Damage and Fracture Behavior of Granite, Sandstone, and Basalt Under Liquid Oxygen Blasting: Rock Property Effect and Failure Mechanism

ABSTRACT Liquid oxygen blasting is an efficient nonexplosive rock‐breaking method in geotechnical engineering, yet its rock fragmentation behavior and cross‐section formation mechanism remain unclear. This study systematically investigates the fragmentation characteristics of rocks subjected to liquid oxygen blasting through laboratory experiments on different lithologies. Strain testing, block size distribution analysis, and characteristic fragment observation were combined to reveal the failure process. The results indicate that liquid oxygen blasting is essentially a gas‐driven blasting process, and rock damage can be divided into a fluctuation stage and a pneumatic stage. The final fragmentation effect is controlled by the combined action of these two stages. High‐pressure gas tends to expand along weak directions at fracture tips, whereas higher rock strength inhibits gas expansion toward free surfaces. In addition, pore distribution affects fracture morphology and crack propagation: Denser pores result in rougher cross‐sections and more cracks. These findings provide theoretical guidance for understanding and applying liquid oxygen blasting.