异形多腔钢管混凝土柱往复轴压性能试验

Hysteretic behavior of special-shaped multi-cell concrete-filled steel tube under reciprocating axial compression

摘要:

为研究内置钢筋笼及内置圆钢管对异形多腔钢管混凝土柱在往复轴压作用下受力性能的影响,进行了3个以Z15大厦为原型的大尺寸异形多腔钢管混凝土柱试件的往复轴压试验,分析了各试件的损伤演化、加卸载全曲线、骨架曲线、承载能力、变形能力、刚度及刚度退化、累积耗能及应变,并采用多国规范对3个试件进行了轴压承载力计算.结果表明:内置钢筋笼能够有效提高试件初始刚度及承载能力；内置圆钢管能够进一步提高试件初始刚度和承载力,且能够显著提高试件的延性、累积耗能能力及后期工作性能；采用各国规范计算得到的承载力结果,因均未考虑横隔板的作用及内外钢板不同的屈服机理,均显著小于试验值。因此需要进一步研究适用于多腔钢管混凝土柱的承载力计算方法,同时,建议实际工程中内置圆钢管来提高异形多腔钢管混凝土柱性能.

Abstract:

To investigate the influence of reinforcement cages and circular steel tube on special-shaped multi-cell concrete-filled steel tube (SMCFST) under reciprocating axial load, three large-size specimens were designed based on Z15 tower. The failure model, load-deformation curves, skeleton curves, bearing capacity, deformation capacity, stiffness degeneration, cumulative energy dissipation, and strain of the specimens were analyzed. Codes of different nations were utilized to calculate the bearing capacity of the specimens. The results shown that the reinforcement cages could enhance the initial stiffness and bearing capacity of the specimens. The circular steel tube could further improve the initial stiffness and bearing capacity, as well as significantly enhance the ductility, cumulative energy dissipation, and the behavior of the specimens at the later stage. Moreover, since the codes ignored the effect of horizontal diaphragms and the different buckling mechanisms between inner steel plate and outer steel plate, the calculation results were significantly lower than the experimental results. Therefore, it was necessary to further investigate the calculation method of the multi-cell concrete-filled steel tube. The circular steel tube was suggested to be used in buildings to improve the axial compression behavior of the special-shaped multi-cell concrete-filled steel tube.