非对称十字形配钢型钢混凝土矩形截面柱抗震性能试验研究

为适应型钢混凝土(steel reinforced concrete, SRC)框架结构在边柱、角柱部位不均匀受力的特征，并简化施工、避免大量型钢开孔和钢筋焊接，提出非对称十字形配钢SRC矩形截面柱构造。开展7根非对称十字形配钢SRC矩形截面柱和1根对称十字形配钢SRC矩形截面柱的低周往复加载试验，分析配钢形式、剪跨比、轴压比和体积配箍率等主要设计参数对柱抗震性能的影响。结果表明：不对称配钢形式使SRC柱的正、负向承载力不对称，正向加载(型钢内缩侧受压)比负向加载先达到峰值荷载；在相同含钢率下，非对称十字形配钢SRC矩形截面柱可达到与对称配钢形式相近的抗震性能；剪跨比的增大使柱的刚度衰减率降低，延性增加，耗能能力提高；增大轴压比，柱刚度退化加剧，延性降低，耗能能力减弱；提高体积配箍率将改善柱的耗能能力和延性。

Experimental study on seismic behavior of steel reinforced concrete rectangular column with unsymmetrical cross-shaped steel section

In order to adapt to the characteristics of uneven stress on the side and corner columns of steel reinforced concrete (SRC) frame structures, simplify the construction, and avoid a large number of steel openings and steel welding, SRC rectangular column with unsymmetrical cross-shaped steel section was proposed. Low cyclic loading tests were carried out on seven asymmetric and one symmetric SRC rectangular columns with cross-shaped steel section. The effects of steel configuration, shear span ratio, axial compression ratio and volume stirrup ratio on seismic performance of columns were investigated. The results show that the asymmetrical steel distribution makes the positive and negative bearing capacity of the SRC column asymmetrical, and the positive loading (compression on the inner side of the section steel) reaches the peak load earlier than the negative loading. Under the same steel ratio, SRC rectangular columns with unsymmetrical cross-shaped steel section can achieve similar seismic performance to the symmetrical steel form. The increase of shear span ratio reduces the stiffness decay rate of the column, increases the ductility and improves the energy dissipation capacity. With the increase of axial compression ratio, the stiffness degradation of column becomes worse, ductility decreases and energy dissipation capacity weakens. The energy dissipation capacity and ductility of the column can be improved by increasing the volume stirrup ratio.