Study On Mechanical Characteristics Of CRTSâ…¢ Slab Ballastless Track In Cold Region

ABSTRACT:The CRTS III ballastless track is a new type ballastless track structure system that has China’s independent intellectual property rights and is one of the most popular track structure systems. The Panjin-Yingkou passenger dedicated line, launched operations on September2012, is the first passenger dedicated line that using CRTSIII slab ballastless track in the cold region. Because of the special climatic conditions in cold region, we must face the problems of CRTS III type ballastless track caused by low temperature, frost-heave and thaw-settlement. Therefore, it is necessary to study the characteristics of CRTSIII slab ballastless track structure in the cold region.In this paper, with the background of Panjin-Yingkou passenger dedicated line, we use the software ABAQUS to establish the ballastless slab track model on soil subgrade and do the following researches on the mechanical characteristics of the CRTSIII slab ballastless track.(1) Considering the low temperature and the wide range of temperature, using the finite element software ABAQUS to establish the analysis model to study the displacement and stress distribution of the track structure under different types of temperature load. On this basis, study the influence of the reinforcement on ballastless track structure temperature stress. The results show that:the stress and deformation of the track structure under the temperature load is very large, especially the stress state of the slab, so we suggested that the CRTSIII slab track should using double reinforcement and increase the reinforcement in the middle of the slab.(2) Establish the track structure static analysis model and vehicle-track-subgrade coupling dynamic analysis model. To study the mechanical characteristic of the track structure under train load and temperature load when the SCC is damaged and put forward the limit value of the damage. In addition, study the impacts of SCC damage on the dynamic response of vehicle and track structure. The results show that:the limit value of the SCC damage based on track structure strength is reasonable.(3) Establish the vehicle-track-subgrade coupling dynamic analysis mode that can simulate the differential deformation of frost-heave and thaw-settlement. To study the mechanical characteristic of the track structure under differential deformation of frost-heave and thaw-settlement. In addition, verify whether it is effective by reducing the train speed to weaken the dynamic response caused by frost-heave and thaw-settlement. The results show that:the subgrade frost-heave and thaw-settlement have great influence on the dynamic response of vehicle and track structure, especially increased the dynamic stress of track structure; reducing the speed can play a role in reducing the dynamic response, but with the vehicle speed continues to decrease, the reduction of the dynamic response become slowly, therefore, only by reducing the speed to reduce the dynamic response is not feasible.