Krukovskyi O.P., Krukovska V.V., Usov O.O. Influence of coal seam treatment by water and antipyrogenes on formation of stress fields around mine working

Details
Parent Category: Geo-Technical Mechanics, 2020
Category: Geo-Technical Mechanics, 2020, № 150

Geoteh. meh. 2020, 150, 116-126

https://doi.org/10.15407/geotm2020.150.116

 

INFLUENCE OF COAL SEAM TREATMENT BY WATER AND ANTIPYROGENES ON FORMATION OF STRESS FIELDS AROUND MINE WORKING

1Krukovskyi O.P.,1Krukovska V.V., 1Usov O.O.

 Institute of Geotechnical Mechanics named by N. Poliakov of National Academy of Sciences of Ukraine

UDC 539.32:622.831.3

Language: Russian

Annotation.

The injection of aqueous solutions of antipyrogenes into a coal seam prone to self-ignition is traditionally used to reduce risk of endogenous fires. It is known that the saturation of coal with water significantly changes its mechanical characteristics and leads to the unloading of the coal seam near the mine workings. Therefore, a quantitative assessment of changes in geomechanical parameters in the marginal zone before and after treatment of the coal seam with water is a strong business case. Knowledge of the dynamics of the stress field formation around the mine working will allow to improve technology of treating the coal seam with antipyrogens. The goal of the work is to study changes in the stress state of the face zone of the coal seam at various rates of its humidity by using numerical simulation methods. The problem is solved in an elastoplastic setting. For mathematical description of the process of transition of rocks into a disturbed state, the Coulomb-Moore strength condition is applied. The finite element method is used for solving the problem. The algorithm allows to track the change in the stress state depending on the time passed after the last cycle of the rock mass excavation.

Distribution of the values of the principal stress tensor components, geomechanical parameters characterizing different components of the stress field and unloading of rocks from rock pressure, as well as zones of inelastic deformations were obtained as a result of solving the problem. The calculated data showed that over time, the values of the considered geomechanical parameters in the face zone of the coal seam gradually increase. The distance from the face to the zone of bearing pressure (maximum stress) also increases with time. In a wetter coal, the growth of the bearing pressure zone slows down. At the initial periods of time after the cycle of rock mass extraction, effect of softening of coal with higher level of humidity is noticeable, which is manifested in increase of zone of inelastic deformation. After treatment with water, the magnitude of the maximum stresses and the difference between the maximum and minimum components of the stress field are reduced (about 1.5 times).

Keywords:

injection of aqueous solutions, antipyrogenes, coal seam, stress state, numerical simulation.

References

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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. Poliakov of National Academy of Sciences of Ukraine (IGTM, NAS of Ukraine), Dnipro, Ukraine,  This email address is being protected from spambots. You need JavaScript enabled to view it. .

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

Usov Oleh Oleksandrovych, Candidate of Technical Sciences (Ph, D), Senior Researcher of Department of Rocks Mechanics, Institute of Geotechnical Mechanics named by N. Poliakov of National Academy of Sciences of Ukraine (IGTM, NAS of Ukraine), Dnipro, Ukraine.