The analysis of efficiency decline of methods for hydraulic influence on outburst-prone coal seams in the conditions of large depths is represented. The models are considered for parameters calculation of high-pressure liquid injection, based on the hypotheses of the stress-strain state formation of the coal seam; the patterns of rock pressure manifestation as well as calculation discrepancy between the liquid injection pressure and the terms of large depths, are established. It is shown that in the parameters calculation of the high-pressure liquid injection, it is necessary to take the height of the column of rocks which lost their integrity and form the stratification zone in the underworked massif instead of depth Н of the seam mining. It has been established that the efficiency of hydro-loosening depends not only on the injection pressure, but also on the location of borehole filtration part relative to the maximum of abutment zone.

The paper presents the results of mining and experimental work, bench tests and theoretical studies of the energy characteristics of the stationary and pulsating fluid flow, which allow to estimate the efficiency of the cavitation generator in the hydro impulsive loosening of an outburst-prone coal-bed. The active stage of the hydro impulsive loosening and the effective range of the amplitude-frequency (AF) spectrum of the generator operation acoustic signal have been established by the AF spectrum of the sound accompaniment of the hydro impulse impact and the backup pressure of the liquid in the well. By calculation for this range the energy characteristics of the static and dynamic components of the pulsating fluid flow were determined. This made it possible to determine that the efficiency of the cavitation generator, all other conditions of the coal-bed hydro loosening being equal, is 4.8–1.2 times higher than the efficiency of the static impact.

The paper represents the results of monitoring and evaluation of the efficiency of hydroimpulsive disintegration of outburst-prone coal seams in the stopes of development mine workings using a system of sound detecting facilities. Methods of acoustic emission control have been considered as well as the monitoring tasks to evaluate rock mass conditions before the procedure and after it inclusive of the results of sound accompaniment of hydraulic disintegration of the coal seam. It has been determined that the higher concentration of stresses within the rock mass is, the more efficient action of high frequency self-oscillations of cavitation transmitter is on both the fissuring and changes in gas-dynamic state of the coal seam. It has been recommended to apply a mode of impulsive fluid pumping under the conditions where coal seam is in the stress-strain state.