Investigations into crack evolution during controlled continual laser-based rock processing

Laser-based rock processing presents a transformative approach for mining, drilling, tunnelling, and geothermal applications by addressing key limitations of conventional mechanical methods, including excessive tool wear and operational inefficiencies. Despite its promise, challenges such as anisotropic rock behaviour, power transmission, formation damage, and instability in subsurface conditions require further investigation. This study examines the effectiveness of continual laser-based rock processing in inducing controlled damage and crack propagation in limestone rock. Distinct stages of rock failure – ranging from pore initiation to fragmentation and segmentation – were identified, revealing a progressive transition from microstructural alteration to macroscopic fracturing. A customized image analysis framework was employed to asses subsurface crack patterns, qualitatively and quantitatively with high fidelity, offering a robust tool for damage quantification. The results underscore the potential of controlled continual laser pulsing as a reliable method for targeted rock disintegration and highlight the role of image-based evaluation in advancing the mechanistic understanding of laser-rock interaction. These findings are expected to contribute positively for the development of next-generation rock-breaking and excavation technologies.