Li Shengwei, Li Yexue, Zeng Gang
School of Civil Engineering and Architecture, Hubei University of Arts and Science, Xiangyang, 441053, Hubei, China.
Faculty of Engineering and Natural Sciences, Tampere University, POB 589, Tampere, 33014, Finland.
Sci Rep. 2024 Oct 24;14(1):25204. doi: 10.1038/s41598-024-76075-9.
To study the dynamic mechanical characteristics of coal in the area affected by mining in front of the mining face under different mining methods, an improved split Hopkinson pressure bar (SHPB) was used to apply different static loads to different positions. Then, dynamic mechanical tests were conducted on coal at different positions on the mining face, analyzing the dynamic response under strong dynamic load disturbances, under three different mining layouts. Within the range of static water pressure to the peak support pressure, the dynamic strength of coal gradually increases with increasing distance from the mining face. The dynamic strength is the smallest at the peak support pressure stress, and under strong external disturbances, instability and failure are increasingly likely to occur at the peak stress. Under the same loading rate conditions, the dynamic strength of the peak stress in coal is as follows: Protective coal-seam mining (PCM) > Top-coal caving mining (TCM) > Nonpillar mining (NM).
为研究不同开采方法下采面前方采动影响区域煤体的动态力学特性，采用改进型分离式霍普金森压杆（SHPB）对不同位置施加不同静载。然后，对采面上不同位置的煤体进行动态力学试验，分析三种不同开采布局下在强动态载荷扰动作用下的动态响应。在静水压力至峰值支承压力范围内，煤体的动态强度随距采面距离的增加而逐渐增大。在峰值支承压力应力处动态强度最小，在强外部扰动下，峰值应力处越来越容易发生失稳破坏。在相同加载速率条件下，煤体峰值应力的动态强度排序为：保护层开采（PCM）＞放顶煤开采（TCM）＞无煤柱开采（NM）。
