The Impact of Moisture Content on Outburst Hazard of Sandstones in Coal-Bearing Strata

  • Kostiantyn Andriiovych Bezruchko Institute of Geotechnical Mechanics named by N. Polja-kov of National Academy of Sciences of Ukraine
Keywords: Rock and gas outbursts, Prognosis, Carboniferous sandstones, Moisture, Porosity


The article theorizes the impact of the quantitative moisture content in rocks with two main factors of outburst hazard – their physical and mechanical properties and the gas factor. The impact of natural humidity and reservoir properties of sandstones on the degree of their outburst hazard and the depth of outburst manifestation in coal mines of the Donetsk Basin (Ukraine) is researched. The exploration targets were outburst-prone sandstones of the Lower and Middle Carboniferous age of the coal-bearing strata of Donbas in Ukraine. Sandstones lay in zones of middle and late catagenesis, within the distribution of gas, fatty, and coking coals in the depth range of 700–1200 m. The author evaluated the absolute humidity (weight moisture indicator), relative humidity (water saturation or the degree of pore filling with moisture), and open porosity of researched sandstones. It has been established that the weight moisture/open porosity ratio determines the degree of outburst hazard of sandstones. This indicator is proposed as a prognostic criterion for determining the degree of outburst hazard of sandstones. A connection has also been established between the manifestation depth of sandstone and gas outbursts with their water and gas saturation. Based on determining the critical values for the degree of pore filling with moisture for fixed stratification depths, an evaluation method of outburst hazard is proposed. Testing the use of the proposed methods for determining the outburst hazard of rocks, considering the natural moisture of sandstones, in the mines of Donbas, fully confirmed their reliability, validity, and the possibility of practical application.


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