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试验中设计了一组圆钢管约束钢筋混凝土(CTRC)短柱,对其进行恒定轴压力作用下的拟静力试验研究,主要试验参数为径厚比、轴压比和剪跨比。试验得到了CTRC短柱在水平地震作用下的剪切破坏模式。结果表明:剪跨比为1.3和1.8的短柱分别发生了剪切破坏和弯曲破坏;外包钢管对核心混凝土的约束作用显著提高了短柱的承载力和延性,发生剪切破坏和弯曲破坏短柱的弹塑性极限层间位移角分别超过了4%和6%;CTRC短柱的刚度和水平承载力随轴压比的提高而增大,峰值荷载后,高轴压比剪切破坏短柱的刚度和承载力退化较快,但弯曲破坏短柱退化并不明显;CTRC框架柱发生剪切破坏时钢管受剪面屈服,而发生弯曲破坏时钢管仅端部塑性铰区屈服;破坏模式对钢管的应力状态影响较大。
In the experiment, a set of short columns of circular steel tube constrained reinforced concrete (CTRC) was designed and subjected to quasi-static tests under constant axial pressure. The main test parameters were diameter-thickness ratio, axial compression ratio and shear-span ratio. The shear failure mode of CTRC short column under horizontal earthquake is obtained. The results show that shear failure and bending failure occur in short columns with shear span ratio of 1.3 and 1.8, respectively. The restraint effect of the steel tube on the core concrete significantly increases the bearing capacity and ductility of the short column, resulting in shear failure and short bending failure The elastic-plastic ultimate displacement angles of the columns exceed 4% and 6% respectively. The stiffness and horizontal bearing capacity of the CTRC short columns increase with the increase of the axial compression ratio. After the peak load, the short columns with high axial compression ratio shear failure The stiffness and the bearing capacity degenerate rapidly, but it is not obvious that the bending failure of the short column will be deteriorated. When the shear failure of the CTRC frame column occurs, the shear strength of the steel pipe will be surrendered, but only when the bending failure occurs. Steel pipe stress state greater impact.