瓦斯煤岩变形破裂过程声发射预警信号变化规律研究

Acoustic Emission Warning Signals Change Law Research during Deformation and Failure of Gassy Coal Rock

为提高矿井瓦斯突出灾害预测准确率,基于力学、声学理论,采用实验室试验方法,以标准煤试样为研究对象,对含瓦斯煤岩变形破裂过程声发射(AE)预警声信号变化规律进行研究。试验结果表明:围岩应力增大,煤岩破裂由低围岩应力的脆性破坏逐渐过渡到高围岩应力状态的塑性破坏,可根据声发射高幅信号提前预测煤岩破裂时刻。瓦斯的力学和非力学作用对煤岩体力学性质和变形特性的影响均随瓦斯压力的增加而变大。瓦斯压力越大,则煤岩破裂进程加快,积累的声发射能量迅速释放,高值振铃计数声发射信号覆盖时间区段变长,声发射信号能及时反映含瓦斯煤岩的不稳定性。

In order to improve the mine gas outburst prediction accuracy, AE warning signal variation in the process of gas-coal deformation and fracture was studied using laboratory experimental methods and standard coal samples. The study results show that after the confining pressure of coal increases, coal crack changes gradually from brittle failure under low confining pressure to ductile failure under high sur- rounding stress, that by the AE signal can predict the time of coal failure in advance, that the mechanical and non-mechanical effect of gas on the coal mechanical properties and deformation characteristics increase with the gas pressure increasing, that when gas pressure increases, coal cracks more rapidly, AE energy accumulated releases rapidly, time coverage period of AE signal high ring count value becomes longer, and that the AE warning signal can reflect gas-coal instability timely.