多塑性铰混凝土桥墩增量动力时程分析

Incremental Dynamic Time-history Analysis of Multi-plastic Hinge Concrete Bridge

文章基于桥梁延性抗震设计,提出了一种采用FRP筋梯级配置的多塑性铰混凝土桥墩,该桥墩可形成与外力相适应的承载能力功能梯度,使桥墩于各梯级段底部形成塑性铰。文章采用CFRP筋对桥墩进行梯级配筋,分别设计了双塑性铰、三塑性铰、四塑性铰3种增强方案,并基于增量动力时程分析,将多塑性铰桥墩与普通钢筋混凝土桥墩进行对比,探讨多塑性铰桥墩设计方法对桥梁结构抗震性能的增强效果。研究结果表明,CFRP筋梯级配筋可使桥墩形成多塑性铰破坏,其塑性变形由各塑性铰分担;多塑性铰桥墩的损伤程度发展迟缓,较难达到极限破坏。

Based on the ductile seismic design of bridges,a multi-plastic hinge concrete pier with stepped reinforcement of FRP bars is proposed.The pier can form a functional gradient of bearing capacity adapted to the external force,so that the pier can form a plastic hinge at the bottom of each step.In this paper,CFRP bars are used to conduct stepped reinforcement of bridge piers,and three reinforcement schemes of double plastic hinge,three plastic hinge and four plastic hinge are designed respectively.Based on the incremental dynamic time-history analysis,the multiplastic hinge bridge pier is compared with the ordinary reinforced concrete pier,and the enhancement effect of the multi-plastic hinge bridge pier design method on the seismic performance of the bridge structure is discussed.The results show that the stepped reinforcement of CFRP bars can cause multi-plastic hinge failures in bridge piers,and the plastic deformation is shared by each plastic hinge.The damage degree of multi-plastic hinge bridge pier develops slowly,and it is difficult to reach the ultimate failure.