带开孔损伤钢管混凝土轴压性能试验研究

EXPERIMENTAL STUDY ON MECHANICAL PROPERTIES OF CONCRETE-FILLED OPENING HOLE DAMAGED STEEL TUBULAR MEMBERS

为了研究开孔损伤钢管混凝土的力学性能,对14根开孔损伤钢管混凝土构件进行轴压试验研究,考虑开孔损伤率、混凝土强度等级、长细比等变化参数,观察试件的受力全过程及破坏形态,获取开孔损伤钢管混凝土的破坏机理、荷载-变形以及应力-应变曲线,分析开孔损伤率、混凝土强度等级、长细比等变化参数对开孔损伤钢管再生混凝土承载能力及变形性能的影响。研究结果表明:开孔损伤钢管混凝土构件加载后期延性较好,其破坏形式大多为钢管鼓曲后撕裂破坏,开孔损伤率对试件的破坏形态和极限承载力有着不同程度的影响。最后对带损伤钢管混凝土的承载能力计算方法进行探讨,利用现有普通钢管混凝土规范方法进行计算,结果表明,在开孔损伤率(小于0.8%)不大的情况下,现有钢管混凝土规范方法计算结果还是安全的。

In order to study the mechanical properties of concrete-filled opening hole damaged steel tubular members,14 concrete-filled opening hole damaged steel tubular specimens were designed for the axial compressive test.The change parameters of opening damage rate,concrete grade strength,slenderness ratio were considered.Through this test,the whole mechanical process and failure pattern of all specimens were observed,the failure mechanism,load-deformation and stress-strain curves of concrete-filled opening hole damaged steel tubular specimens were obtained,The influence of change parameters including opening damage rate,concrete grade strength,slenderness ratio on the mechanical properties of concrete-filled opening hole damaged steel tubular members were analyzed.Test results indicated that the specimens in the loading late stage had good ductility;the failure pattern was the local buckling and tear failure.The opening damage rate of the specimens has some degree of impact on the failure pattern and ultimate bearing capacity.Finally the calculation method of bearing capacity of concrete-filled opening hole damaged steel tubular was discussed,based on the formulas of existing criteria,and the result showed that while the opening damage rate was not big（ 0.8%）,the calculated results by the existing standard methods of concrete-filled steel tubular were safe.