基于OpenSees仿真的自复位预制装配RC桥墩抗震性能分析

Seismic Performance Analysis of Self-centering Precast RC Bridge Columns Based on OpenSees

将震后可恢复功能设计新理念和预制装配桥梁建造新技术相结合,在已开展自复位预制装配式RC桥墩结构拟静力往复加载试验基础上,基于OpenSees软件平台建立了自复位预制拼装RC桥墩的数值模型.数值仿真了水平往复加载作用下自复位预制桥墩力学行为并与模型试验结果进行了对比验证.参数化分析了预制桥墩高宽比、轴心后张预应力筋面积和初始张拉力等关键设计参数对自复位预制桥墩抗震性能的影响.结果表明,本文基于OpenSees建立的数值模型可较好地模拟自复位桥墩的拟静力往复力学行为.随墩柱高宽比增大,预制桥墩侧向初始刚度、屈服后刚度、承载力迅速下降,滞回曲线也越来越不饱满,耗能能力变弱.随轴向预应力筋初始张拉应力增加,桥墩屈服承载力增加,但对屈服后刚度无明显影响.轴向预应力筋面积对桥墩屈服承载力基本无影响,但对桥墩屈服后刚度影响显著,且大致呈正相关特性.

Combining the design concept of the seismic resilience with precast bridge technology,a numerical model using OpenSees software was developed in this study to simulate the seismic performance of precast self-centering bridge columns.The proposed numerical model of precast self-centering bridge columns was validated throguh the quasi-static test data.Parametric studies were performed in terms of aspect ratio,the areas and initial tensioning force of axial post-tensioned steel strands.It is concluded that,with the increase of aspect ratio of the precast self-centering bridge columns,the initial stiffness,post-yield stiffness,lateral strength and energy dissipation capacity decreased.As initial tensionforce increased,the yield strength increased,while the effect on the post-yield stiffness was negligible.The area of post-tensioned steel strands imposed marginal effect on the yield strength,but significant effect on the post-yield stiffness with an approximate positive correlation.