Application of shock blasting mode in mine roadway construction

Abstract

Purpose. Working out measures providing safe application of a shock blasting mode while driving workings in outburst-prone coal seams. Methods.Conveying of shock blasting at the mine workings on the coal mines of Ukraine is regulated by a number of specification documents. At the same time, in the process of shock blasting production numerous technological violations of the mode take place and there are often gas-dynamic phenomena, including those with death of people. The mode of shock blasting at mines is used for unworked coal breaking on outburst-prone seams regardless of results of prognosis and efficiency of antilanding measures done, at troublesome seams in the zones where the reading "prone" is set by latest estimate; and while driving in outburst-prone coal seams.Findings. Shock blasting is used at mines at mines in rather wide range of mining and geological conditions. It is recommended to apply the methods of intensity and frequency of gas and oil emissions attenuation at shock blasting on especially outburst-prone layers. The methods of depth increase of pre-face part of a coal bed unloading zone are used. The increase is achieved by means of heading rock loosening of adjacent strata, advanced blasting, blast hole charge operation in adjacent strata, front-rank loosening (camouflet blasting) of coal bed. Moreover, the blasting pattern with formation of piled blocking retaining wall is applied.Originality. The main scientific and technical principles of the safe and efficient use of a shock blasting mode in blast hole drilling driving in outburst-prone coal seams and beds are formulated. Practical implications.Applying shock blasting mode in mine workings conveying proved to be one of the safest methods to prevent gas-dynamic phenomena. Simultaneously, as a rule, this method is one of the most costinefficient methods especially when paced work of coalmine is vital. Therefore, basic research directions are to be continued towards reduction of expenses and increase of this method application efficiency.

Numerical simulation of the stress-strain state of a coal seam caused by an explosion of a blast-hole charge with an annular gap

“…It manifests itself in spontaneous instantaneous destruction of a part of the coal seam near the mine workings, throwing of the destroyed coal into the worked-out space and enhanced gas emission. "Shock blasting" mode of the edge part of the coal seam is often used among the various measures used to reduce the risk of sudden outburst of coal and gas emission [2]. Shock blasting can either provoke gas-dynamic destruction of a part of the coal seam in the form of local outburst (but this removes the factor of instantaneity) [2,3], or to create conditions for the quiet degassing of the coal seam and the subsequent reduction of the probability of coal and gas emissions [4][5][6].…”

“…"Shock blasting" mode of the edge part of the coal seam is often used among the various measures used to reduce the risk of sudden outburst of coal and gas emission [2]. Shock blasting can either provoke gas-dynamic destruction of a part of the coal seam in the form of local outburst (but this removes the factor of instantaneity) [2,3], or to create conditions for the quiet degassing of the coal seam and the subsequent reduction of the probability of coal and gas emissions [4][5][6]. The ambiguous effect of the explosive impact on the gas-saturated coal seam has not yet received a theoretical explanation and the mechanism of its action is not clear, but to study its impact on the coal seam, various studies are being undertaken.…”

Features of initiating the light-sensitive explosive composites for safe blasting of borehole charges in coal mines

“…Such issues as safe use of blasting agents, their reliability and operational precision as well as their environmental, technological, and economic efficiency are becoming more and more important in the process of wide-scale blasting of borehole or downhole explosive charges. There will be enough to mention organization of the operations during underground coal mining, open-pit iron-ore mining and building material extraction [4,5]. It becomes clear that the solution of those problems is connected immediately with the solution of a key problem -development of the technology and synthesis of innovative priming explosives [6 -8] which properties correspond to the requirements of modern technologies, and systems of their initiation [9].…”

Justification of the parameters for safe blasting of floor rocks in the roadway driven through the hazardous by outbursts sandstones

“…The blasting operations for ripping the floor rocks were conducted in the experimental roadway according to the Blasting Pattern developed by the Pokrovskoe Mine jointly with the IGTM [4,5,15,16]. Prior to perform the blasting operations, the following requirements of the Safety Regulations (SR) were included into the Blasting Pattern [4,5,17]:…”