螺旋筋约束增强空腹式型钢混凝土柱滞回性能试验研究

为了研究螺旋筋约束增强空腹式型钢混凝土柱的滞回性能，以轴压比、配箍率、配钢形式以及截面形式为变化参数，设计10个试件（其中空腹式型钢混凝土柱对比试件1个，复合螺旋箍筋混凝土柱对比试件1个）进行低周反复加载试验。观察试件的破坏形态，获取各试件的滞回曲线和骨架曲线。分析试件的极限承载力、层间位移角、延性、耗能、强度衰减和刚度退化等抗震性能指标，以及各变化参数对其抗震性能的影响。结果表明：螺旋筋约束增强空腹式型钢混凝土柱主要表现为弯曲破坏和黏结破坏；相比空腹式型钢混凝土柱和复合螺旋箍筋混凝土柱，螺旋筋约束增强空腹式型钢混凝土柱的滞回曲线更为饱满，承载力、延性和耗能均有提高；随着轴压比的增大，其承载力、刚度和耗能能力提高，但延性和变形能力降低，强度衰减和刚度退化现象更为严重；随着螺旋箍筋配箍率的增大，承载力、刚度、延性、耗能能力和变形能力逐渐提高；相同总含钢量下，增大螺旋筋配箍率比增大型钢间接配钢率对其延性和耗能能力的提高更显著，对其承载力则相反；三种截面形式中，Ⅲ类截面试件表现出最优的抗震性能。

Experimental study on hysteretic behavior of spiral confined lattice steel reinforced concrete columns

To investigate the hysteretic behavior of spiral-confined lattice steel reinforced concrete (SLSRC) columns, 10 specimens including one reference specimen of lattice steel reinforced concrete column and one reference specimen of spiral stirrup reinforced concrete column were designed and subjected to lateral cyclic load. The axial compression ratio, stirrup reinforcement ratio, indirect reinforcement mode and type of cross section were considered to design the specimens. The failure modes, hysteretic curves and skeleton curves were obtained. The ultimate load-carrying capacity, floor displacement angle, ductility, energy dissipation, strength drop-off and stiffness degeneration of the specimens were studied and analyzed. Results showed that the flexural failure and bond failure were main failure modes for SLSRC columns. The hysteretic curves of SLSRC columns were fuller and the ultimate load-carrying capacity, ductility and energy dissipation were higher, compared to that of lattice steel reinforced concrete column and spiral stirrup reinforced concrete column. The ultimate load-carrying capacity, stiffness and energy dissipation capacity were increased, but the ductility and deformability were decreased. The strength drop-off and stiffness degeneration were severer with the increase of axial load ratio. With the increase of spiral stirrup reinforcement ratio, the ultimate load-carrying capacity, stiffness, ductility, energy dissipation and deformability increased gradually. Increasing the spiral stirrup reinforcement ratio has better effect than increasing the steel batten ratio for the improvement of ductility and energy dissipation. However, it is opposite for the increase of load-carrying capacity. The type Ⅲ SLSRC column exhibited the best mechanical properties in all kind of SLSRC columns.