钢管约束钢筋混凝土柱与型钢混凝土柱滞回性能试验研究

Seismic behavior of steel-tube reinforced-concrete(STRC) and steel reinforced-concrete(SRC) columns

进行了3组共6个框架柱的滞回性能试验研究,3组试件分别为钢筋混凝土柱(RC柱)、型钢混凝土柱(SRC柱)与钢管约束钢筋混凝土柱(STRC柱);每组2个试件,包括1个剪跨比λ=3.0的中长柱和1个剪跨比λ=1.5的超短柱。3组试件的截面尺寸、柱子长度和轴力相同,且SRC柱与STRC柱的用钢量相同。试验结果表明,RC与SRC超短柱的变形能力不满足现行抗震规范要求。SRC柱的受弯承载力高于STRC柱,但其变形能力、延性和耗能能力低于STRC柱。STRC短柱中,外包钢管不能有效提高短柱的受剪承载力,但外包钢管对核心混凝土的约束作用有效提高了短柱的延性和变形能力。根据试验结果,建议了STRC超短柱的受剪承载力计算方法,可为工程实践提供参考。

In this paper,6 columns were tested to study the seismic behavior of 3 types of columns including reinforced-concrete(RC) columns,steel reinforced-concrete(SRC) columns and steel-tube reinforced-concrete(STRC) columns.The columns were tested under combined constant axial compression and cyclic lateral loads.Each type of columns consisted of 2 specimens with shear span to depth ratio to be 1.5 and 3.0 respectively.The geometry parameters and axial force of these columns were identical,and steel amount of SRC and STRC columns was the same.The test results indicate that the deformation ability of RC and SRC columns with the shear span to depth ratio 1.5 does not meet the requirement of Chinese code for seismic design.The bending strength and shearing strength of SRC columns are higher than those of STRC columns,but the ductility,deformation ability and energy dissipation ability are opposite.The shearing strength of STRC short column is not obviously improved by the outer steel tube,but the deformation ability and ductility are greatly improved due to the confinement of the steel tube to the core concrete.Based on the experimental results,a design method is proposed to calculate the shear strength of STRC columns.