2026/07/20 by Zhen Qiao, Chengwu Li
Engineering · #Coal Properties and Utilization #Rock Mechanics and Modeling #Combustion and Detonation Processes
paper · doi:10.1016/j.fuproc.2026.108538
High stress, high gas, and deteriorated coal mechanical properties in deep mining combine to significantly aggravate the difficulty of coal and gas outbursts prevention and control. The rapid ejection of massive fragmented coal entrained by high-pressure gas is the core disaster-causing process of such hazards. Most existing studies focus on energy evolution, yet the essence of mechanical failure under gas-coal coupling remains inadequately revealed. Accordingly, this study analyzed the outburst process through experimental, theoretical and numerical approaches based on fracture mechanics. The main conclusions were drawn as follows. Experimentally, using a self-developed test system, this study found that the total crushing surface area of coal particles exhibited a first-increasing-then-decreasing trend with rising release pore diameter. The peak appeared at 1.5 cm and the trough at 3.5 cm, with a maximum difference of 208.1073cm 2 . Theoretically, incorporating the stress intensity softening effect of gas-bearing coal, optimized the critical crack propagation criterion for coal particles under high-pressure gas release. Energy distribution calculations showed that the kinetic energy proportion increased from 37.91% (1.5 cm) to 61.97% (3.5 cm), further consolidating the theoretical basis of this criterion for interpreting experimental phenomena. Numerically, a computational model was established by coupling Peridynamics with the optimized critical criterion. The predicted fragmentation surface area was in relatively good agreement with experimental results, with a maximum relative error of 2.3% (absolute value: 2.1642cm 2 ), and the model well reproduced the influence of release pore diameter on coal particle fragmentation. These findings provide a new analytical path for systematic understanding of coal and gas outburst processes. They help deepen insights into outburst disaster mechanisms and offer theoretical reference for precise prevention, control and accident tracing of outburst disasters under deep mining conditions.