Reserch On Law Of CRTS Ⅱ Slab Ballastless Track Wide-narrow Juncture Deformation Under Temperature Effect

Effect of temperature load is one of important causes of diseases occurring at CRTS II slab ballastless track wide-narrow juncture,so it is of significance for preventing wide-narrow juncture diseases from intensifying and maintenance to deeply conduct the research on law of wide-narrow juncture deformation under hot weather in summer.Based on actual situation on site,the paper set up a monitoring plat form to research law of track plate temperature and wide-narrow juncture deformation under hot weather in summer;select appropriate temperature parameters to establish a wide-narrow juncture deformation prediction model using AI algorithm;Discuss the influence of temperature load on wide-narrow juncture deformation to propose reasonable suggestions on maintenance and repair.Main content and conclusion of the paper are as follows:(1)Law of track plate internal temperature and wide-narrow juncture deformation under hot weather in summer was researched.Using a dedicated passenger railway foundation section in East China as experimental site,an experiment on track plate internal temperature and wide-narrow juncture deformation monitoring was conducted to analyze law of track plate temperature and wide-narrow juncture deformation under hot weather in summer in terms of interlayer overall temperature,vertical temperature and longitudinal temperature.Result shows that wide-narrow juncture deformation is reciprocating pulling-compression change on daily basis,keeping consistent with law of positive-negative alternate change of interlayer temperature variation,vertical temperature gradient,longitudinal temperature difference.(2)AI algorithm based wide-narrow juncture deformation prediction model was established.Through comparison and analysis,use SVM method as the mapping method of track plate temperature and wide-narrow juncture deformation model,focusing on research on selection of the prediction model characteristic parameters to determine using interlayertemperature variation,vertical temperature gradient and longitudinal temperature difference to characterize wide-narrow juncture deformation.Effectiveness of the model was tested through actual data,average daily coverage rate,average daily reliable rate of the result of wide-narrow juncture deformation prediction both are above 95%,meeting requirement of engineering practice.(3)Influence of temperature on wide-narrow juncture deformation was discussed,on the bases suggestion on maintenance and repair is proposed.Comprehensively considering the relation between interlayer temperature variation,vertical temperature gradient and longitudinal temperature difference,influence of three temperature loads on wide-narrow juncture deformation was discussed respectively,all able to establish mapping relation with cubic polynomial,with good fitting effect.The research on deformation of wide-narrow juncture under temperature was focused on,abrupt node was researched and on the basis suggestion of maintenance and repair was proposed.