Study On Temperature Field And Temperature Effect Of CRTSⅡ Plate Ballastless Track-box Girder-pier System Under Natural Temperature

Ballastless tracks are widely used in the construction of high-speed railways in China.The track structure under temperature load is prone to diseases such as arching,damage,cracking of the seam,etc.,and long-term accumulation will affect the service performance of the track structure and endanger driving safety,so it is important to explore the temperature field and its effect on the ballastless track structure system.In this paper,the temperature field and temperature effects,additional unevenness and upper arch stability of the CRTSⅡ.type plate ballastless track-simple support box girder-high pier structure system under the influence of natural environment are explored,which provides reference and guidance suggestions for line design and operation and maintenance.The main research work in this paper is as follows:(1)Based on the relevant theories of meteorology and heat transfer,using ABAKQUS finite element software,considering the influence of parameters such as latitude and longitude,average wind speed,temperature change,structural geometric characteristics and surface occlusion conditions in the area where the structure is located,the CRTSⅡ type plate ballastless track-simple support box girder-bridge pier system temperature field calculation and analysis method is constructed based on meteorological data,and the temperature field characteristics of ballastless track,simple support box girder and bridge pier structure under the action of natural environment are explored.(2)Based on the ABAQUS finite element analysis platform,considering the geometric characteristics and material properties of the structural system,a multi-scale CRTSⅡ type plate ballastless track-simple support box girder-pier structure system temperature effect finite element model is established,and the temperature field calculation results of the structural system based on meteorological data are introduced,and the mechanical behavior analysis of the CRTSⅡ type plate ballastless track-simple support box girder-bridge pier structure system is carried out in the natural environment,and the changes of the geometric shape of the rail are explored under the action of the natural environment.Construct a ballast-free track geometry additional uneven analysis method under the action of natural environment.(3)Based on the interlayer and inter-plate cohesion model and the concrete damage plasticity analysis model,a finite element analysis model of the upper arch of the track structure considering the interface damage between the layers and the plate is established,the joint damage characteristics of the track structure are explored,the arch effect of the end of the track plate is analyzed under the action of natural temperature,the arch formation mechanism on the track plate is summarized,and the influencing factors of the upper arch are analyzed.