地下冰是冻土的重要组成部份,它的存在对工程影响极大。我们于一九七七年四月至九月对青藏线风火山地区二十余公里地段内地下冰的一般特征,冰结构及物理化学性质等进行了较为全面的研究。同时通过对富含地下冰地段内轻、重矿物的分析和易溶盐的测定,得到了一些初步的认识。 Underground ice is an important part of frozen soil, its existence has a great impact on the project. From April to September 1977, we conducted a comprehensive study of the general characteristics, ice structure and physico-chemical properties of subterranean ice in more than 20 kilometers of the Qinghai-Tibet Railway’s Fenghuoshan area. At the same time, some preliminary understandings have been obtained through the analysis of light and heavy minerals in the underground ice-rich sections and the determination of soluble salts.