Multi-Physics Modeling of Phase Field Fracture in Fluid-Saturated Mining Environments during Excavation.

This study presents a comprehensive numerical framework for simulating the evolution of fractures in mining sites characterized by fluid-saturated media during excavation. The proposed model integrates phase field fracture mechanics with a coupled solution approach, employing the finite volume method to solve fluid flow equations and the finite element method for geomechanical analysis. The complex interaction between fluid flow and geomechanics is crucial in understanding and predicting fracture propagation in mining environments. The phase field approach allows for a continuous representation of fractures, capturing their initiation, propagation, and coalescence throughout the excavation process. The model incorporates the influence of fluid saturation on fracture behaviour, providing a more realistic representation of the dynamic interplay between the geological medium and the excavated space. The fluid flow equations are discretized using the finite volume method, considering the poroelastic nature of the rock mass. This approach enables the accurate simulation of fluid movement within the saturated medium, considering the changes induced by excavation activities. Simultaneously, the geomechanics equation is solved using the finite element method, accounting for the stress distribution and strain evolution in response to excavation-induced changes. To validate the efficacy of our FEM code, the model is initially subjected to a single fracture scenario, treated as a notch, and benchmarked against published experimental and numerical results for an elastic medium subjected to compressive loads. The successful validation underscores the robustness of our approach in capturing mixed-mode fracturing phenomena in mining environments. The coupling of fluid flow and geomechanics allows for a thorough investigation of the impact of excavation on fracture initiation and propagation in mining environments. The proposed model provides valuable insights into the complex mechanics of fracture evolution in fluid-saturated mining sites, aiding in the development of strategies for optimizing excavation processes and ensuring the safety and stability of mining operations. The integration of finite volume and finite element methods enhances the accuracy and efficiency of the simulation, making the model a powerful tool for researchers and practitioners in the field of mining engineering.