider side of the steel tube could be delayed by installing bolts, thus the confinement effect of steel tube on the core concrete was improved to achieve better axial resistant and ductile performance. In addition, a refined finite element (FE) model was established using Abaqus, and its validity was verified against tests for conducting an extensive parametric study. According to the experimental and numerical results, it was found that the spacing-to-width ratio, cross-sectional aspect ratio and width-to-thickness ratio of steel tube had significant effects on axial resistant and ductile performance of bolt-connected CFSTs. In addition, a bolt spacing corresponding to s/D ≤ 0.5 was recommended to achieve a satisfactory ductile performance in engineering practice.

近年来，大截面纵横比的钢管混凝土（CFST）柱在实际工程应用中备受关注。通过在螺栓连接的CFST柱中安装螺栓连接钢管的相对表面，可以显着提高具有大横截面纵横比的CFST的轴向抗力性能。本文介绍了螺栓连接矩形 CFST 短柱的轴向抗力性能的实验和数值研究。在本研究中，设计并测试了 19 根螺栓连接的 CFST 柱在轴向压缩下，并测试了一根普通的 CFST 柱以进行比较。失效模式、极限阻力、残余阻力、ξ。试验结果表明，通过安装螺栓可以延缓钢管较宽边局部屈曲变形的产生和发展，从而提高钢管对核心混凝土的约束作用，获得更好的抗轴延性。此外，使用 Abaqus 建立了一个精细的有限元 (FE) 模型，并通过测试验证了其有效性，以进行广泛的参数研究。根据试验和数值结果发现，钢管的间距宽比、截面纵横比和宽厚比对螺栓连接的CFSTs的轴向抗力和延性性能有显着影响。另外，一个螺栓间距对应s / D ≤ 0.5 被推荐在工程实践中获得令人满意的延展性能。