The combined finite–discrete element method (FDEM) based on the cohesive zone model (the CZM) achieves cracking simulation by inserting cohesive elements between solid elements. In this study, three-point bending fracture tests of frozen soil were simulated by using the FDEM based on the CZM. Firstly, the sensitivity of the cohesive model parameters was analyzed. Secondly, through a series of simulations of the three-point bending test of frozen soil, it was found that the model with reasonable values of the CZM parameters had a good adaptability to the three-point bending cracking test of frozen soil, as the model not only reflects the load-displacement curve, but also has good correspondence with the fracture pattern compared with the test. Finally, the relationship between the CZM parameters and the specimens’ temperature under two loading rates of 1 mm/min and 0.1 mm/min was analyzed, and it was found that the CZM parameters had a good linear relationship with the specimens’ temperature. This paper is expected to provide a new possibility for the numerical simulation of frozen soil cracking.

The water content of the foundation soil will change dynamically as a result of rainfall, snowfall, and ground surface evaporation, leading to a significant change in frost heave properties of the foundation soil in cold regions. One-dimensional freezing tests of the Qinghai-Tibet silty clay with three different initial water contents in an open system were carried out using CCD image acquisition technology and computed tomography (CT) scanning technology in combination with the traditional soil freeze-thaw test system. The heat conduct process, cryostructure formation, frost heave development, unfrozen zone consolidation, ice segregation, water migration, and redistribution during soil freezing are studied comprehensively. The results show that increasing the sample’s initial water content will lead to the increase of frozen depth, ladder-like cryostructures in vertical sections, more structural polygons in horizontal sections, and also more obvious ice lens segregation, unfrozen zone consolidation, and water migration during the freezing of soil samples.