FracLab: A robust 3D DFN generator for coupled stress-flow-transport modeling of complex fractured media

We present FracLab, a new 3D discrete fracture network (DFN) generator, along with a workflow for coupled stress-flow-transport simulations in 3D complex fractured media. FracLab integrates optimized geometry trimming and enhanced rejection criteria to generate high-quality 3D DFNs, enabling robust mesh generation for both fractures and rock matrix. By optimizing the full-domain geometry, FracLab regulates the minimum element size and reduces the number of domain mesh elements while improving mesh quality. This facilitates efficient 3D multiphysics simulations, which can effectively capture nonlinear geomechanical deformations, local stress variations, and fracture–matrix interactions, as well as stress-dependent fluid flow and solute transport in densely fractured media. We present numerical examples to demonstrate the model’s capability in resolving localized shear slip and aperture dilatancy within a 3D fracture network under high differential stress, leading to stress-induced aperture heterogeneity, strong flow channeling, and anomalous transport behaviors. This study showcases FracLab’s capabilities in enabling high-fidelity 3D multiphysics modeling of complex fractured media, offering an efficient and practical solution for challenging geotechnical and geological engineering problems.