套箍加固RC轴压中长柱的承载力理论研究

Theoretical Research on Bearing Capacity of Moderate to Long Reinforced Concrete Columns under Axial Compression and Strengthened by Jacketing

为研究套箍加固RC轴压中长柱的承载力理论计算分析方法,采用切线模量理论,根据材料本构关系和内外力平衡条件,推导了套箍加固RC轴压中长柱的弹塑性稳定承载力计算方法。将理论计算结果与试验结果进行了对比分析,结果表明:理论计算值均低于实测值,且二者的偏差在15%以内。根据所推导的计算分析方法,研究了核心柱初始荷载水平β、柱子长细比l0/b、套箍层混凝土强度、套箍层配筋量四种参数对加固柱承载力Nu的影响规律,结果表明:Nu总体上随β增大而减小,当β<0.7时,减小趋势不够明显,β>0.7后,减小趋势变得明显;l0/b对Nu有明显影响,Nu随l0/b的增大而减小,但二者不是线性关系;Nu随套箍层混凝土强度提高而增大,随套箍层配筋量增大而增大。

In order to investigate the theoretical computational analysis method of axial compression bearing capacity of moderate to long reinforced concrete(RC) columns strengthened by jacketing,the elastic-plastic stability and bearing capacity calculation method was derived based on the tangent modulus theory,the material constitutive relation,and the equilibrium conditions for internal and external forces.,The theoretical calculation results were compared with the test results.The results show that the theoretical calculation value is smaller than the measured value,and the deviation between them is within 15%.According to the derived computational analysis method,the effect of four parameters on the bearing capacity Nu of the strengthened column were investigated,including the initial load level βof the core column,column slenderness ratio l0/b,concrete strength of the hoop layer,and quantity of reinforcement in the hoop layer.The results show that Nu generally decreases with the increase of β.When β<0.7,the decreasing trend is not obvious enough.If β>0.7,the decreasing trend becomes apparent.The effect of l0/b on Nu is obvious,and Nu decreases nonlinearly with the increase of l0/b.Nu increases with the increase of hoop layer concrete strength.Nu also increases with increased quantity of reinforcement in the hoop layer.