On the influence of unfrozen water content curve models on the accuracy of temperature field prediction in artificial ground freezing

Abstract

Three different models of the content of unfrozen water used in the description of freezing of water-saturated rock masses are considered in the work: the power-law model; the van Genuchten-Mualem model; and the Kozlovsky model. An analysis of the applicability of these models for interpreting laboratory measurement data from sand and clay samples was conducted. It was established that all models describe the experimental data with acceptable accuracy; however, the van Genuchten-Mualem model generally yields the best results, particularly for clay. The validity of applying this model under field conditions was confirmed by mathematical simulation of artificial ground freezing in the shaft of a potash mine. It was found that, over extended periods (six months or more), the discrepancies between the calculated and experimental temperatures in monitoring boreholes remain negligible. This justifies recommending the van Genuchten-Mualem model for simulating artificial freezing of various rock types in monitoring tasks and for designing frozen wall.