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Abstract The uniaxial compression acoustic emission tests of dry and saturated coal gangue were performed. The acoustic emission precursor laws of deformation and failure of coal gangue were researched based on the dominant-frequency and entropy changing of acoustic emission signal. The results show that drying and saturated coal gangue have two dominant-frequency bands of about 20 kHz and 30–60 kHz. The acoustic emission signal dominant-frequency of coal gangue has a mutation before the rupture of rock，and it is close to 0 and 100 kHz. The entropy of dry coal gangue concentrates in 0.5 to 2.0 without a mutation；and the entropy of saturated coal gangue concentrates in 0.0 to 0.5 and has a mutation. Acoustic emission signal entropy can evaluate the stability of coal gangue. when the entropy is greater than 1.0，it indicates the increasing of risk of the instability of coal gangue. The dominant-frequency focusing on about 0 and 100 kHz can be seen as a precursory characteristic of coal gangue rupture. Due to the saturated characteristic of the actual mining rock，as well as the complexity of its deformation and destruction，the dominant-frequency and entropy can be combined used to obtain an early warning information of coal dynamic disaster based on acoustic field parameter variation. The experimental results provide a new method and basis for research on rock damage evolution mechanism and rupture forecast，which has an important theoretical study significance for acoustic emission monitoring and early warning for the actual mining dynamic disaster of coal.
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2015, Vol. 34 
