FRP约束钢筋混凝土矩形空心桥墩的滞回模型

Hysteretic Model of FRP Confined RC Bridge Pier with Rectangular Hollow Section

为了评价纤维增强复合材料(FRP)约束钢筋混凝土(RC)空心桥墩的抗震性能,对4根FRP约束矩形空心桥墩进行了水平单向低周反复荷载作用下的拟静力试验研究,及相应的FRP约束矩形空心截面弯矩-曲率数值分析。根据FRP约束矩形空心桥墩实测滞回曲线的特点和FRP约束矩形空心截面弯矩-曲率的模拟结果,基于现有RC柱的弹塑性滞回模型,提出了四折线水平位移-力骨架曲线模型及相应受力阶段滞回规则下的滞回模型。结果表明:新的滞回模型可正确反映FRP约束矩形空心桥墩的有效刚度衰减、反向加载规则和捏缩效应,其FRP约束矩形空心桥墩的水平位移-力计算滞回曲线与试验结果吻合良好。

In order to estimate the seismic performance of the fiber reinforced polymer （FRP）confined RC bridge piers with hollow section, the quasi-static test was carried out on four FRPconfined RC bridge piers with rectangular hollow section under unidirectional horizontal load, andnumerical simulation method was applied to analyze the moment-curvature relationship of FRPconfined RC rectangular hollow sections corresponding to the tested bridge piers. In view of theexperimental hysteretic curves＇ characteristics of the FRP confined RC bridge piers with hollowsection and simulated moment-curvature results of FRP confined RC rectangular hollow section,based on the existing elastic-plastic hysteretic models of RC columns, a curve model of horizontaldisplacement-force with four-polyline skeleton curve a hysteretic model under hysteretic rules forcorresponding loading stages were proposed. The results show that the proposed hysteretic modelcan correctly present the effective stiffness declining, reverse loading rules and pinch effect ofFRP confined RC bridge pies with rectangular hollow section and the calculated results agree wellwith the experimental results.