CT-based 3D Reconstruction and CDEM Simulation of Mechanical Behavior in Conglomerates

The study of conglomerate mechanical properties is challenging due to their inherent heterogeneity and the limitations of conventional testing methods, which often yield highly scattered data. This research develops an integrated methodology combining CT-based 3D reconstruction with continuum-based discrete element method (CDEM) simulations to investigate conglomerate mechanical behavior. A novel calibration framework is introduced that leverages indentation hardness tests to provide independent physical constraints on the gravel-matrix strength ratio. The framework adopts a 5% error threshold grounded in established rock mechanics literature as the accuracy criterion for macroscopic mechanical parameters. It also employs post-failure CT imaging to validate simulated fracture patterns against experimental observations at the mesoscopic scale. Using this validated approach, the effects of interface strength, gravel-matrix strength ratio, gravel content, spatial distribution, and particle size on mechanical properties are systematically investigated. Results reveal that high-strength interfaces enhance mechanical strength by restricting fracture propagation. Conglomerates with a gravel-to-matrix strength ratio of 1.5 demonstrate strong damage resistance, while those with ratios of 2-2.5 resist deformation more effectively. Predictive curves illustrate the relationship between gravel content and mechanical parameters; influenced by spatial distribution variations, mechanical parameters exhibit fluctuations around the curve, with compressive strength variability peaking at 25% gravel content. Specific gravel radii improve structural stability, yielding maximum compressive strength and elastic modulus. This study provides new insights into conglomerate mechanical properties and establishes a transferable methodology for simulating other heterogeneous geomaterials.