Experimental study on rock burst tendency of coal with different moisture content based on acoustic emission time-frequency signals

In order to explore the correlation between the time-frequency characteristics of the acoustic emission of wa- ter-bearing coal sample and its index of rock burst tendency,taking the 7609 working face of Gengcun as an example, the rock burst tendency law of coals with different moisture contents and the correlation between the rock bust tenden- cy of coals and AE time frequency signals were studied comprehensively by experimental and signal processing meth- ods. There were coals under different moisture content states,saturated,natural and drying 24 hours. The results show that the distribution characteristics of AE time frequency signals obtained by monitoring the failure process of coals can be used to retrieve its loading stage. Based on the AE amplitude frequency signal,the damage scale of coals can be es- timated. The rock burst tendency and possibility of dynamic destruction can be inferred by the AE energy distribution in different frequency ranges. The AE inversion energy ratio Kae and frequency amplitude relative value ratio Kaf for coals rock burst tendency were defined. Selected the 7609 working face of Gengcun as an example,the feasibility of the time frequency characteristics of AE signals and the key parameters for detecting the rock burst tendency of coal were verified.