利用MTS815岩石力学试验系统对煤岩试样进行常规单轴和三轴围压下的声发射(AE)试验。对声发射信号特征进行综合分析，结果表明：常规单轴压缩和围压作用下试样的AE参数变化均具有明显的趋势性;围压的作用下，弹性阶段的声发射信号显著减少，破坏前无明显AE相对平静期现象，随时间分布的AE振幅及其包络线可以间接反映应力的变化趋势。随着振幅的增加，声发射事件数呈递减的趋势，反映累积幅度分布的m值随着围压的增加而增大。AE频率均分布在3个频域范围内，试样破坏时AE主频成分所占比例显著增加。

This paper conducts experimental investigation on acoustic emission(AE) characteristics of coal rock at uniaxial and triaxial compression by MTS815 rock mechanics test system. The results show that the variation of AE has tendency effect at uniaxial compression and confining pressure experiments. We indicate that AE signal decreases significantly in the elastic stage, and the relatively quiet period of AE before the specimens failure is not obvious under confining pressure. The AE amplitude distribution with time and its envelope line can indirectly reflect the trend of stress. The AE events peak stress and elastic modulus decrease with the temperature increase, and the value of m which reflects the cumulative distribution of amplitude increases as the confining pressure rises. The results also show that the AE frequency distributes in three frequency domains, and the proportions of dominant frequency significantly increase while the specimens are broken.

国家自然科学基金资助项目(50674111)