Abstract：The structure of test embankment and monitoring system of the insulation embankment test section in Beiluhe site of Qinghai-Tibet Railway are described. Based on the observed data of the first round year from building of the embankment，the dynamic process of the underlying permafrost，heat budget passing of insulation layer and temperature accumulation at both surfaces of insulation layer are preliminarily analyzed. Results indicate that the insulation embankment，to some extent，is of the function of protecting permafrost. A durative zero temperature zone may exist between the original ground surface and permafrost table. The heat entering insulation layer presents a serious asymmetry. The sunshiny side of the embankment absorbs much more heat than that of the shade side.
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2003, Vol. 22 
