矩形钢管混凝土柱-混凝土梁穿筋节点力学性能试验研究EI北大核心CSCD

针对矩形钢管混凝土柱-混凝土梁连接节点在高层建筑工程中存在传力不直接,施工难度大,施工质量难以保证的问题,结合北京CBD核心区Z13地块超高层项目,提出了矩形钢管混凝土柱-混凝土梁穿筋节点,对不同配筋率的矩形钢管混凝土柱-混凝土梁穿筋节点试件进行低周往复加载试验,研究节点的滞回性能、破坏形态、耗能能力和延性等力学性能。并与传统的矩形钢管混凝土柱-混凝土梁焊接牛腿式连接节点和矩形钢管混凝土柱-混凝土梁套筒牛腿式连接节点进行性能对比。在试验基础上,对矩形钢管混凝土柱-混凝土梁穿筋节点受力性能进行理论分析并推导适用的设计公式。结果表明:矩形钢管混凝土柱-混凝土梁穿筋节点与另外两种类型节点相比有较强的承载能力,能够满足“强节点,弱构件”及传递竖向荷载的结构设计要求,并且便于施工、质量可靠。在此基础上进行理论分析,提出节点受弯承载力设计公式并推荐型钢牛腿截面按照承担梁端剪力80%进行截面设计,为矩形钢管混凝土柱-混凝土梁穿筋节点设计提供技术支撑。

EXPERIMENTAL STUDY ON THE MECHANICAL PROPERTY OF STEEL BAR-PIERCED JOINTS OF RC BEAMS AND RECTANGULAR CONCRETE-FILLED STEEL TUBULAR COLUMNS

To overcome the problems of RC beam-and-rectangular concrete-filled steel tubular column joints in high-rise buildings such as the indirect force transmission, complex construction and unguaranteed construction quality, a steel bar-pierced joint of RC beams and rectangular concrete-filled steel tubular columns was proposed for the Z13 project of the Beijing CBD core area. Low-cycle reciprocating loading tests were performed on the steel bar-pierced joints of RC beams and rectangular concrete-filled steel tubular columns with different reinforcement ratios to study the hysteretic performance, failure mode, energy dissipation capacity and ductility, which were compared with those of the conventional welded bracket joints and the joints of sleeves and brackets for RC beams and rectangular concrete-filled steel tubular columns. Based on the experimental results, the theoretical analysis of the mechanical properties of the steel bar-pierced joints of RC beams and rectangular concrete-filled steel tubular columns was conducted. Practical design formula were derived. It was indicated that the steel bar-pierced joint of RC beams and rectangular concrete-filled steel tubular columns had higher bearing capacity than the other two types of joints, which could meet the structural design requirements of 'strong joints and weak components' and vertical load transmission. They are convenient to construct and reliable in quality. On this basis, the design formula for the bending bearing capacity of the joint is proposed. The section design of the steel corbel section is recommended to bear 80% of the beam end shear force to provide technical support for the optimization of the design of the rectangular concrete-filled steel tubular column-concrete beam through-reinforced joints.