论文部分内容阅读
介绍15个带约束拉杆方形钢管混凝土短柱和8个带约束拉杆矩形钢管混凝土短柱的轴压试验结果,分析钢管壁厚度、拉杆直径、拉杆水平间距等参数对其轴压性能的影响。试验研究结果表明,约束拉杆的设置有助于延迟钢管的局部屈曲、提高方形钢管混凝土短柱的轴压承载力和延性,提高矩形钢管混凝土短柱的延性。约束拉杆的作用主要表现为对核心混凝土的约束作用及通过改变钢管侧壁局部屈曲的边界条件从而提高钢管的屈曲强度。同时,在合理考虑拉杆作用的基础上,应用等效侧向压力的概念和基于混凝土真三轴试验的破坏准则确定核心混凝土的峰值强度,提出带约束拉杆方形、矩形钢管混凝土短柱轴压承载力的计算方法,承载力计算结果与试验结果吻合良好。
The axial compression test results of 15 concrete-filled square concrete-filled steel tubular columns with constrained tie rods and 8 rectangular concrete-filled steel tubular columns with constrained tie rods are introduced. The effects of parameters such as the thickness of steel pipe wall, tie rod diameter and tie rod horizontal spacing on the axial compression properties are analyzed. The experimental results show that the restraining rod can help to delay the local buckling of the steel tube, increase the axial compressive bearing capacity and ductility of the concrete filled square steel tube, and improve the ductility of the concrete filled rectangular steel tube column. Constraints of the restraining lever mainly show the restraint effect on the core concrete and the buckling strength of the steel pipe by changing the boundary conditions of the local buckling of the steel pipe sidewall. At the same time, based on the reasonable consideration of tie rod’s effect, the concept of equivalent lateral pressure and the failure criterion based on true triaxial test of concrete were used to determine the peak strength of core concrete. The axial compression bearing of square and rectangular CFST with restrained tie rod The calculation method of force and bearing capacity are in good agreement with the experimental results.