Krukovskyi O.P., Minieiev S.P., Krukovska V.V., Belikov I.B. The influence of working seam thickness on permeability of barrier pillars near isolated fire sections

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Parent Category: Geo-Technical Mechanics, 2021

Category: Geo-Technical Mechanics, 2021, Issue 158

Geoteh. meh. 2021, 158, 3-15

https://doi.org/10.15407/geotm2021.158.003

 

THE INFLUENCE OF WORKING SEAM THICKNESS ON PERMEABILITY OF BARRIER PILLARS NEAR ISOLATED FIRE SECTIONS

¹Krukovskyi O.P., ¹Minieіev S.P., ¹Krukovska V.V., ²Belikov I.B.

¹Institute of Geotechnical Mechanics named by N. Poljakov of NAS of Ukraine, ²Central Staff of the State Militarized Mine Rescue Service of Ukraine

UDC 622.411.332.023.623:622.83

Language: English

Abstract. The study of filtration permeability of the barrier pillar between the isolated fire section and the worked longwall ventilation drift was completed using the mathematical model developed by the authors for coupled processes of rock deformation and gas filtration. The problem is solved involving a finite element method implemented in the author's programme. When solving, the parameters of width of the barrier pillar and thickness of the mined coal seam were varied. The article presents the results of calculating the values of geomechanical parameters, permeability coefficients and gas pressure in the filtration area.
It is shown that with an increase in thickness of the coal seam, intensity of the crack formation process increases in the barrier pillar. With small pillar width, the coal seam along its entire length is in a disturbed state, as well as the rocks of its roof and soil. The filtration areas around the worked longwall ventilation drift and the isolated conveyor drift are connected both along the coal seam and along the host rocks. This means that at a certain value of the pressure drop, filtration of fire gases into the mine workings of the worked excavation section is possible. With a greater width of the pillar, between disturbed rocks around the mine workings of the worked section and isolated fire one, there is a barrier made of undisturbed rocks. That impermeable barrier prevents gas filtration from one mine workings to another. Its width decreases with an increase in the thickness of the coal seam.
Based on the results of calculating gas pressure, it is shown that methane from the coal seam moves into atmosphere of the mine workings, where gas pressure has lower values. At the same time, for the accepted conditions, with a pillar width of 20 m and a seam thickness of 0.4 m, gas is filtered from the mine workings of isolated fire section into the adjacent excavation section along the disturbed rocks of the seam roof. In the rest of the cases, the areas of low pressure around the mine workings are separated by zones of higher pressure, exceeding pressure of fire gases in the isolated section. Filtration of fire gases into atmosphere of the worked excavation section is impossible under such conditions.
Keywords: mining safety, barrier pillar, isolated fire section, deformation of the rocks, gas filtration, seam thickness.

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About the authors:

Krukovskyi Oleksandr Petrovych, Corresponding Member of NAS of Ukraine, Doctor of Technical Sciences (D. Sc), Deputy Director of the institute, Institute of Geotechnical Mechanics named by N. Poljakov of the National Academy of Sciences of Ukraine (IGTM of NAS of Ukraine), Dnipro, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.

Minіeiev Serhii Pavlovych, Doctor of Technical Sciences (D.Sc.), Professor, Head of the Department of Pressure Dynamics Control in Rocks, Institute of Geotechnical Mechanics named by N. Poljakov of the National Academy of Sciences of Ukraine (IGTM of NAS of Ukraine), Dnipro, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.

Krukovska Viktoriia Viktorivna, Doctor of Technical Sciences (D. Sc), Senior Researcher, Senior Researcher in Department of Pressure Dynamics Control in Rocks, Institute of Geotechnical Mechanics named by N. Poljakov of the National Academy of Sciences of Ukraine (IGTM of NAS of Ukraine), Dnipro, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.

Belikov Ihor Borysovych, Master of Science, First Deputy Chief of the Central Staff of the SMMSS of Ukraine, Kramotorsk, Ukraine.

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