Analysis of the influence of groundwater salt content on the effect of artificial freezing

Currently, the research on artificial freezing method mainly focuses on the influence of groundwater seepage on freezing effect, while neglecting the salt content. As a result, the mechanism of the effect of the groundwater salt content on freezing effect is not well understood. The salt content will change the thermodynamic properties of groundwater. If the artificial freezing method is applied to temporarily conduct ground improvement in the offshore area and the seabed, high-salt-content groundwater will affect the freezing effect. The aim of this paper is to study the freezing mechanism of high-salt-content groundwater under double pipe freezing by utilizing COMSOL multi-field coupling software based on heat flow coupling model. The influences of freezing temperature field, freezing cycle time, distance of double pipes on freezing effect are especially analyzed. The results show that the freezing range of downstream is greatly affected by the increase of groundwater salt content when the groundwater salt content exceeds 4%. The freezing time of the stage of pre-freezing increases with the increasing salt content of groundwater. While the freezing time of the stage of active freezing time gradually decreases, the salt content of groundwater increases. When the frozen walls completely intersect and freeze, the temperature at the center of the frozen wall increases with the increase of the salt content of groundwater. The freezing effect will be magnified by the increase of frozen pipe distance.