Analysis on Difference of Ground Temperature and Deformation Between Southern and Northern Sides of High-speed Railway Embankment in Cold Regions

Based on in-situ embankment ground temperature and deformation monitoring data of Taikang test section of Harbin-Qiqihar Railway Passenger Dedicated Line in cold region, the difference of ground temperature and deformation between the southern and northern slopes of the embankment was studied. The results showed that: (1) The maximum frozen depth of the right shoulder and right toes of slope was greater than that of the left shoulder and left toes of the slope. (2) In most of the time, the ground temperature of the left side was higher than the right side. At the same time, the temperature difference of the corresponding depth of the shallow layer of the southern slope and the northern slope of the embankment would not disappear completely with the passage of time and the increase of buried depth, but the temperature difference between the southern and northern slopes was gradually reduced year by year and tended to be constant. The temperature fluctuation amplitude decreased gradually with the increase of depth. (3) The starting time of frost heaving of the southern and the northern sides of the surface of the embankment was the same, but the starting time of the thawing settlement of the northern side was one month later than the southern side. When the ground temperature of the shallow layer of the embankment was in the range of -2~0℃ and the top and bottom of the frozen layer began to melt simultaneously, significant embankment frost heaving occurred. The frost heave that occurred at this time accounted for approximately 40% of the total amount of frost heaving. (4) In the early stage of the completion of embankment construction, the cumulative settlement of the shallow layer and the substrate in the southern side was greater than the northern side. The closer to the embankment slope toes, the greater the settlement difference was between the southern and the northern sides, with the difference decreasing year by year. the cumulative settlement of the measuring points tends to be stable. This indicated that even though using thermal insulation to protect frozen soil subgrade, the influence of external temperature still existed in the difference between the southern and the northern slopes of the subgrade after multiple cycles of freezing and thawing, but the difference gradually remained stable with time. Therefore, some measures should be taken to reduce the ground temperature of the southern slope, to maintain the overall stability of the embankment. © 2017, Editorial Office of Journal of the China Railway Society. All right reserved.