Study On The Influence For The CRTSI Slab Track Induced By Subgrad Frost Heaving

Railway subgrade frost heaving has a great impact on the speed-increase of existing railway lines. Differential subgrade frost heaving of high-speed railway can cause unreasonable deformation of line arch and cause safety hazard of railway operation. Research is still not complete about the influence of frost heaving on high-speed railway ballastless track structure in current information.Harbin-Dalian high-speed railway lines are more typical of cold regions railroad track, which line type is CRTS I slab track structure. Combined with the subgrade frost heaving characteristics of Harbin-Dalian high-speed railway, the article analyse theoretically the effect of subgrade frost heaving on high-speed rail slab track structure based on the analysis and collationg of domestic and international rail frost heaving information. The main contents are as follows:(1) Deformation type of railway subgrade and the characteristics of subgrade frost heaving are analyzed, which acquire the simulated curves of railway subgrade frost heaving and the loading method when frost heaving deformation acts on the track structure.(2) Finite element method and software are used to study CRTS I Slab track, set up the calculation model of ballastless subgrade frost affect, and calculate frost heave peak at slab middle and slab edge in consideration of the low temperature in winter and the train load conditions. The results show that the frost heaving displacement at slab middle is smaller than the slab edge, but track stress is bigger.(3) Track structure deformation and stress are calculated under conditions of subgrade frost heaving which has different heaving peaks and wavelengths; the calculation results of different factors, such as track structure displacement, interlayer seam, longitudinal deformation range and the first main stress factor are analyzed; the results shows that maximum stress and displacement of track are mainly affected by frost peak and the trends of track longitudinal stress and displacement are mainly affected by frost wavelength; track structure frost heaving limits are put forward when the track structure are damaged according to the calculation results.