预应力钢绞线加固RC柱抗震延性研究  

Research on Seismic Ductility of RC Column Strengthened Prestressed Steel Wire

作　　者：曹忠民[1] 林鹤云 CAO Zhongmin;LIN Heyun(East China Jiaotong University, Nanchang 330013,China)

机构地区：[1]华东交通大学土木建筑学院,南昌330013

出　　处：《结构工程师》2017年第5期103-110,共8页Structural Engineers

基　　金：国家自然科学基金项目(05168019)

摘　　要：为了研究预应力钢绞线加固柱的抗震延性,对12个在低周反复荷载作用下的钢筋混凝土圆柱试件进行了数值模拟分析,其中3个为未加固对比柱试件,另外9个为预应力钢绞线加固柱试件,主要考虑了预应力水平和轴压比两种参数对加固柱抗震延性的影响。通过考虑预应力水平对钢绞线约束折减系数的影响,对混凝土本构模型进行改进,并对钢筋采用非线性随动强化模拟,使模拟结果与试验结果吻合较好。研究结果表明:采用钢绞线加固后柱的抗震延性明显提高,也可适当提高柱的轴压比限制;预应力水平的提高对加固柱抗震延性不利,但相比未加固柱仍有所提高;当预应力水平大于0.6时,预应力水平的提高对加固柱抗震延性不利影响趋于平缓。通过考虑轴压比、预应力水平、剪跨比和总体配箍特征值对抗震延性的影响,提出相应的延性计算公式,可供工程设计参考。To study the seismic ductility of circular reinforced concrete(RC)columns strengthened with prestressed steel wire,twelve circular RC columns including three contrast columns and nine columns strengthened with prestressed high strength steel wire were analyzed with main parameters being the prestressing level and axial compression ratio under cyclic loading and constant axial load.Concrete constitutive model was improved by considering the influence of prestressing level reduction factor of steel wire constraints and steel was simulated using nonlinear servo reinforcement,which made the simulation results agree well with the test results.The results show that the seismic ductility of RC columns was obviously improved by using steel wire to strengthen and the axial compression ratio limit of RC columns can appropriately be increased.With the improvement of prestressing level,the seismic ductility of RC columnswas reduced,but compared with contrast columns,it was still increased.When prestressing level is greater than0.6,the negative impact of the seismic ductility of RC columns flatten out with the increase of prestressing level.By considering the axial compression ratio,prestressing level,shear span ratio and overall stirrup characteristic value influence on seismic ductility,the proposed formula of ductility can be used for reference in the engineering design.

关 键 词：预应力钢绞线 钢筋混凝土柱 骨架曲线 预应力水平 轴压比 抗震延性 

分 类 号：TU352.11[建筑科学—结构工程] TU375.3