A DEM-enhanced mesoscale modeling framework for bimrocks with high rock block proportion and spatial variability

Block-in-matrix rocks, often referred to as bimrocks, constitute geological formations characterized by their heterogeneous structure, combining rock blocks with a weak matrix. Many significant engineering projects are closely associated with these bimrocks. However, due to the challenges in constructing mesoscale models of bimrocks with a high proportion of rock blocks (RBP) and spatial variability, numerical simulations for these geological materials are rare. With this in mind, a discrete element method (DEM) packing approach with periodic boundaries is employed to create mesoscale models with higher RBPs and spatial variability. Furthermore, the study introduces the rigid block discrete element method (RB-DEM) with a reduced-number contact to efficiently simulate mesoscale bimrocks. The excellent agreement between simulation and experimental results attests to the feasibility of this method. Additionally, the paper investigates the effects of RBP, spatial variability of rock blocks, and the strength of the block-matrix interface on the uniaxial compression strength (UCS) of bimrocks. It provides an authentic and efficient tool for modeling and simulation of these geological materials. • High-block bimrock modeling challenges cause scarce numerical simulations. • DEM packing with periodic boundaries generates high-block, variable bimrock models. • RB-DEM with contact reduction efficiently simulates bimrocks; experimental agreement proves feasibility. • Study examines RBP, block distribution, and interface strength effects on bimrocks' uniaxial compression strength.