Evolution Laws for Frozen Wall Formation under Conditions of Sudden Seepage

Sudden seepage is a special working condition affecting artificial ground freezing (AGF) in many projects which results in significant differences within the temperature field. In order to study the characteristics of frozen walls influenced by water flow, a series of model tests were carried out at different seepage velocities. The model test results show that a frozen wall will change from symmetrical to eccentric as the cooling energy absorption of the soil and the brine return temperature increase. In model tests, when the seepage velocity was 0∼30 m/d, the frozen wall was partially destroyed. When the seepage velocity exceeded 30 m/d, the frozen wall was completely destroyed. This study examines the expansion rate of the upstream and downstream freezing fronts, and the distribution law of the freezing temperature field, the average temperature change under different seepage speeds, and the bearing capacity of the freezing wall are analyzed. Research on these factors suggests that a frozen wall has a certain level of resistance to sudden seepage. When the flow velocity is small, the freezing effect will be strengthened. With an increase in the flow velocity, the freezing effect will gradually weaken. Based on these conclusions, the current study points out targeted solutions that should be adopted in cases of sudden seepage in a project.