高轴压比密配箍筋框架柱抗震性能研究

Research on seismic performance of frame column with dense stirrups and high axial compression ratio

为研究高轴压比下箍筋强约束钢筋混凝土柱的抗震性能,完成了3根配箍特征值0.22-0.44的钢筋混凝土柱的拟静力试验。试验表明：配置加密箍筋能有效提高高轴压比钢筋混凝土柱的抗震性能,水平承载力有一定提高,延性有较大程度改善,配置加密箍筋的RC框架柱的耗能能力明显高于未加密箍筋的柱。基于Msc.marc的THUFIBER程序对试件进行模拟,模拟结果与试件结果吻合较好。同时,对不同轴压比、不同配箍特征值构件的延性进行分析,通过对计算数据的回归分析,得出了框架柱位移延性系数随配箍特征值、轴压比变化的计算公式。通过与已有试验数据、美国规范ACI318-08、欧洲规范Eurocode 8的比较,论证了本文回归计算公式的合理性,并通过该公式给出了配箍特征值的建议值。

To investigate the seismic behavior of closed confinement reinforced concrete column with high axial compression ratio,three reinforced concrete columns with stirrup characteristic values in the range 0. 22-0. 44 were tested under constant axial load and cyclic lateral force. Test results indicate that the seismic performance of reinforced concrete frame column with high axial compression ratio is improved significantly by the use of dense stirrups,the horizontal bearing capacity and the ductility of column are increased. The energy dissipation capacity of RC frame columns with dense stirrups is obviously greater than the contrastive column. Using THUFIBER model based on MSC. marc to simulate experimental specimens,the simulation results agree well with the experimental results. At the same time,the ductility performance of specimen columns with different stirrup characteristic values and different compression ratios was analyzed on the basis of the Msc. marc,and a computing formula of the displacement ductility of columns considering axial compression ratio and stirrup characteristic value was obtained by the regression analysis based on the simulation results. Through comparing the results computed by the proposed formula with test data and the results computed by ACI318-08 and Eurocode 8,it is shown that the proposed formula is feasible,and the design recommendation of stirrup characteristic value is made.