Reasonable Pier Stiffness Of CRTS Ⅱ Ballastless Track On Bridge

CRTS II ballastless track on bridge is widely used as track structure nowadays. The interaction between railway-bridge-pier system is complex. The longitudinal pier stiffness remarkably affects the forces and deformations of the track. There is a need to clarify this kind of influencer. Based on the analysis on the development and characteristics of the ballastless track home and abroad, and on the model for the CRTS II ballastless track, this article probed new control standards of the pier stiffness from the perspective of the stress and deformation of track. Having studied related codes worldwide, three control standards are raised up as below:the first, under the load of braking force and temperature variance, additional longitudinal force in the rail be no more than 472.40 kN; the second is:the force impact on the consolidation between base plate and bridge be less than 8408.40kN; the third: relative displacement between rail and bridge caused by braking force and temperature be less than 1.00 mm.Based on finite element method, using secondary development of software BCWS based on the common finite element analysis software ANSYS, for the commonly used simple beam and continuous beam, established the model for analyze the influence of pier stiffness on the track, and calculated, analyzed the impact of pier stiffness on the longitudinal force in the rail and relative displacement between rail and bridge. Different number of spans and span lengths were taking into account.The results show that longitudinal stiffness of the. pier significantly impacts the additional longitudinal forces in rail and the relative displacement between rail and bridge, and as bridge span increases, this kind of influence becomes more significant. This amplification effect of span length is greater than number of span.By comparison, from the perspective of rail security and stability, a variety of situations for suitable pier stiffness was analyzed. And combined with economic factors, two continuous beam forms are recommanded to use on long bridges:one is a continuous beam with 3-5 spans by 32 m and the other is 3 spans by 48 m. Further proposal was raised to concise the influence of the rail cushion on the relative displacement between rail and bridge.