This paper presents the development and verification of a new, fully-parallel, hydro-mechanically-coupled simulation software (Irazu) based on the finite-discrete element method (FDEM). Irazu is a general-purpose numerical simulation software which combines continuum mechanics principles with discrete element algorithms to simulate the mechanical response of brittle geomaterials. To overcome the computational limitations of FDEM codes, Irazu utilizes the parallel processing power of general-purpose graphics processing units (GPGPUs). As a result, Irazu shows impressive speedups compared with a sequential central processing unit (CPU) FDEM code. The code capabilities are illustrated herein by simulating the complex failure mechanics of bedded rock samples. A case study to assess the stability of the overhang of a mine loading pocket demonstrates Irazu's application to field-scale problems. Overall, superior physics and computational performance make Irazu a state-of-the-art, commercial simulation tool for tackling complex geomechanical applications in mining, civil, and petroleum engineering.
Conventionally, numerical approaches used in rock mechanics are based on either continuum or discrete (discontinuum) formulations. These approaches fail to capture the emergence of new discontinuities generated by brittle fracturing processes. Over the last decade, multiple numerical approaches have been developed and applied to overcome this limitation (Lisjak & Grasselli, 2014). Among these methods, bonded discrete element models explicitly capture fracturing of brittle geomaterials by introducing cohesive contact models between the blocks or particles used to represent the solid structure. Alternatively, advanced continuum approaches, including the generalized finite element method (GFEM) and the extended finite element method (XFEM), have been proposed. In recent years, the combined (or hybrid) finite-discrete element method (FDEM) pioneered by Munjiza (2004) and implemented in the Y-Geo code (Mahabadi et al., 2012) has emerged as a promising technique to explicitly simulate fracture and fragmentation processes in brittle geomaterials. FDEM is an explicit numerical method which combines continuum mechanics principles with discrete element algorithms to simulate multiple interacting deformable and fracturable solids. While the elastic deformation of discrete bodies is described by the continuum finite element method (FEM), the contact detection and interaction of discrete bodies is captured using aspects of the discrete element method (DEM). The progressive mechanical breakdown and failure of rock material is represented using a cohesive fracture model.