| Abstract:CRTS II slab ballastless track was widely used in China’s high speed railway system. CRTS II was longitudinally continuous and anchorage systems were installed in the end on long bridges. The track structure didn’t produce longitudinal deformation because of the longitudinal constraint when temperature changed. But on the other hand, it would endure great axial forces and bending moment. This thesis mainly researched the stability of CRTS II on32m simply supported bridges. The main contents included:(1) Assumed that the bond between layers were very strong and wouldn’t produce relative slip. Elastic conversion method, split rigidity method and coupling stiffness method which based on the first order shear deformation theory were applied to deduct the track structure’s elastic buckling stability formulas. Finite element model(FEM) calculation results were consistent with theoretical calculation results.(2) Based on ANSYS, an entity CRTS Ⅱ finite element model(FEM) was established, in the model, solid finite elements were used to simulate track plate, CA mortar and bed plate; contact elements were applied to simulate the contact relationship between adjacent layers; compression bar element were used to simulate the bridges; Nonlinear spring element were applied to simulate the pigeonhole type lateral blocks.(3) Elastic stability of CRTS Ⅱ under various end boundary conditions and different layer relations including bonding, contact and free relations were explored; the influence of CA mortar parameter, span numbers and pier stiffness were analyzed.(4) The critical temperature of instability were calculated by considering track system, interface contact and lateral blocks’nonlinear characteristic; the mortar joints occurring conditions and reasons of the rail plate arch were analyzed by considering the effects of temperature gradient and track plate seam defect. Some technical measures on how to prevent the upwarping of track plate were carried out. |
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