This study aimed to investigate the influence of local frequent dynamic disturbance on micro-structure evolution in different zones of coal-rock. To do so, we carried out a systematic experimental research on the micro-structure evolution of briquette and raw coal samples under local impact load by using self-developed pendulum hammer dynamic impact loading test device of coal-rock and ultrasonic testing equipment, and analyzed the localization effect of local impact load. The results show that M_n (micro-structure cumulative change factor) of briquette coal samples presents an inclined M-shaped four-stage evolution mode along and perpendicular to impact direction with cyclic impact times under conventional full impact load, whereas it shows more obvious anisotropy and localization under local impact load. M_n for both conventional full impact and local impact shows a nonlinear increasing trend with the increase in impulse, but their increasing gradients are different. The critical zone is the most affected, the impact zone comes next, and the non-impact zone is the least affected with the increase in impulse under local impact load. M_n in the impact zone and critical zone decreases exponentially with the increase in the impact loading area, while it increases exponentially in the non-impact zone. The micro-structures evolution in briquette and raw coal samples is similar, but the anisotropy and localization effect of micro-structure evolution for raw coal samples are more significant and more sensitive to the impact loading area. The micro-structure evolution of coal-rock under local impact load shows obvious localization effect. M_n in the critical zone is usually the largest, M_n in the impact zone is slightly less than that in the critical zone, and M_n in the non-impact zone is the least. The larger the impact loading area, the wider the influence enhancement area, and the smaller the non-influence area, yet the smaller the impact zone and critical zone are affected by local impact load.

本研究旨在探讨局部频繁动力扰动对煤岩不同区域微观结构演化的影响。为此，我们利用自行研制的摆锤煤岩动冲击载荷试验装置和超声试验设备，对局部冲击载荷下煤球和原煤样品的微观结构演变进行了系统的实验研究，并进行了分析。局部冲击载荷的局部化效应。结果表明，团块煤样品的M _n（微观结构累积变化因子）呈现出一个倾斜的M形的四阶段演化模式，在传统的全冲击载荷下沿冲击方向并垂直于冲击方向，具有周期性的冲击时间，而在局部冲击载荷下具有更明显的各向异性和局域性。常规全冲击和局部冲击的M _n随脉冲的增加呈非线性增加趋势，但它们的增加梯度不同。在局部冲击负荷下，随着冲击的增加，关键区域受影响最大，冲击区域次之，非冲击区域受影响最小。中号_ñ冲击区和临界区中的载荷随冲击载荷面积的增加呈指数下降，而非冲击区中的载荷呈指数增长。煤球和原煤样品的微观结构演变相似，但原煤样品的微观结构演变的各向异性和局部化效应更加显着，并且对冲击载荷区域更敏感。局部冲击载荷作用下煤岩的微观结构演化表现出明显的局部化作用。中号_ñ在临界区通常是最大的，中号_ñ在冲击区略显不足的是在关键区域，中号_ñ在非影响区中的最小。冲击载荷区域越大，影响增强区域越广，非影响区域越小，但是局部冲击载荷对冲击区域和临界区域的影响越小。