矿井开采过程中，多次采掘扰动所引发的循环加卸载效应对煤体力学性能的改变是导致冲击地压灾害发生的原因之一。揭示煤体在此过程中的关键力学参数响应特征及损伤机制可为冲击失稳状态判别提供依据，对提升灾害预测能力具有重要意义。

采用大尺寸类煤体试样，将准静态单轴循环加卸载和冲击动载相结合，精确捕捉试验过程中试样应力、应变以及声发射等响应信息，全面揭示多次采掘扰动作用下试样力学参数变化规律及损伤演化过程。

结果表明：(1)最高加载载荷是影响多次循环加卸载作用下损伤煤体力学性能的最关键因素，随着循环次数的增加，对于加载至屈服阶段的试样，其残余应变呈现先增大后减小再增大的变化趋势，耗散能密度及加载至最高载荷时所对应的声发射特征值逐渐增大，试样损伤程度不断增加；对于加载至弹性阶段的试样，其上述力学特征参数均呈现先减小后增大的变化趋势；而对于试验过程始终处于压密阶段的试样，3组数据均呈现不断减小的变化趋势。(2)在施加冲击动载作用后，3组试样均发生冲击破坏，前期准静态循环加卸载试验中所受载荷越小的试样，其损伤程度越小，发生冲击破坏所需的诱发动载强度越大，峰值破坏弹性模量越大。(3)从应变与能量2个角度对试样损伤度进行表征，通过对比分析，发现能量损伤度对此试验过程中试样损伤程度判别更为敏感。(4)对试样孔洞内部冲击破裂特征观察发现，试样在发生冲击破坏过程中共经历平静期、颗粒弹射期、稳定破坏期以及冲击破坏期4个阶段。(5)可将循环加卸载后期残余应变增大起始值以及冲击破坏过程中稳定破坏前期阶段作为损伤煤体冲击失稳前兆预警信息。研究获得了受多次采掘扰动煤体力学特性的演化规律，可为工程中损伤煤体冲击失稳状态判别提供理论依据，对于及时发现损伤煤体的潜在失稳风险，从而优化支护方案，确保矿井安全开采具有重要意义。

In the mining process of coal mines, the cyclic loading and unloading effects caused by multiple mining disturbances can alter the mechanical properties of coals, serving as a significant cause of rock bursts. Revealing the response characteristics of crucial mechanical parameters and the damage mechanisms of coals can provide a basis for discriminating the impact-induced instability state, holding great significance for enhancing disaster prediction capabilities.

Quasi-static uniaxial cyclic loading and unloading experiments and the dynamic impact loading experiments on large-size coal-like specimens were combined to accurately capture the stress, strain, and acoustic emission responses during the experiments, thoroughly unveiling the laws of changes in mechanical parameters and the damage evolutionary processes of the specimens under the action of multiple mining disturbances.

Key findings are as follows: (1) The maximum load is identified as the most critical factor influencing the mechanical properties of the coals damaged by multiple cyclic loading and unloading processes. With an increase in the number of cycles, the specimen in the yield stage under loading displayed increasing, decreasing, and then increasing residual strain. Meanwhile, it exhibited gradually increasing dissipated energy density and acoustic emission characteristic value corresponding to the maximum load, suggesting escalating damage degrees of the specimens. For the specimen in the elastic stage under loading, all the mechanical parameters mentioned above first decreased and then increased. In contrast, for the specimen remaining in the compaction stage throughout the experiment, the three sets of data manifested gradually decreasing trends. (2) Under dynamic impact loading, all of the three specimens experienced impact-induced failure. The specimen subjected to a lower load in the earlier quasi-static cyclic loading and unloading experiments exhibited less damage, higher dynamic load strength required for impact-induced failure, and higher elastic moduli corresponding to the failure at peak strength. (3) The damage degrees of the specimens were characterized from both strain and energy perspectives. A comparative analysis revealed that energy damage degrees proved more sensitive in discriminating the damage degrees of the specimens in the experiment process. (4) Observations of the impact fracture characteristics inside the specimens suggest that the specimens experienced the quiet, particle ejection, stability failure, and impact-induced failure stages in the process of impact-induced failure. (5) The value of residual strain, when it began to increase, in the late stage of cyclic loading and unloading, as well as the early stage of stability failure in the impact-induced failure process can be used as early-warning information for the impact-induced instability of damaged coals. This study, having obtained the evolutionary patterns of the mechanical properties of coals subjected to multiple mining disturbances, can provide a theoretical basis for determining the impact-induced instability state of damaged coals in engineering construction. Furthermore, it holds great significance for promptly identifying the potential instability risks of damaged coals and thereby optimizing the supporting schemes and ensuring the safe mining of mines.