Research on the Long-term Deformation of CRTS Ⅲ Slab Ballastless Track-prestressed Concrete Simply Supported Girders
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.
box girderballastless trackshrinkage and creeplong-term deformationlongitudinal stress
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