钢筋混凝土方形柱延性性能及轴压比限值研究

根据钢筋混凝土双向压弯柱的受力性能，采用非线性分析方法，对16 539根方形柱截面的延性进行数值分析，研究了荷载角、轴压比及箍筋配置等因素对柱截面延性的影响，得到方形柱截面延性的主要影响因素是箍筋配置和轴压比；分析各影响因素对柱截面延性变化规律。结果表明：随着轴压比的提高，柱截面延性下降；体积配箍率相同时，采用较小的箍筋直径及箍筋间距比采用较大的箍筋直径及箍筋间距的试件延性好；箍筋间距、箍筋直径不同时，只有同时考虑箍筋间距对纵向钢筋的支撑长度，提高体积配箍率，才能有效地提高柱的截面延性。通过对柱截面延性的回归分析得到了与配箍特征值相关的方形柱的轴压比限值。

Research on limiting value of axial compression ratio and ductility behavior of RC square column

According to the principle of biaxially eccentric loading for RC column and nonlinear analysis,ductility of 16 539 square columns’ section were calculated and analyzed,including many relevant factors including direction angle of action of bending moment,axial force ratio and scheme of lateral reinforcement etc.The dominating factors of ductility of square columns were obtained in terms of axial compression ratio and arrangement of hoop reinforcement.Ductility behavior of square columns were summarized.The following conclusions are drawn.With increased axial compression ratio,ductility of square column is down.When the volumetric ratio of reinforcement for the stirrups or hoops is same,columns’ ductility with arrangement of lesser diameter stirrup and space between hoops is more than bigger diameter stirrup and space between hoops.On the other hand,only considering longitudinal bar of brace length at the same time,improving the volumetric ratio of reinforcement of the stirrups or hoops with different diameter stirrup and space between hoops will effectively improve columns’ ductility.On the base of regression analysis for the ductility of square columns’,the limiting value of axial compression ratio of square column is obtained in relation with characteristic value of providing stirrup or hoop.