Research On Testing And Evaluation Technology Of Freezing Damage Of Ballasted Track Subgrade In Cold Region

As the ballast track high-speed rails have been operatied,there is a certain degree of frost damage problem.The problem of freezing of the railway subgrade in cold regions has always troubled the operation and maintenance of railways and threated the safety of railways in winter.A lot of manpower,materials and financial resources have been wasted for maintenance and remediation every year.Therefore,how to prevent subgrade from freezing damage and assess it is a problem that we need to seriously treat.To deal with the subgrade frost damage,it depends on the efficient detection and scientific assessment.Fixed,regular,fixed-point inspection system is applied on subgrade frost damage detection,combined with experiences in previous years,can prejudge some latent frozen damage.But the frost damage sometimes occurs randomly and has a hysteresis,and the frost position should be determined more accurately.A single factor is taken into consideration in the current assessment of frost damage.But the climates,subgrade structure,filling,hydrogeology,drainage system,past medical history and test monitoring results also have their effects on the frost damage and should be considered,too.A comprehensive scientific evaluation of the forecast system should be proposed to lay a good foundation for the maintenance of frost damage.The main conclusions in this paper are as follows:Firstly,for the Bin-Sui line and Bin zhou line,ground penetrating radar was applied to detect the water content of roadbed and so on.According to the railway detection technology,detecting the railway irregularities,and using the high-lift technology to rectify the line irregular were conducted.The relationship between roadbed water content and high lift data was studied,and analyzation on the correlation between track detection and radar detection was conducted,in order to prevent frost damage before winter.Secondly,based on the test results,a systematic,scientific,simple and efficient assessment system which takes climatic conditions,filler conditions,hydrogeology and some other factors into account was built to evaluate the frost damage.