Gao Xin, Xue Sheng, Qingyi Tu
School of Safety Science and Engineering, Anhui University of Science and Technology, Huainan, 232001, Anhui, China.
Joint National-Local Engineering Research Centre for Safe and Precise Coal Mining, Anhui University of Science and Technology, Huainan, 232001, Anhui, China.
Sci Rep. 2025 Jan 2;15(1):227. doi: 10.1038/s41598-024-84005-y.
To investigate the dynamic compression properties and crushing features of gas-containing coal under complex geological environments, a dynamic and static combined loading test system was independently developed for conducting triaxial dynamic compression tests. The dynamic stress-strain curves under different strain rates were analyzed to study the effects of strain rate and gas pressure on the dynamic mechanical characteristics. Crushed coal samples were sieved and analyzed using a standard sieve and fractal theory. The study reveals that strain rate and gas pressure significantly influence the plastic deformation stage of the dynamic stress-strain curve of gas-containing coal. Under high strain rates, low gas pressure lengthens the plastic deformation stage, while high gas pressure shortens this stage and enhances brittleness. Increased strain rates lead to higher peak stress and peak strain in gas-containing coal samples. As gas pressure increases, the dynamic peak stress decreases, and the peak strain initially increases and then decreases. The damage form of gas-containing coal is primarily tensile-shear, accompanied by crushing damage. The fractal dimension increases at higher gas pressures and strain rates but stabilizes at gas pressures greater than 0.7 MPa. These findings enhance the understanding of the dynamic behavior of gas-containing coal under triaxial loading and provide valuable insights for the prevention and control of dynamic hazards in gas-containing coal bodies under complex stress environments.
为研究复杂地质环境下含瓦斯煤的动态压缩特性及破碎特征，自主研发了动静组合加载试验系统，进行三轴动态压缩试验。分析不同应变率下的动态应力 - 应变曲线，研究应变率和瓦斯压力对动态力学特性的影响。对破碎煤样用标准筛进行筛分，并运用分形理论进行分析。研究表明，应变率和瓦斯压力对含瓦斯煤动态应力 - 应变曲线的塑性变形阶段有显著影响。在高应变率下，低瓦斯压力会延长塑性变形阶段，而高瓦斯压力则会缩短该阶段并增强脆性。应变率增加会导致含瓦斯煤样的峰值应力和峰值应变升高。随着瓦斯压力增加，动态峰值应力降低，峰值应变先增大后减小。含瓦斯煤的破坏形式主要为拉剪破坏，伴有压碎破坏。在较高瓦斯压力和应变率下，分形维数增大，但在瓦斯压力大于0.7MPa时趋于稳定。这些研究结果加深了对含瓦斯煤三轴加载下动态行为的理解，为复杂应力环境下含瓦斯煤体动力灾害防治提供了有价值见解。
