Sublimation of Pore Ice in Frozen Silt

Abstract

Sublimation of pore ice in frozen silt when excavating in permafrost is a serious engineering health and safety problem due to the release of resulting dust. As part of a continuing effort to develop guidelines for mining and construction in cold weather environment, a study of the relationship between sublimation of fine‐grained frozen soil and various factors such as the water content of the silt, the relative humidity, and the ambient temperature of air has been investigated. Of these factors, ambient air temperature is found to be most important. The relationships of the variables correlate to a power model, which describes a gradual decrease of the sublimation rate as the heat‐and‐mass transformation proceeds. A graphic solution is presented from which an estimate of the amount of ice susceptible to sublimation can be made based upon temperature, water content, relative humidity, and time.