Study On Temperature Field And Insulation Measures Of High-speed Railway Subgrade In Seasonal Frozen Soil Region

ABSTRACT:Seasonal frozen soil is distributed widely in the northeast region of china. The prevention measures of frost heave are important to high-speed railway constructed in seasonal frozen soil region due to the strict requirements of subgrade deformation. In order to find out the general frost heave regularity of high-speed railway, the monitoring data of the Harbin-Dalian high-speed railway subgrade were analyzed in this paper. Based on laboratory test and theoretical analysis, the factors which influence frost actions are studied. In addition, the ground temperature monitoring data of a passenger dedicated line in northeast were analyzed to obtain the regularity of temperature distribution and the freezing depth of subgrade.An insulation measure for new high-speed railway subgrade was proposed to prevent the frost heave of subgrade. According to the analysis of the temperature field of subgrade with insulation measures simulated by ANSYS, the composite structure of insulation board-insulation revetment was proved to be effective in preventing track deformation influenced by subgrade frost heave. Reasonable layout width, thickness of insulation board and filling width of insulation revetment were then given in this paper. Finally, the incomplete insulation measure of existing railway subgrade was numerically simulated. Results show that this measure does not have significant effect on insulation. The key to preventing the frost heave of existing high-speed railway subgrade at present is strengthening subgrade waterproof and drainage.