大兴安岭北部霍拉河盆地季节融化层的研究

大兴安岭北部霍拉河盆地季节融化层的特征受气温的控制,并随地面条件、含水量和土质的不同而变化。最大季节融化深度,在土类相同时,裸露的比有植被和雪盖的深0.4—0.5m;土类不同时,卵砾石的最大,碎石亚粘土、亚粘土和草炭亚粘土的分别为卵砾石的0.65、0.5和0.4倍。年平均地温为-0.1℃的季节融化层比年平均地温为0——0.5℃的约提前2—3个月消失。回冻融化层中的地下冰与青藏高原相比,不甚发育,冻土构造主要呈整体状、微层状和裂隙状。

A Study on Seasonally Thawed Layer in the Basin of Huola River in Northern Da Hinggan Ling

In combination with the investigation of engineering geology for Guliang Mine, the investigation and observation on the seasonally thawed layers in the basin of Huola river in the northern Da Hinggan Ling were carried out in the period from 1985 to 1986. It was found that the characteristic of the seasonally thawed layers is controlled by the air temperature and changes with the different ground surface conditions, water content as well as the soil properties. If the soil type is the same, the maximum of the seasonal thaw depth in the uncovered layers is 0.4-0.5 m deeper than that in the layers covered by vegetation and snow. If the soil type is different, the maximum of the seasonal thaw depth in the gravel is the greatest and the maximum of the seasonal thaw depth of the sandy clay with crushed stone, the sandy clay and the peaty clay is 0.65, 0.5 and 0.4 times as deep as that in the gravel respectively. The refreezing speed of the seasonal thaw layer is controlled by the temperature regime of permafrost besides the air temperature. The seasonal thaw layer in the ground with the annually mean ground temperature of ?1 degree centigrade is disapearred about two or three months earlier than that in the ground with the annually mean ground temperature from 0 to-0.5 of degree centigrade. The develop of ground ice in the refrozen thaw layers is not as well as on the Qinghai-Xizang (Tibet) Plateau. The texture of frozen ground in the refrozen thaw layers is mainly in the massive, micro-layered and crevice shapes.