Study on frost heaving force and the propagation of cracks in freezing rocks using the phase field method

In cold regions, the water in rocks expands volumetrically after freezing, leading to the propagation of fractures. In this study, the effective volume expansion coefficient is employed as a substitute for the volume expansion strain after the water in the fracture undergoes freezing and transforms into ice, and the phase field method is used to simulate the propagation of fractures in freezing rocks under various conditions to further explore the law of fracture propagation. The Abaqus software is used to solve the mechanical field control equation and the phase field evolution equation. First, the theoretical calculation of the frost-heaving pressure is compared with that obtained by experimental and numerical calculations. This comparison indicates that the numerical model presented in this study can effectively calculate the frost-heaving pressure during fracture propagation. Subsequently, the propagation of single and double fractures caused by frost heave is simulated based on fracture propagation experiments under frost heave conditions. The simulation results closely resemble the observed morphology of fracture propagation caused by frost heave obtained from the experiments. This confirms the suitability of the proposed model for simulating and predicting the propagation of fractures caused by frost heave. Finally, the influence of volume expansion strain growth path on fracture propagation due to frost heave is discussed. Although the final volume expansion strain value is the same, different growth paths of the volume expansion strain result in different fracture propagation morphologies.