Modeling temperature change and water migration of unsaturated soils under seasonal freezing-thawing conditions

Frost heave and thawing settlements of seasonally frozen soil have a direct impact on the stability of engineered ground in cold regions. On the basis of the theory of seepage and heat conduction of unsaturated soil, a coupled thermal-hydro-mechanical numerical model of frozen soil was established. The alignment of experimental testing outcomes with numerical simulation results confirms the model's precision. The research findings indicate that the duration of freezing emerges as the primary factor influencing seasonal frost heave, with the soil frost heave rate ranging from approximately 1.5% to 3.3%. Within a period of 45 to 60 days following the conclusion of the freezing period, the ground height will return to its pre-freezing level. Construction of foundations in Daqing between late May and mid-October can help mitigate the damage caused by frozen soil. The variation laws of hydrothermal migration and frost heave in seasonally frozen soil have been summarized. The obtained results offer guidance for predicting soil frost heave and designing frost-heaving-sensitive engineering projects in cold regions.