ANALYSIS OF COAL SEAM PERMEABILITY AROUND THE EDGES VERSUSSTRESS-STRAIN STATE OF ROCK MASS

The article presents the research results on distribution of stresses, strains and permeability around the edges of coal seam nearby longwall face. This subject is of concern currently as interacting processes of gas flow and deformation in methane-bearing coal seams during underground mining are insufficiently studied. The problem of geomechanical and gas-flow control in rock mass consists in the integration of rock mass stability around underground openings and coal seam methane drainage. Justification of drainage parameters at faces needs theoretical generalization of relationships between coal seam permeability and coal seam–enclosing rock mass stress state in specific geological and geotechnical conditions. The subject of the study is the interacting geomechanical and gas-flow processes in coal seam. The study aims to reveal regular patterns in distribution of coal permeability coefficient around the edges of coal seam with regard to effect of alternating elastic and elastoplastic horizontal and vertical strains in coal. The finite element-based solution of 2D problem on deformable solid uses the input data in the form of the diagrams of elastic and elastoplastic strains obtained in the lab-scale tests of coal and rock specimens. From the elastoplastic problem solution, the relationships of permeability, stresses and strains in coal are established. It is found that coal permeability at the edges of seam is considerably influenced both by horizontal and vertical strains. The new research findings are the revealed patterns of stress and strain distributions in coal seam nearby longwall face, as well as the influence of these parameters on permeability and methane pressure in coal at the edges of seam.


For citation: Shiryaev S. N., Cherepov A. A., Petrova O. A. Analysis of coal seam permeability around the edges versus stress–strain state of rock mass. MIAB. Mining Inf. Anal. Bull. 2019;(9):62-71. [In Russ]. DOI: 10.25018/0236-1493-2019-09-0-62-71.

Keywords

Methane-bearing coal seam, mine, longwall face, stresses, strains, permeability, elasticity theory, plasticity theory, coal strength, coal porosity.

Issue number: 9
Year: 2019
ISBN: 0236-1493
UDK: 622.817.47
DOI: 10.25018/0236-1493-2019-09-0-62-71
Authors: Shiryaev S. N., Cherepov A. A., Petrova O. A.

About authors: S.N. Shiryaev (1), First Deputy Technical Director, e-mail: Sergey.Shiryaev2@evraz.com, A.A. Cherepov (1), Technical Director, e-mail: Andrey.Cherepov@evraz.com, O.A. Petrova, Cand. Sci. (Eng.), Senior Researcher, Prokopievsk branch of Kuzbass State Technical University, 653033, Prokopyevsk, Russia, e-mail: ol_petrova@mail.ru, 1) LLC «Raspadskaya coal company», 654027, Novokuznetsk, Russia. Corresponding author: S.N. Shiryaev, e-mail: Sergey.Shiryaev2@evraz.com.

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