Study On Track Block And Limiting Measures Of Low Vibration Track

In order to adapt to the trend of the development of the high speed railway in our country,various types of ballastless track began to widely used in railway line in China.Although ballastless track has many advantages,there are also many problems.And the Interlayer of the road bed plate and the base plate is a relatively weak part of the ballastless track structure.Therefore,this paper relies on the research of LVT structure forms and related technology in heavy haul railway tunnels,embarks from the ballastless track diseases,aims at how to avoid or reduce ballastless track diseases,from two espects of bed board longitudinal block and bed board limit measures to optimize the longitudinal structure of the ballastless track.the main content of the thesis listed as follows :(1)Analysis of the slab longitudinal stressThe diseases of ballastless track is Summarized.the diseases which is caused by longitudinal force are divided into three types: bed board,interlayer damage and limit measures.Analyze the causes of each type of disease.The longitudinal structure force of ballastless track is analyzed and obtain the axial force distribution in bed board and the interlayer shear distribution of interlayer between bed board and base plate under temperature load.Above analysis results served as the basis of the optimization design of the length of unit track concrete layer and the measures of the limit location of unit track concrete layer.(2)The optimization design of the length of unit track concrete layerBased on the analysis results of seamless track the slab longitudinal stress,the displacement and mechanical response of bed board under the temperature load is analyzed.By means of the above analysis,we find that when the unit bed board is 77 m,the temperature stress in the bed board reaches the maximum value.Using finite element analysis software ANSYS to establish the finite element model.The displacement and mechanical response of the unit bed board with different lengths at the same temperature and at the same load of a train is analyzed by using the established model.From the perspective of reducing disease incidence,evaluation the superiority-inferiority of different length unit track concrete layer and then determine the optimal unit bed board length.(3)The optimization design of the measures of the limit location of unit track concrete layerBased on the analysis of ballastless track of interlayer shear to determine the optimization idea of anchor pin of unit ballastless track.According to the action mechanism of anchor pin in bed board and the failure mode of anchor pin limit to determine the finite element simulation method and evaluation index of anchor pin under different working conditions.the finite element model is established with finite element analysis software ANSYS,on the basis of optimization thinking of anchor pin arrangement,comparing limit effect of different anchor pin schemes,determine better anchor pin arrangement scheme.