圆钢管约束钢筋自应力钢渣混凝土柱恢复力模型研究

Research on Restoring Force Models of Reinforced Self-Stressing Steel Slag Concrete Columns Confined with Circular Steel Tubes

开展了10根圆钢管约束钢筋自应力钢渣混凝土柱和4根圆钢管约束钢筋钢渣混凝土柱的低周反复加载试验,分析了轴压比、剪跨比、径厚比和钢渣混凝土膨胀率对试件破坏形态和滞回性能的影响。结果表明,所有试件均发生弯曲破坏,破坏范围集中于预留缝区域。随着轴压比和径厚比减小,或剪跨比和钢渣混凝土膨胀率增大,试件的荷载-位移滞回曲线饱满度提高。试件承载力随着轴压比、径厚比和核心钢渣混凝土膨胀率增大而增大,而侧向变形能力随着轴压比和径厚比增大有所降低。随后,在试验研究基础上,考虑轴压比、剪跨比、径厚比和钢渣混凝土膨胀率的影响,提出试件荷载-位移骨架曲线特征点简化计算公式。并基于退化三线型恢复力模型,提出试件滞回规则,建立其荷载-位移恢复力模型,恢复力模型计算结果与试验值吻合良好。

The seismic performence of ten reinforced self-stressing steel slag concrete columns confined with circular steel tubes and four reinforced steel slag concrete columns confined with circular tubes under quasi-static loading were tested.The effects of axial compression ratio,shear-span ratio,diameter-thickness ratio and expansion rate on the failure mode and hysteretic behavior were analyzed.The results showed that the flexural failure was observed in all specimens,and the damage was concentrated in the reserved gap.The fullness of the hysteretic curves increased as the decrease in the axial compression ratio,diameter-thickness ratio or the increase in the shear-span ratio and the expansion rate.The bearing capacity of the specimens increased with the increase of the axial compression ratio,diameter-thickness ratio and expansion rate,while the lateral deformation capacity decreased with the increase in axial compression ratio and diameter-thickness ratio.Subsequently,based on the experiment results,the simplified load-displacement skeleton curves were proposed considering the effects of axial compression ratio,shear-span ratio,diameter-thick-ness ratio and expansion rate.Moreover,according to the degraded tri-linear restoring force model,the hysteretic rules of the specimens were proposed,the restoring force model for reinforced self-stressing steel slag concrete columns confined with circular steel tubes was established,and the calculated results of the restoring force model were in good agreement with the experimental values.