The experience of opening of the prone-to-outburst coal bed l3 in the Krasnolimanskaya mine by the tunneling machine

Heading set of equipment for underground development galleries drivage in rocks prone to gas-dynamic phenomena

“…In the developed device, the total compression force of the steel spring 8, which transfers the axial vibration load on the rock-breaking tool (2)(3)(4), is equal to the compressive strength of the rock during the penetration of the tool (2-4) into the rock. The torque of twisting the elastic pipe 7 to 3° in the direction opposite to the torque of the drill rod 1, which performs vibratory loading on the rockbreaking tool (2)(3)(4) in the plane of torque application, is equal to the shear strength limit of the rock on the entire face of the borehole or well.…”

“…At the first stage of rock destruction at the bottom of the borehole or well, the developed device presses the steel spring 8 to full compression at a distance of up to 3.0 mm. Decompression of the steel spring 8 begins on the fourth stage and additional penetration up to 3.0 mm of rock-breaking tool (2-4) into the face of a borehole or well takes place due to the higher speed of the steel spring 8 on the rockbreaking tool (2)(3)(4) in comparison with the speed of axial pressing application of the drill rod 1 of the developed device to the bottom of the borehole or well. The steel spring 8 in the device acts instantly as gunpowder ignited in the cartridge of a firearm, and the drill rod has an inertia of action on the rock-breaking tool (2)(3)(4).…”

“…Decompression of the steel spring 8 begins on the fourth stage and additional penetration up to 3.0 mm of rock-breaking tool (2-4) into the face of a borehole or well takes place due to the higher speed of the steel spring 8 on the rockbreaking tool (2)(3)(4) in comparison with the speed of axial pressing application of the drill rod 1 of the developed device to the bottom of the borehole or well. The steel spring 8 in the device acts instantly as gunpowder ignited in the cartridge of a firearm, and the drill rod has an inertia of action on the rock-breaking tool (2)(3)(4). So in the developed device at the beginning of the fourth stage of rock destruction at the bottom of the borehole or well it is assumed the decompression of the steel spring 8 on a distance δ, which is not more than 3.0 mm (see figure 2а).…”

“…Conditions of coal seams in the Donetsk basin are more difficult in comparison with other regions. The average depth of field development exceeds 700 m, and 30% of mines operate at a depth of 1000 -1400 m. Approximately 80% are gas mines, 60% are dangerous due to coal dust explosions, and 50% are dangerous due to sudden emissions and rock strikes [1,2]. So in-seam drivage with a roadheader in emission-hazardous coal seams and rocks, as well as in zones of mining and geological disturbances, development of emission-hazardous formations by workings in mines of Ukraine refer to mining operations in extremely difficult conditions.…”

“…It is necessary to recognize the difficulties in drilling boreholes and wells in any coal seams and rocks, especially when forming workings with a cross-sectional area of more than 20 m 2 . To make such workings, it is necessary to drill at least 65 -70 holes to a depth of 2.5 m [2]. This problem can be solved only by using a device for mechanized drilling of boreholes or wells (drilling machine) in the emission-hazardous coal seam during underground development galleries drivage with a roadheader with an operation device on a telescopic boom, which can drill in any location of the mine face surface of the working and any direction relative to its axis.…”