Experimental and numerical simulations on heat-water-mechanics interaction mechanism in a freezing soil

In cold regions, the annual ground freezing is responsible for many distinct and widespread terrain features, such as ice wedges, frost mound and ground ice. In particular, the frost action caused by the soil freezing is a prevailing and heavy damage to engineering structures. The frost heave process of a freezing soil involves complicated coupled heat and water transfers as well as mechanical variation. To explore this multi-physical interaction, first, we built a numerical heat-water-mechanics model based on energy, mass and momentum conservation principles. In this model, several critical important characteristics of the freezing soil are taken into account. Then, we carried out a one-side freezing experiment of silty clay column in an open system with non-pressure water supply. Meanwhile, we used the experiment to simulate the water, temperature and deformation variations of the freezing soil column. The simulated temperatures and displacement well agree with those measured data, which implies the numerical model is valid and can describe the heat-water-mechanics process in the freezing soil. Finally, the heat-water-mechanics interaction mechanism of the freezing soil is explained and analyzed by combining the experimental investigation and numerical simulation. This study is helpful to better understand the interaction between water, temperature, deformation and the frost heave mechanism of the freezing soil. Furthermore, the model and results in the study can serve as references for further investigation, too.