Research On Effect Of CA Mortar Layer Damage On The Mechanical Properties Of Slab Ballastless Track

CA mortar layer is an important part of CRTS II slab ballastless track structure, track as the adjustment layer of plate structure and the supporting layer, mainly supports the track plate structure, buffer high-speed train load and reduce the vibration effect. However, with the increase of the service time, CA mortar layer occured damage in different degrees.This paper studies the effects of the damage of CA mortar layer to the static and dynamic of the track structure system. First, this paper summarized the current research situation of the damage of CA mortar layer, introduced the main forms and reasons of the damage of CA mortar layer; Then created 3D solid model of ballast track—subgrade coupling which based the finite element theory, in the same time test and verified the model; After that simulated the damage by the deactivation elements and changing of contact type, then created the 3D solid model of ballastless track —subgrade coupling of CA mortar layer with damage and ballastless track of CA mortar layer with damage, respectively made the static analysis and the influence on the model of track structure vibration; Finally, on this basis made analysis of the dynamic response.Research shows that:(1) Static analysis, the static effect of CA mortar layer damage on the track structure is caused by stress redistribution. It led to the track plate tensile stress and deformation increase. If the length of the off block of CA mortar layer exceeds 0.65 m, the stress increases significantly. In view of this situation, the paper suggests immediately to repair it.(2) Vibration modal analysis, the mortar void and off block will change the natural frequency of vibration of track structure. The mortar void and off block will change the natural frequency of vibration of track structure, that make it easy to produce resonance with the bridge structure.(3) Dynamic response analysis, the separation will make the structure vibration acceleration doubled, and accelerate fatigue of track structure damage. Relatively speaking, the collapse of mortar layer, which the width is 5 cm, has little influence on the track structure system.