3D characterization of fracture evolution and energy release in granite under static expansive loading using DIC, AE, and CT

This study investigates the 3D fracture evolution and energy release in granite blocks containing single and dual holes under static expansive loads induced by soundless cracking demolition agents. The spatiotemporal correlation between fracture evolution and energy release is captured through integrated digital image correlation (DIC), acoustic emission (AE), and computed tomography (CT) techniques. Results showed that both configurations initiate cracks at the borehole perimeter and undergo a critical transition near the free boundary, leading to rapid penetration. Compared with single-hole, dual-hole specimens exhibited more directional and efficient crack propagation with higher AE energy release, reflecting stress superposition effects. The integrated use of DIC, AE, and CT provided a comprehensive characterization of surface deformation, internal cracking, and spatiotemporal energy distribution. • Integration of DIC, AE, and CT reveals a strong correlation between cracking and energy release. • Dual-hole specimens show directional path, higher efficiency, and concentrated energy. • Critical transition near the free boundary as a surge in strain energy release triggers crack penetration.