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Substantiation of pillar parameters in mining of inclined coal seams in Quang Ninh Province, Vietnam

https://doi.org/10.17073/2500-0632-2022-2-93-99

Abstract

Design and operation of auxiliary underground workings in coal mines involves substantiation of parameters of coal pillars and requires development of new approaches to substantiate their geometrics. On the one hand, sufficient stability of a “rock mass – working – coal pillar” system should be ensured. On the other hand, the parameters of “frozen” coal reserves in the pillars should be justified. The joint solution of these two problems requires accurate forecasting based on modern digital models of a rock mass. In this study, a model of rock mass and mine workings with different dimensions of a coal pillar is presented with the use of Flac3D software. The simulation findings showed that when developing sloping coal seams, the volume of coal extraction in a longwall has an effect on the stress-strain state of the enclosing rock mass. During the study different factors having effect on geometrics of a coal pillar were analyzed, and their influence on the field of stresses and shear of inclined layers in a rock mass was studied, and the size of the plastic deformation zone around an auxiliary mine working was also determined. The study findings are also of practical importance in terms of substantiating the parameters of a working support design. The size of coal pillar is also connected with the support type. It should be taken into account that bolts should be of sufficient length to ensure firm fixing and located in the zone of intact rocks. The research showed that a coal pillar should be 10 to 15 m wide in order to ensure optimal mining conditions and safety.

About the Authors

V. N. Nguyen
Hanoi University of Mining and Geology
Viet Nam

Viet Nghia Nguyen – Lecturer

Scopus ID 57204141788

Hanoi



T. N. Pham
Hanoi University of Mining and Geology
Viet Nam

Thi Nhan Pham – Lecture

Scopus ID 57369754200

Hanoi



P. Osinski
Warsaw University of Life Science
Poland

Piotr Osinski – Assistant, Department of Geotechnical Engineering

Scopus ID 55929586000

ResearcherID N-5911-2015

Warsaw



T. C. Nguyen
Hanoi University of Mining and Geology
Viet Nam

Thi Cuc Nguyen – Lecturer

Scopus ID 57450931300

Hanoi



L. H. Trinh
Le Quy Don Technical University
Viet Nam

Le Hung Trinh – Lecturer

Scopus ID 57035066200

Hanoi



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Review

For citations:


Nguyen V.N., Pham T.N., Osinski P., Nguyen T.C., Trinh L.H. Substantiation of pillar parameters in mining of inclined coal seams in Quang Ninh Province, Vietnam. Mining Science and Technology (Russia). 2022;7(2):93-99. https://doi.org/10.17073/2500-0632-2022-2-93-99

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