足尺及实桥圆形钢筋混凝土桥墩抗震性能数值模型与验证

Numerical Model and Verification of Seismic Performance of Full-Scale Mockup and Actual Circular Reinforced Concrete Pier

为建立较可靠的钢筋混凝土桥墩数值分析模型进行抗震性能评估,提出基于OpenSees集中塑性单元和材料本构的纤维截面等效塑性铰模型,对5个足尺及实桥圆形钢筋混凝土桥墩的拟静力或振动台试验结果进行数值模拟,并就关键效应及参数对模拟结果的影响进行分析。结果表明:纤维截面等效塑性铰模型与桥梁抗震规范的集中塑性模型概念一致,具有较强的工程实用性;数值分析结果与拟静力及振动台的试验结果吻合良好,P-Δ效应、纵筋屈曲效应以及纵筋低周疲劳参数的合理取值对模拟结果影响较大;基于纤维截面等效塑性铰模型的截面层次及构件层次的数值模拟均可作为足尺及实桥圆形钢筋混凝土桥墩抗震性能评估的有效方法。

A reliable numerical model is beneficial to the evaluation of seismic performance of reinforced concrete pier.In this paper,a fiber-section equivalent plastic hinge model that is developed based on the lumped-plastic element and material constitutive model in the OpenSees library is proposed.The model was used to simulate the quasi-static or shake table excitations of five full-scale and actual circular reinforced concrete piers,and the influence of the key effects and parameters on the simulation results was analyzed.According to the analysis,the concept of fiber-section equivalent plastic hinge model represents the lumped-plastic in bridge seismic code,which is of wide applicability.The numerical simulation results agree well with the results of quasi-static and shake table tests.The simulation results are more sensitive to the P-Δeffect,buckling effect of longitudinal reinforcement and low-cycle fatigue parameter of longitudinal reinforcement.The numerical simulations that are based on the section level and component level of the fiber-section equivalent plastic hinge model are proved effective methods to evaluate the seismic performance of the full-scale mockup and actual circular reinforced concrete pier.