Experimental Study on Mechanical Characteristics and Acoustic Emission Characteristics of Coal with Different Saturation and Impact Tendency

Using RMT-201 rock and concrete mechanical test system, uniaxial compression tests of coal with different water saturation and impact tendency were carried out. The results show that the saturation of coal is closely related to its mechanical properties, and the strength of coal sample decreases with the increase of water saturation; The change trend of acoustic emission of coal with different water saturation is basically consistent, but the emission activity of coal with low water saturation is larger, and the active stage is ahead of that of coal with high water saturation; The relationship between coal burst tendency index and water saturation is nonlinear, which can be fitted by Boltzmann model. It is obtained that the burst tendency index decreases in a “ladder” manner with the gradual increase of water saturation. Therefore, the model can correctly reflect the relationship between different saturation of coal sample and its impact tendency index, which has important guiding significance for the prevention and control of rock burst havoc.