哈尔滨至大连客运专线是我国在中-深季节冻土地区设计、建造和运营的第一条高速铁路，其独特的工程地质条件以及在低温环境下线路的苛刻要求引发的工程需求对寒区路基的稳定性问题提出了新的严峻挑战。通过在不同冻深区选择典型性路基断面，以用来监测路基的稳定性和冻结特征。并通过对运营后第1个冻融期内的监测数据分析发现，路基的结构型式对寒区高铁路基的冻结特征有着显著的差别性影响和制约作用。结果表明：对比路堑段的中部及其临近路堑进出口处的路堤段，路堤段存续有较长时间和较厚的冻结夹层，其堑-堤地温差值也随着纬度的增加而增加。同时发现在4月份的路基中存在有一定厚度的高温冻结夹层。而同一区域内，路堑的最大冻结深度要较路堤的冻结深度浅20～50 cm，但相反的是，路堑的最大变形却较路堤的要大2～5 mm，这种差值越向北越明显。同时在春融期内，路堑段的冻深变化速率在0上下剧烈波动，此时变形产生了突变式上升，而路堤段的冻深变化速率却在负值区内变化，变形并未发生明显的突变。

The Harbin to Dalian Passenger Dedicated Line (HDPDL) is the first high-speed railway designed, constructed and operated in cold regions in China. The unique engineering geological condition along the HDPDL and the stringent engineering requirements pose severe challenges to the stability of subgrade in cold regions. In order to monitor the stability and freezing characteristics of the subgrade, the typical subgrade sections are selected in different freezing zones. The structure style of subgrade has a remarkable disparate impact and restriction on the freezing characteristics of high-speed railway subgrade in cold areas through analyzing the monitoring data of the first freezing and thawing period after operation. By comparing the middle section of cutting with the embankment near the entrance and exit of cutting, it is found that in this embankment section, there exists thicker frozen interlayers for a long time. The temperature difference between the cutting and the embankment increases with the increase of latitude. It is also found that there is a certain thickness of high-temperature frozen soil in embankment in April every year. In the same region, the maximum freezing depth of embankment is 20 to 50 cm deeper than that of cutting. However, the maximum deformation of cutting is 2 to 5 mm larger than that of embankment, and this difference becomes larger as latitude increases in spring thawing period, the change rate of frozen depth of cutting section fluctuates dramatically around 0; at this moment, the deformation exhibits a rise in mutation manner while the freezing depth change rate of embankment is located in the range of negative, and the obvious mutation in deformation of embankment is not be observed.