高强预应力体系下桥梁中部齿块锚固区性能  

Performance of Anchor Zone of Middle Tooth Block of Bridge Under High⁃strength Prestressed System

作　　者：陈浩瑞 苏永华 石龙 李旺旺 胡所亭 CHEN Haorui;SU Yonghua;SHI Long;LI Wangwang;HU Suoting(Railway Engineering Research Institute,CARS,Beijing 100081,China;CARS,Beijing 100081,China)

机构地区：[1]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081 [2]中国铁道科学研究院集团有限公司,北京100081

出　　处：《铁道建筑》2024年第5期7-12,共6页Railway Engineering

基　　金：中国国家铁路集团有限公司科技研究开发计划课题(K2021G019);中国铁道科学研究院集团有限公司基金课题(2021YJ201)。

摘　　要：近年来预应力技术水平不断提升,2 200 MPa级高强度的预应力体系开始应用于铁路预应力混凝土桥梁工程建造,对于梁体锚固区特别是广泛应用在连续梁结构的中部齿块锚固区的受力提出了更高要求。基于既有1 860 MPa预应力等级的中部齿块锚固区设计,提出适应2 200 MPa预应力等级的设计方案,建立典型中部齿块锚固区有限元模型,对比分析了预应力强度等级对中部齿块锚固区受力和变形各项性能的影响,并完成了足尺试验验证。研究结果表明:预应力等级从1 860 MPa提升至2 200 MPa时,采用中部齿块锚固区尺寸不变、锚垫板尺寸和普通钢筋配筋适当增加的设计方案,可保证混凝土拉压应力、普通钢筋应力、锚固区变形基本一致,且均满足相关规范要求。In recent years,with the continuous improvement of prestressing technology,2200 MPa high-strength prestressing system was applied to the construction of railway prestressed concrete bridges.This had higher requirements on the strength of the beam anchorage zone,especially the middle tooth anchorage zone which was widely used in continuous beam structures.In this paper,based on the design of the anchorage zone of the middle tooth block with the existing 1860 MPa prestress grade,a design scheme adapted to the 2200 MPa prestress grade was proposed.A finite element model of the typical middle tooth block anchorage zone was established,and the influence of the prestress strength grade on the mechanical and deformation properties of the middle tooth block anchorage zone was compared and analyzed.A full-scale test was conducted to verify the design.The research results shows that when the prestress level is increased from 1860 MPa to 2200 MPa,the design scheme,in which the size of the anchorage zone of the central block remains unchanged and the size of the anchor plate and the ordinary reinforcement are appropriately increased,can ensure that the stress of the concrete,the stress of the ordinary reinforcement and the deformation of the anchorage zone are basically the same,and all meet the relevant specifications.

关 键 词：铁路桥梁 中部齿块 理论分析 预应力 锚固区 局部应力 

分 类 号：U448.35[建筑科学—桥梁与隧道工程]