带耗能角钢无黏结预应力预制剪力墙抗震性能

Seismic Behavior of Unbonded Prestressed Tendon Precast Shear Walls with Energy Dissipation Angle Steel

改进了传统无黏结预应力(UPT)装配式墙体的连接构造方式,在墙趾处设置耗能角钢以提升构件的抗侧承载能力和耗能能力等抗震性能。利用有限元软件MSC.Marc对带耗能角钢UPT预制剪力墙进行单元建模,通过已有耗能角钢的试验数据和无黏结预应力墙体验证有限元模型中无黏结预应力筋、耗能角钢本构模型和接触等参数设置的准确性和合理性。通过参数分析研究了耗能角钢张拉控制应力、预应力筋位置、轴压比、参数设置及墙体高度对带耗能角钢UPT墙体延性及水平抗侧承载力的影响。结果表明:与不带耗能角钢UPT墙体相比,带耗能角钢UPT墙体的抗侧承载能力有明显提高,设置耗能角钢能有效降低预应力筋最大应力;随着耗能角钢厚度的增加或者耗能角钢竖向水平群螺栓至角钢外边缘距离的减小,墙体的抗侧承载力将增大;预应力筋偏心率较小时墙体延性较好,较大的偏心率虽然能够提高墙体的抗侧承载能力,但将大幅降低墙体的延性,不利于改善墙体抗震性能。

The connection details of traditional unbonded prestressing tendon(UPT)prefabricated walls were improved.The energy dissipation angle steel was installed at the toe of the wall to improve the lateral bearing capacity and energy dissipation capacity of the members.The element model of UPT prefabricated shear wall with energy dissipation angle steel was built using finite element software MSC.Marc.The accuracy and rationality of parameters setting in finite element model,such as unbonded prestressed tendons,energy dissipation angle steel constitutive model and contact,were verified by experimental data of energy dissipation angle steel and unbonded prestressed wall.The effects of tension control stress,position of prestressing tendon,axial compression ratio,parameter setting and wall height on ductility and lateral bearing capacity of UPT wall with energy dissipation angle steel were studied by parameter analysis.The results show that compared with the UPT wall without the energy dissipation angle steel,the lateral bearing capacity of UPT wall with angle steel is significantly improved.The steel angle can effectively reduce the maximum stress of prestressed tendons.With the increase of the thickness of the energy dissipation angle steel or the decrease of the distance between the vertical horizontal group bolts and the outer edge of angle steel,the lateral bearing capacity of the wall will increase.The eccentricity ratio of prestressing tendons is smaller and the ductility is better.The larger eccentricity ratio can improve the lateral bearing capacity of the wall,but it will greatly reduce the ductility of the wall,which is not conducive to improving the seismic performance of the wall.