鉴于哈尔滨—齐齐哈尔（哈齐）客专路基工后沉降不大于15 mm 的要求，开展了路基现场试验。对路基中的温度、沉降变形、路基冻胀变形及路基本体的含水量变化情况进行监测。结果表明：线路所处地区，11月中旬开始冻结，来年 1月下旬地表附近地温过程线开始上抬；冻结层直到4月中旬才全部处于正温，最大冻深约为2．4 m。经过现场监测，处于深季节冻土区的高铁路基在经历冻融循环后的沉降变形为20 mm 左右。路基表面的最大冻胀量发生在地表温度处于－1～－2℃之间，在此地温值下，路基冻结层范围内易发生水分积聚现象，路堤冻胀较敏感，所以路基填料应严格保持为最优含水量，做好基床表层的防排水措施，避免路基病害的发生。%The settlement of subgrade is not allowed to be more than 15 mm in the Harbin-Qigihar in Pas-senger Dedicated Line.A field test of subgrade was operated in the Passenger Dedicate Line from Harbin to Qiqi-har.The soil temperature, settlement , frost heaving and moisture content were measured.From the results: at the test place, the surface temperature of subgrade was under 0℃ in mid November, and was higher than 0 ℃ in late January.The frozen layer did not thaw until the middle of April.The maximum frozen depth was about 2.4 m.line region.So it is necessary to take insulation protection measures.After observation, the settlement of the subgrade was less than20 mm, which is within the range of the design standard.The maximum frost heaving of the subgrade surface occurred in the surface temperature between -1 ~ -2 ℃.At this temperature, freezing layer is prone to water accumulation within the scope, so the subgrade filling should be strictly maintained with the optimum moisture content, and drainage measures must be taken for shallow foundation to avoid the occur-rence of subgrade disease.
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