Research On Damage Characteristics Of CRTSⅡ Slab Ballastless Track End Stab Zone Under Temperature Load

With the development of China’s economy,high-speed railway has become an indispensable part of people’s life.Ballastless track is affected by many factors such as temperature load,train load and so on in the long-term service process,which will produce various forms of diseases.The investigation shows that during the operation of CRTSII slab ballastless track,there are many kinds of diseases in the end stab zone,such as the damage of wide and narrow joints,the fracture of track slab,the opening of interlayer interface and so on,which seriously affect the traffic safety.Therefore,it is of great significance to explore the damage development mechanism and law of the end stab zone of ballastless track.In this paper,according to the three disease modes of track slab fracture,mortar layer damage and interface crack between bearing layer and transition plate layer,ABAQUS finite element software is used to establish the separated nonlinear analysis model of ballastless track in end stab zone.The damage characteristics of ballastless track system under different temperature loads are analyzed.Based on the structural reliability theory,the damage parts are randomly set to study the reliability of track structure under random damage.The main research contents are as follows:(1)Based on the investigation of the operation line of a station,the main forms and characteristics of the diseases in the end stab zone of CRTSⅡ slab ballastless track are summarized.According to the data,combined with the main characteristics of the structural diseases in the end thorn area,the causes of the disease were analyzed.(2)Combined with the structural characteristics of ballastless track in the end stab zone,the secondary development of ABAQUS is carried out with Python programming software,and the idea of parametric modeling is adopted to establish the separated nonlinear model of ballastless track in lower stab zone under damage conditions.The model uses linear and nonlinear spring elements to simulate the interaction between components and cracks in the components.Meanwhile,due to the python parametric modeling,the internal parameters can be selected randomly to simulate the random damage.(3)Based on the finite element model of ballastless track in the end stab zone,the longitudinal mechanical properties and damage characteristics of track structure in the lower stab zone under different temperature loads are analyzed under the conditions of track slab fracture,mortar layer damage and base plate cracking.At the same time,according to the track slab fracture condition,the structural function function is constructed based on the reliability theory,and the disease is randomly placed to analyze the evolution law and reliability of structural disease in the end stab area of ballastless track.(4)The method of combining manual detection and video monitoring was used to monitor the disease location in the terminal prick area for a long time,and the monitoring data were analyzed.By comparing the monitoring data,the reliability of the monitoring system is proved.