塑性铰区纵向配筋率变化对重力式桥墩抗震性能的影响  

Influence of longitudinal reinforcement ratio change in plastic hinge area on seismic performance of gravity bridge piers

作　　者：鲁锦华 陈兴冲[1] 丁明波[1] 张熙胤[1] 马华军[1] LU Jinhua;CHEN Xingchong;DING Mingbo;ZHANG Xiyin;MA Huajun(College of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学土木工程学院,甘肃兰州730070

出　　处：《铁道科学与工程学报》2020年第9期2288-2295,共8页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(51768036,51968039,51808273)。

摘　　要：针对弯曲破坏型桥墩在地震中仅在墩底塑性铰区内发生严重破坏的情况,提出一种纵向钢筋的布置方法,即仅在墩身底部(2倍塑性铰长度)增加纵向钢筋的数量,其余墩身部位钢筋数量保持不变。设计了5个桥墩,运用ANSYS软件分析了墩身底部配筋率的变化对桥墩抗震性能的影响。研究结果表明:仅提高墩身底部配筋率,可以提高桥墩的承载能力,增强桥墩的耗能能力,增大桥墩的位移延性;与传统相同配筋率的桥墩相比,滞回曲线“捏缩”较为严重;提高低配筋率桥墩底部配筋率,桥墩的抗震性能基本可以达到全截面高配筋率桥墩的抗震性能。In view of the fact that the bending failure pier is only seriously damaged in the plastic hinge area at the bottom of the pier in earthquake,a method for the arrangement of longitudinal steel bars was proposed in this paper.That is,the number of longitudinal steel bars is increased only at the bottom of the pier(2 times the length of plastic hinge),while the number of steel bars in the rest of the pier remains unchanged.Five piers are designed,and the influence of reinforcement ratio change at the bottom of the pier on the seismic performance of piers is analyzed by ANSYS software.The results show that only increasing the longitudinal reinforcement ratio at the bottom of the pier can improve the bearing capacity of the pier,enhance the energy dissipation capacity of the pier and increase the displacement ductility of the pier.Compared with the traditional pier with the same reinforcement ratio in the whole section,the hysteretic curves of two piers have a serious“pinch”effect.By improving the longitudinal reinforcement ratio at the bottom of the pier with low reinforcement ratio,the pier can basically achieve the seismic performance of the pier with high reinforcement ratio in all sections.

关 键 词：重力式桥墩 配筋率 塑性铰区 抗震性能 

分 类 号：U24[交通运输工程—道路与铁道工程]