INTERDEPENDENCIES BETWEEN GEOMECHANICAL PROCESSES AND EMISSION OF METHANE AND RADON DECAY PRODUCTS INTO UNDERGROUND WORKINGS OF THE COAL MINES

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Parent Category: Geo-Technical Mechanics, 2014

Category: Geo-Technical Mechanics, 2014, Issue 114

UDC 622.831.312 : 622.817

INTERDEPENDENCIES BETWEEN GEOMECHANICAL PROCESSES AND EMISSION OF METHANE AND RADON DECAY PRODUCTS INTO UNDERGROUND WORKINGS OF THE COAL MINES

Bulat, AF; Slashchov, IN; Slashchovа, EA

Authors:

A. F. Bulat, Acad. NASU, D. Sc. (Tech.), Professor,

I.N. Slashchov, Ph.D. (Tech.), Senior Researcher,

E.A. Slashchovа, Ph.D. (Tech.), Senior Researcher

(IGTM NAS of Ukraine)

Abstract.

Purpose of this article is to specify conditions for joint filtration of methane and radon decay products and changes of their physical parameter in the workings of coal mines.

A method for numerical simulation of methane transfer and radon isotope from areas with high rock pressure through the cracks in zones with rock shift and stretching into the mine workings was proposed. To describe of gas transfer processes, an integrated form of the Darcy law for a case of radial steady flow was used. Interdependencies between methane and radon isotope contents in the atmosphere of mine workings were investigated in-situ.

The author proposes to assess conditions for the joint methane transfer and radon aerosol through the rocks with the help of minimum principal strains of elements in the geomechanical model and deformation tensor deviator which define compression, shift and stretching parameters of the pore-fractured space. It is for the first time when specific physical features of joint emission of methane and radon decay products into the mine working are disclosed: concentration of the Po²¹⁸ α-radiation increases depending on the distance to the development heading and its Po²¹⁸ intensity is 2-4 times higher than intensity of α-radiation of Pb²¹⁴ and Bi²¹⁴ isotopes; there is a stable interdependency between dynamics of changes in methane concentration and reduced concentration of radon decay products when deviation of concentration change is within ± 20 % from the mean value, and abrupt peaks of concentration changing above 40 % can be explained by different sources of formation of methane and radon-aerosol flows and different rates of their transfer through the pores and cracks in tectonically disturbed zones of the rock massif; emission of the Po²¹⁸ radionuclide is weakly connected with radiation of the Pb²¹⁴ and Bi²¹⁴ α-particles, and, conversely, between Pb²¹⁴ and Bi²¹⁴ emissions with a longer half-life a strong interdependency is observed. These interdependencies can be a basis for designing new methods for prediction manifestations of geomechanical and gasdynamic processes.

Keywords:

Methane Filtering, Radon Decay Products, Geomechanical Processes, Gasdynamic Processes, Modeling of Rock Massif, Prediction of Dangerous Phenomena

References:

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About the authors:

Bulat Anatoly Fedorovich., Academician of the National Academy of Science of Ukraine, Doctor of Technical Sciences (D. Sc), Professor, Director of the Institute, M.S. Polyakov Institute of Geotechnical Mechanics under the National Academy of Science of Ukraine (IGTM, NASU), Dnepropetrovsk, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.

Slashchov Igor Nikolaevich, Candidate of Technical Sciences (Ph.D), Senior Researcher, Senior Researcher in Department of Mineral Mining at Great Depths, M.S. Polyakov Institute of Geotechnical Mechanics under the National Academy of Science of Ukraine (IGTM, NASU), Dnepropetrovsk, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.

Slashchovа Yelena Anatolyevna, Candidate of Technical Sciences (Ph.D), Senior Researcher, Senior Researcher in Department of Mineral Mining at Great Depths, M.S. Polyakov Institute of Geotechnical Mechanics under the National Academy of Science of Ukraine (IGTM, NASU), Dnepropetrovsk, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.

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