Yan Jin, Ni Xiaoming, Su Erlei, Niu Ruize
School of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo, 454000, Henan, China.
Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization, Jiaozuo, 454000, Henan, China.
Sci Rep. 2025 Apr 3;15(1):11487. doi: 10.1038/s41598-024-80814-3.
Stable underground tunnels and gas drainage boreholes are important guarantees for safe and efficient coal mining. The stability of these structures is closely related to the mechanical properties of coal and rock damage. Accurate quantification of coal and rock damage factors is a prerequisite for objective evaluation of damage mechanics. In order to study the relationship between coal and rock damage factors and fracture structure parameters in coal, the "CT scanning + Avizo image processing" method was used to reconstruct the three-dimensional spatial morphology of fractures in coal samples from the Yuwu Mine in Shanxi Province, China. The construction of a parameter system for evaluating the spatial structure of fractures represents the three-dimensional composition of fractures. Combined with uniaxial compression tests, a mathematical model for coal damage factors based on fracture spatial structure parameters was established, and the influence of fracture parameters on the mechanical properties of coal damage was discussed. The results show that fractal dimension, spatial attitude factor, and discreteness can respectively characterize the complexity of fracture morphology, the impact of fracture spatial angles on compressive strength, and the spatial discreteness of fractures; coal damage factors are positively correlated with porosity and spatial attitude factors, and negatively correlated with fracture fractal dimension and fracture discreteness. The mathematical model of coal rock damage factors established in this study has a correlation with experimental test values that is 0.3174 higher than that of traditional damage factor models, which can more objectively characterize the mechanical damage characteristics of coal rock. In summary, this study provides an efficient and accurate method for the quantitative characterization of coal body damage factors considering the characteristics of fracture space structure.
稳定的地下巷道和瓦斯抽采钻孔是煤炭安全高效开采的重要保障。这些结构的稳定性与煤岩损伤的力学性质密切相关。准确量化煤岩损伤因子是客观评价损伤力学的前提。为了研究煤岩损伤因子与煤中裂隙结构参数之间的关系，采用“CT扫描+Avizo图像处理”方法对中国山西省峪口煤矿煤样裂隙的三维空间形态进行了重构。构建裂隙空间结构评价参数体系，表征裂隙的三维组成。结合单轴压缩试验，建立了基于裂隙空间结构参数的煤损伤因子数学模型，并探讨了裂隙参数对煤损伤力学性质的影响。结果表明，分形维数、空间姿态因子和离散度分别可以表征裂隙形态的复杂性、裂隙空间角度对抗压强度的影响以及裂隙的空间离散性；煤损伤因子与孔隙率和空间姿态因子呈正相关，与裂隙分形维数和裂隙离散度呈负相关。本研究建立的煤岩损伤因子数学模型与试验测试值的相关性比传统损伤因子模型高0.3174，能更客观地表征煤岩的力学损伤特性。综上所述，本研究提供了一种考虑裂隙空间结构特征的煤体损伤因子定量表征的高效准确方法。
