Selection of technological parameters for a development drift and a local method to prevent gas-dynamic phenomena

The objectives of the study were to select the parameters for a development drift with account of the effect the mining operations have on formation of the gas dynamic phenomena, to develop a method of advance deformation and degassing of the coal seam, to clarify the cause-and-effect regularities in formation of the energy and dynamic interaction processes in the coal-rock massif and to justify the safe face advance criterion. The cause-and-effect method of comparing the guiding documents with the real characteristic of the outburst coal showed that the properties and attributes in the recommendations do not reflect the gas-dynamic hazard properties. Different ingredients and facies conditions of the coal seam formation have not been taken into account. The hazard of the coal seams is represented by irrelevant properties, and the interpretation of this hazard as a spontaneous gas outburst from the coal seam or the processes of energy accumulation and flow in the coal-rock massif covers the development of real methods to forecast and prevent this phenomenon. The article for the first time ever formulates a new hypothesis of the gas-dynamic phenomena in mining workings. In contrast to the existing concepts, the gas-dynamic phenomenon is a natural phenomenon that is local in nature and is a reaction of the stressed-and-strained rock massif to the advance of the coal face. The method preventing a sudden outburst of methane from the coal seam is methane capture in the relief holes using a vacuum pump and its removal via pipes to the ventilation workings or to the surface. With the depth of the relief holes of 30 metres, the face advance rate can be increased up to 13 metres per day.