Feldman E.P., Kalugina N.O., Chesnokova O.V. Influence of gas filtration on main crack development during stationary face drivage

Geoteh. meh. 2018, 138, 212-217

DOI: https://doi.org/10.15407/geotm2018.01.212

Influence of gas filtration on main crack development during stationary face drivage

Feldman E.P., Kalugina N.O., Chesnokova O.V.

Authors:

Feldman E.P, Doctor of Physical and Mathematical Sciences, Professor, Chief Researcher (Institute of Physics and Industry, National Academy of Sciences of Ukraine)

Kalugina N.A., Dr. Tech. Sci., Senior Researcher, Scientific Secretary (Institute of State Public Accountants of the Ukrainian Academy of Sciences)

Chesnokova O.V. , Researcher (Institute of Physics and Industry, National Academy of Sciences of Ukraine)

UDC 622.831: 622.537.86

Language: Russian

Abstract.

On the basis of comparison of kinetics of two physical processes occurring simultaneously during development of gas-coal deposits – coal seam discharge from rock pressure and methane filtration in coal - a criterion was established for unleashing spontaneous destruction of bottom-hole section in the gas-saturated coal bed during stationary face driving.

During the face drivage, stresses, which compress cracks in the coal seam, gradually decrease (unloading of the seam) and, hence, contribute to further development of cracks. Simultaneously, gas pressure in the cavities of the cracks is released due to the gas escaping into the goaf, and development of the cracks stops. Therefore, result of the crack development depends on one of these two competing processes, which will develop faster. By using an idea of the «mean field approximation», it is possible to consider only one crack - main crack, which effects on parameters of the surrounding «thermostat» - instead of the system of cracks. The ratio found assumes, as necessary condition, usage of the Griffith criterion for material rupture by the gas-saturated crack. The criterion makes it possible to understand role of the coal seam physical parameters - rock pressure, gas pressure, elastic moduli, fracturing, adhesive forces of material, methane filtration in coal, and technological parameters of mining operations - in order to provide safety-by-gas-outburst conditions for coal deposit development.

A diagram of dependence between the face driving rate and gas filtration rate was constructed, which indicates hazardous and safety by gas outbursts sectors. The diagram allows to choose economically expedient, and, at the same time, safety rate of mining the coal seam with taking into account its physical and chemical properties and geotechnological working conditions. Parameters of material in the resulted equation were determined by laboratory and field experiments, including those carried out at the Institute for Physics of Mining Processes of the National Academy of Sciences of Ukraine.

Keywords:

 main crack, coal bed, gas, filtration, pressure, discharge.

References:

  1. Shevelev, G.A. (1989), Dinamika vybrosov uglya, porody i gaza [The dynamics of coal, rock and gas emissions], Naukova dumka, Kyiv, Ukraine.
  2. Zhi, S. and Elsworth, D. (2016), The role of gas desorption on gas outbursts in un-derground mining of coal, Geomech. Geophys. Geo-energ. Geo-resour., V. 2, p. 151-171.
    https://doi.org/10.1007/s40948-016-0026-2
  3. Feldman, E.P., Kalugina, N.A. and Melnik, T.N. (2017), Rol razgruzki i filtratsii gaza v protsesse razvitiya magistralnyih treschin v ugolnom plaste [The role of gas unloading and filtration in the process of development of main cracks in a coal seam], Applied mechanics and technical physics, V. 58(1), p. 155-164.
    https://doi.org/10.1134/S0021894417010175
  4. Feldman, E.P., Kalugina, N.A. and Chesnokova, O.V. (2017), Evolyutsiya treschin v kraevoy chasti ugolnogo plasta pri ego statsionarnoy otrabotke. Min. miner. depos., 11(2): 41-45.
    https://doi.org/10.15407/mining11.02.041
  5. Feldman, E.P., Kalugina, N.A. and Chesnokova, O.V. (2017), Change in gas pressure in the vicinity of the main crack with uniform movement of the face, Physical and technical problems of mountain production, V. 19.

About the authors

Feldman Eduard Petrovich, Doctor of Physical and Mathematical Sciences, Professor, State Scientific Worker, Department of Physics of Coal and Rock, Institute for Physics of Mining Processes of the National Academy of Sciences of Ukraine, Dnipro, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.

Kalugina Nadiia Oleksandrivna, Doctor of Engineering Sciences, Senior Researcher, Scientific Secretary of the Institute for Physics of Mining Processes of the National Academy of Sciences of Ukraine, Dnipro, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.

Chesnokova Oksana Vitalievna, Scientific employee, Department of Physics of Coal and Rock, Institute for Physics of Mining Processes of the National Academy of Sciences of Ukraine, Dnipro, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.

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