A Thermo‐Hydro‐Mechanical‐Phase Transition Coupled Field‐Enriched Finite Element Method for Simulating Water‐Ice Phase Transition Induced Crack Propagation in Rock Masses
Xiaoping Zhou, Kunlin Liu, Han Li
Abstract
ABSTRACT In this paper, a THM coupled field‐enriched finite element method is proposed to simulate water‐ice phase transition induced crack propagation in fractured rock masses. The governing equations of temperature, phase, fluid flow and deformation are based on the thermo‐poroelastic theory and Allen–Chan equation, in which the relationships among these physical fields are fully coupled. Two field variables are introduced to characterize the crack properties, and to describe water‐ice phase transition. The coupled multiphysics governing equations are solved by the staggered Newton‐Raphson iterative algorithm. The accuracy of the proposed method is carefully validated by homogeneous freezing of intact media, unidirectional freezing of cracking media, freezing and deformation of intact sandstone in the aspects of experimental results and previous numerical solutions. Additionally, the performance of the proposed method for simulating water‐ice phase transition induced crack propagation in fractured rock masses is validated and compared with the experimental results and FDEM results. Finally, the application of the proposed method in frost induced cracking of slope in shallow cold regions has been realized. The numerical results have shown that the proposed method is able to accurately simulate water‐ice phase transition induced crack propagation in rock masses, and to simulate evolution of the water‐ice phase transition interface.