Chen Yan, Zhang Guolong, Guo Baohua, Dou Rong
School of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo, Henan 454000, China.
Henan Key Laboratory for Green and Efficient Mining & Comprehensive Utilization of Mineral Resources, Henan Polytechnic University, Jiaozuo, Henan 454000, China.
ACS Omega. 2023 Mar 9;8(11):9896-9903. doi: 10.1021/acsomega.2c06840. eCollection 2023 Mar 21.
The size ranges of ore pillars play important roles in preventing the occurrences of rock burst phenomena. Due to the lack of research on the relationship between crack evolution behaviors and bursting liability of rocks with different sizes, uniaxial compression tests on sandstone with different height-to-diameter ratios (/) were conducted. The results showed that the mechanical parameters of sandstone have obvious size effects, in which both the peak strength and peak strain decrease with increases in the /. Moreover, the brittle index modified value (BIM) decreased, but the impact energy index increased gradually, which indicated the increase of bursting liability. With the increases in the BIM, the overall crack strain parameters increased, thereby indicating a positive correlation. With the increase in the impact energy index, the crack strain decreased and the bursting liability became higher. Although the axial crack closure stress and axial crack damage stress increased with the increases in BIM (indicating a positive correlation), the bursting liability became increasingly smaller. The crack stress decreased with the increases in the impact energy index, and the bursting liability became stronger. The findings of this study will potentially provide experimental references for furthering the current understanding of the mechanism of rock bursts in underground coal mines in China.
矿柱尺寸范围在防止岩爆现象发生方面起着重要作用。由于缺乏对不同尺寸岩石裂纹演化行为与冲击倾向性之间关系的研究，对不同高径比（/）的砂岩进行了单轴压缩试验。结果表明，砂岩力学参数具有明显的尺寸效应，其中峰值强度和峰值应变均随/的增大而减小。此外，脆性指数修正值（BIM）减小，而冲击能量指数逐渐增大，这表明冲击倾向性增加。随着BIM的增加，整体裂纹应变参数增大，从而表明存在正相关关系。随着冲击能量指数的增加，裂纹应变减小且冲击倾向性变得更高。虽然轴向裂纹闭合应力和轴向裂纹损伤应力随BIM的增加而增大（表明存在正相关关系），但冲击倾向性变得越来越小。裂纹应力随冲击能量指数的增加而减小，且冲击倾向性变强。本研究结果可能为进一步了解中国地下煤矿岩爆机理提供实验参考。
