CRTS Ⅲ型板式无砟轨道-PC简支梁长期变形研究
Research on the Long-term Deformation of CRTS Ⅲ Slab Ballastless Track-prestressed Concrete Simply Supported Girders
郑志辉 1刘磊 2刘鹏 3余志武3
作者信息
- 1. 浙大宁波理工学院,宁波 315100
- 2. 伊犁师范大学,伊宁 835000
- 3. 中南大学,长沙 410075
- 折叠
摘要
研究目的:以CRTS Ⅲ型板式无砟轨道-PC简支梁体系(梁-轨体系)为研究对象,开展混凝土收缩徐变作用下梁-轨体系的长期变形研究,分析底座板、自密实混凝土及扣件长期受力特点.研究结论:(1)相较于单独箱梁(将无砟轨道转化为均布荷载作用),梁-轨体系下箱梁徐变上拱反而有所增大;(2)箱梁长期变形导致无砟轨道上拱,引起钢轨与轨道板、底座板与自密实混凝土部分区域产生竖向变形差,进而导致底座板和自密实混凝土脱空;(3)底座板和自密实混凝土的纵向拉应力、扣件竖向附加力均较小,但梁端处部分扣件纵向力达到极限值;(4)小阻力扣件能够有效削弱梁轨相互作用,减小箱梁长期变形引起的无砟轨道纵向应力和扣件竖向力;(5)本文研究成果揭示了梁-轨体系长期变形协同工作机理,可为CRTS Ⅲ型板式无砟轨道结构运营期间的维养提供一定的理论依据.
Abstract
Research purposes:Taking the CRTS Ⅲ slab ballastless track-prestressed concrete simply supported girders(the girder-rail system)as the research object,the long-term deformation of the girder-rail system is studied under the action of concrete shrinkage and creep,the long-term stress characteristics of the base plate and the self-compacting concrete,as well as the vertical and longitudinal forces of fasteners are analysed.Research conclusions:(1)Compared with the single box girder(the uniform load converted from the ballastless track system is applied on),the creep camber of the box girder of the girder-rail system is increased.(2)The long-term deformation of the box girder leads to a camber of the ballastless track and causes vertical deformation differences between the rail and the slab track,and between the base plate and the self-compacting concrete,thus leading to voids between the base plate and the self-compacting concrete.(3)The longitudinal tensile stress of the base plate and the self-compacting concrete,and the vertical additional force of the fastener are small,but the longitudinal additional force of the fastener reaches the limit value within a certain range at the girder end.(4)The small resistance fastener can effectively weaken the girder-rail interaction and reduce the longitudinal stress of the ballastless track and the vertical additional force of the fastener caused by the long-term deformation of the box girder.(5)The research in this paper reveals the long-term deformation coordination mechanism of the girder-rail system,which can provide a theoretical basis for the maintenance of CRTS Ⅲslab ballastless track structure during service.
关键词
箱梁/无砟轨道/收缩徐变/长期变形/纵向应力Key words
box girder/ballastless track/shrinkage and creep/long-term deformation/longitudinal stress引用本文复制引用
基金项目
国家自然科学基金(52178182)
国家自然科学基金(52108262)
国家自然科学基金(U1934217)
湖南省自然科学基金-杰出青年基金(2022JJ10075)
出版年
2024
NETL
NSTL
万方数据