高强度螺旋箍筋约束下的高强混凝土圆柱延性分析

目的研究高强度螺旋箍筋约束下的高强混凝土圆柱的延性性能与其影响参数之间的关系．方法利用“截面条带法”，编制了配有高强钢筋的高强混凝土圆柱延性性能的非线性分析程序。对影响其延性的主要参数——轴压比、体积配箍率、箍筋强度、纵筋配筋率等参数的影响规律进行数值分析，揭示该类构件的位移延性系数与其影响参数之间的关系．结果通过大量的数值计算，得到了高强度螺旋箍筋约束下高强混凝土柱的位移延性系数同轴压比、体积配箍率、箍筋强度和纵向钢筋配筋率之间的关系曲线．结论数值计算表明高强混凝土圆柱的延性性能随轴压比的减小、箍筋强度的提高、体积配箍率的加大而增大；部分配置高强度纵向钢筋可明显改善高强混凝土柱的延性；通过对数值计算结果的回归分析并结合试验结果提出了配有高强钢筋的高强混凝土柱的位移延性经验计算公式．

Numerical Analysis on Ductility of Circular HSC Columns Confined with High-Strength Spiral Stirrups

This paper focuses on the numerical simulation and ductility analysis of circular cross-section high-strength concrete(HRC) column confined with high-strength spiral stirrups under low cycles loading.Firstly,a non-linear Mander FEM model was used to simulate numerically behaviors of the column under the repeated loading.Then,the test data were successfully applied to validate the efficiency of the model and the method.The results of theoretical analysis and test data matched very well.Thirdly,the computer program was used to calculate numerically the behaviors of the column according to variable parameters,such as compression ratios,stirrup reinforcements ratios,longitudinal rebar ratio etc.The results revealed the regulations between external forces and internal performances and showed the failure mechanism of the column as well.Based on the results of numerical simulation and test data,a formula for calculating the displacement-ductility coefficient for HRC column confined with high-strength stirrup was put forward.The results of the study show that the ductility of circular HSC columns can be improved with the decreasing of axis pressure ratio,the increasing of the stirrup strength,and the enlarging of the stirrup reinforcements ratio as well.The ductility of circular HSC columns can be effectively improved by the use of the mixed ultra high and normal strength steel bars for the longitudinal reinforcement.