Study on mapping relationship between bridge vertical deformation and track geometry of high-speed railway

In view of a 32 m simply-supported beam bridge and CRTSI slab ballastless track structure commonly used in high-speed railway, the stress of the interlayer structure of a ballastless track is analyzed. Then a mapping analytical model of the bridge vertical deformation and the track geometry is established. Through the comparison between the results from the mapping analytical model and finite element model and indoor experimental tests for the rail deformation and fastener force under different bridge vertical deformation modes, the accuracy and effectiveness of the mapping analytical model are verified. The concept of a rail-deformation-elongation coefficient is proposed to describe the relationship between the length of a rail and its beam deformation area andthe key parameters affecting rail deformation.Besides,by studying the influence of key parameters on rail deformation, the measures for controlling rail deformation are put forward. The results show that the general mapping analytical model can be used to solve the rail deformation of CRTSI slab-ballastless-track structure caused by bridge vertical deformation. When the vertical beam-fault occurs, the maximum deformation value of the rail depends on the vertical-beam-faultamplitude. The rail will appear 'up-warping' on the vertical deformation boundary. Besides, using the fastener with smaller stiffness can make the rail-deformation curve gentler. © 2019, Engineering Mechanics Press. All right reserved.