Mechanical Properties Of CRTSⅡ Slab Ballastless Track On Long-Span And Long-Unit Continuous Girder Bridge

Abstract:For long-span and long-unit continuous girder bridges on high-speed railway, the temperature span and the braking range are relatively large. CRTSII slab ballastless track is laid continuously on the whole range of bridge. The bridge and the track constitute a mechanical equilibrium system due to the nonlinear constraint between them. Mastering the mechanical properties correctly is one of the keypoints for designing CRTSII slab ballastless track on long-span and long-unit continuous girder bridges.In the paper, combined with the span of (60+3×100+60)m continuous girder bridge-Lian-Shui Long-Span Bridge in ShangHai-KunMing passenger line Chang-Kun interval, the mechanical properties of track system as well as the influence factors were investigated. The main contents of this dissertation are given as follows:(1) Based on the principle of bridge-track interaction, the theoretical formulas for calculating additional longitudinal force were derived. An spatial integer model was established. And the validity of the model in this thesis had been verified through a series of comparative analyses with those in relative codes or papers.(2) The stresses and deformations of CRTSII slab ballastless track on bridge under the load case of girder expanding-contracting, braking-bending and board-breaking were studied. The distribution and transmission law of additional longitudinal force was revealed as well.(3) The influence of several sensitive factors on the longitudinal force was discussed, such as Expanding-Contracting stiffness of bed slab, longitudinal stiffness of CA mortar mixture, friction coefficient of sliding layer and longitudinal stiffness of fixed piers.