Krukovska V.V. Formation of unloaded zone in the mine face depending on the face advancing rate

Geoteh. meh. 2018, 138, 108-114

DOI: https://doi.org/10.15407/geotm2018.01.108

Formation of unloaded zone in the mine face depending on the face advancing rate

Krukovska V.V.

Author:

Krukovska V V., Doctor of Technical Sciences (D. Sc), Senior Researcher (IGTM NASU)

UDC 622.267.5

Language:Russian

Abstract.

As practice shows, risk of sudden coal and gas outbursts increases at high rate of the face advancing. It is possible to prevent gas dynamic processes if to choose by calculation method such rate of advancing, at which depth of unloaded zone remains at a safe level. Therefore, performing of correct calculations with taking into account coal-and-rock physical and mechanical properties, parameters of mine tunnel and technology of mining is of great importance.

In this paper, mathematical and numerical simulation of coupled processes of coal-and-rock massif deformation and methane filtration was performed with taking into account their mutual influence and changes on a timeline. Condition for interconnection between geomechanical and filtration processes is dependence between permeability coefficients and stress tensor components. Feedback is realized through forces caused by gas pressure taken into account in calculation of total force acting on each point of the solid. The problem is solved through plasto-elastic condition. The Mohr-Coulomb strength condition is applied for mathematical description of the process of rocks transition into disturbed state.

The problem of dimensions of unloaded region changing on a timeline in the mine face was solved by the finite element method, which took into account physical and mechanical properties of the coal-rock mass and parameters of the mine working. Distribution of values of geomechanical parameter Q*, which characterizes the stress field, at various time points after coal-and-rock extraction were obtained. Dependence of unloaded zone depth on the rate of the face advancing was determined. It is shown that with increase of advancing rate from 1 m/day up to 8 m/day depth of the unloaded area in the mine face is reduced by 3,2-3,7 times.

Keywords:

deformation of the gas-saturated massif, rate of the face advancing, prevention of gas dynamic processes.

References:

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https://doi.org/10.1016/S1365-1609(97)00056-7

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About the authors

Krukovska Victoriya 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. Polyakov of National Academy of Science of Ukraine (IGTM NASU), Dnipro, Ukraine, This email address is being protected from spambots. You need JavaScript enabled to view it.

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