Research On The Longitudinal Horizontal Stiffness Limited Value Of Common Continuous Grider Bridge Pier's Top

The continuous welded rail is a great renovation on track structure,and it's one of the main symbols of railway modernization.The interaction additional longitudinal force between continuous welded rail and bridge is an important force for bridge.The longitudinal horizontal stiffness of pier's top is a critical parameter in the design of the bridge and continuous welded rail.The distribution of longitudinal force between the rail and the pier as well as the displacement of girder and rail,to a great extent, depends on the longitudinal horizontal stiffness of pier's top.Taking the common(32+48+32)m,(40+64+40)m,and(48+80+48)m continuous girder bridge as research objects,the limited values of longitudinal horizontal stiffness of pier's top are investigated.As for the additional longitudinal force of continuous welded rail on bridge,the primary design differences at present are systematically surveyed and summarized according to design conception,parameter selection and calculation model.Subsequently,a rail bridge pier foundation interaction analysis model of continuous welded rail on bridge is established.Correspondingly a program named ALFCWR(Additional Longitudinal Forces of Continuous Welded Rail)is compiled basing on re-development of large general finite element analysis software ANSYS by using of its parameter design language,that is APDL.The reliability of ALFCWR is proved by comparatively analyzing its calculation results to BCWR's,a program widely used by large-scale survey and design institute of domestic.Take the three common continuous girder bridges as research objects, this thesis analyses how the longitudinal horizontal stiffness of pier's top impacts the additional longitudinal force of rail and pier,as well as the displacement of girder.The limited values of longitudinal horizontal stiffness of pier's top according to the three continuous girder bridges are given,which can be served as reference for engineering.Referring to German's bridge design code DS804(B6 page),the additional longitudinal forces of continuous welded rail on continuous girder bridge caused by temperature difference of piers are computed.The influencing factors of additional longitudinal forces of rail,such as pier height and it's longitudinal horizontal stiffness,span of bridge,position of fixed bearing as well as the number of continuous beams are analyzed, some useful conclusions are drawn.