Modeling and Simulation of Fracture Development and Caving Mechanisms in Longwall Mining Using FDEM: Analysis of Support–Rock Interaction and Energy Evolution

This study investigates the fracture development and caving mechanisms in longwall coal mining using powered roof supports (PRSs), simulated with the Finite–Discrete Element Method (FDEM) in Geomechanica’s Irazu platform. It is presented as an application study demonstrating the ability of this established FDEM platform to simulate fracture evolution and caving in a longwall environment, rather than as the development of a new model, criterion, or algorithm. A numerical model of a longwall face, including canopy, shield, and base components, was constructed in SolidWorks and imported for simulation. Fractured and intact coal zones were defined, and boundary conditions were applied to represent the mining advance sequence. Stress redistribution, fracture initiation, and subsequent caving behind supports were analyzed both with Irazu’s native tools and through advanced visualization in ParaView. Results revealed that fracture initiation occurs at the roof–canopy interface, propagating towards the gob and floor, eventually forming an elliptical caving pattern. Stress analysis highlighted critical loading at both canopy–roof and base–floor contacts, consistent with patterns reported in field and theoretical studies. Energy maps reveal elastic energy buildup prior to first break and its stepwise release during fracture propagation and caving. This application demonstrates the potential of FDEM to capture both the mechanical response of supports and the evolution of coal fractures, offering valuable insights for optimizing support design and ensuring roadway stability. These findings contribute to improved prediction and management of strata behavior in underground coal mining, bridging numerical modeling with practical engineering applications.