雅库特铁路路堤富冰冻土的温度研究(英文)

Temperature study of railway embankments on ice-rich permafrost in Yakutia

由Tommot到Niznhy Bestyakh铁路建设和运行的主要难题是横贯高含冰量冻土区域。自2007年以来,监测研究已经由麦尔尼科夫冻土研究所在该铁路试验段进行。其中一个监测计划的主要目标是评估不同设计的堤防地面热状况。观测巷道中使用高、低和零堤防热管及保温绝缘材料。实地研究表明,每年高路堤的散热效果要小于低路堤。阴影边坡下方的土壤趋于低温,而更多的边坡下方的多年冻土上限是由于地表水的增温效应降低所导致。冬季冻土路堤材料导致其冻胀,其上升的速度使其形成更高的堤防。夏季,零堤的位置处于切除活跃层会导致常年解冻区域的发展,有着较厚的填充和更深层次季节性融化。热虹吸和绝缘材料使得上坡护堤和下坡护堤产生轻微冷却效果。悬雪棚并未证明可以有效地降低地面温度。建议采取额外措施,以降低地面温度,减少巷道的季节性融化。

The Tommot to Niznhy Bestyakh railway traverses an area of ice-rich permafrost which pres-ents major difficulties for its construction and operation .Since 2007 , monitoring studies have been per-formed by the Melnikov Permafrost Institute in this test section of the railway .One of the main objectives of the monitoring program is to assess the ground thermal regime beneath embankments of different de -signs.Observations are conducted in the roadway with high , low and zero embankments incorporating thermosyphons and insulation materials .Field studies have demonstrated that the annual cooling effect of higher embankments is less than that of lower embankments .Soils beneath the shaded sideslope tend to cool, while beneath the more exposed side slopes the permafrost table is lowered due to the warming effect of surface water .Winter placement of embankment material results in rising of the permafrost table , with the rate of rise being greater for higher embankments .The placement of a zero embankment in sum-mer with removal of the active layer results in the development of a perennial thaw bulb .The thicker the fill, the deeper is seasonal thaw .The cooling effect of thermosyphons and Penoplex insulation is strong beneath the downhill berms and minor beneath the uphill berms .Overhanging snow sheds have not proved to be beneficial in reducing ground temperatures .Additional measures are recommended to lower ground temperatures and reduce seasonal thaw in the roadway .