Influence of Driving Direction on the Stability of a Group of Headings Located in a Field of High Horizontal Stresses in the Polish Underground Copper Mines

This paper investigates the problem of stability in a group of headings driven in high horizontal stress fields in the copper ore mines of the Legnica-Glogow Copper Belt (LGCB). The headings are protected with the roof bolting system. This problem is of high importance due to special safety regulati...

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Main Authors: Karolina Adach-Pawelus, Daniel Pawelus
Format: Article
Language:English
Published: MDPI AG 2021-09-01
Series:Energies
Subjects:
Online Access:https://www.mdpi.com/1996-1073/14/18/5955
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author Karolina Adach-Pawelus
Daniel Pawelus
author_facet Karolina Adach-Pawelus
Daniel Pawelus
author_sort Karolina Adach-Pawelus
collection DOAJ
description This paper investigates the problem of stability in a group of headings driven in high horizontal stress fields in the copper ore mines of the Legnica-Glogow Copper Belt (LGCB). The headings are protected with the roof bolting system. This problem is of high importance due to special safety regulations which apply in mining workings serving as airways and haulageways. The analysis was performed for a group of four headings driven in the geological and mining conditions of the Polkowice-Sieroszowice mine. The stability of the headings was evaluated with the use of Finite Element Method (FEM). The parameters of the rocks used in the numerical modeling have been determined on the basis of the Hoek–Brown classification, with the use of the RocLab 1.0 software. The parameters of the stress field have been identified on the basis of in situ measurements, which were performed in the Polkowice-Sieroszowice mine in 2012. The measurements were carried out with the use of the overcoring method, which is a stress relief method. A CSIRO HI probe was used as the measuring device. The tests were carried out on three measuring points, on which six successful tests were performed. The measurements confirmed the presence of high horizontal stresses in the rock mass. Numerical modeling was performed using the Phase2 v.8.0 software, in a triaxial stress state and in a plane strain state. The rock mass was described with an elastic-plastic model with softening. Numerical analyses were based on the Mohr–Coulomb failure criterion. It was assumed that the optimal measure of the stability of the group of headings is the range of the formed zone of yielded rock mass in the excavation roof. Numerical simulations have shown that the direction of driving the headings in the field of increased horizontal stresses may be of key importance for the stability of the headings in LGOM mines. The greatest extent of the yielded rock mass zone in the excavation roof occurred when the group of headings was driven in the direction perpendicular to the direction of the maximum horizontal stress component <i>σ<sub>H</sub></i>. The obtained results served to provide an example of the application of a roof bolting system to protect headings driven in unfavorable conditions in a high horizontal stress field.
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spelling doaj.art-3f791d5c01aa4d9082c9a8061b4e9a0a2023-11-22T12:55:38ZengMDPI AGEnergies1996-10732021-09-011418595510.3390/en14185955Influence of Driving Direction on the Stability of a Group of Headings Located in a Field of High Horizontal Stresses in the Polish Underground Copper MinesKarolina Adach-Pawelus0Daniel Pawelus1Faculty of Geoengineering, Mining and Geology, Wroclaw University of Science and Technology, 50-370 Wroclaw, PolandFaculty of Geoengineering, Mining and Geology, Wroclaw University of Science and Technology, 50-370 Wroclaw, PolandThis paper investigates the problem of stability in a group of headings driven in high horizontal stress fields in the copper ore mines of the Legnica-Glogow Copper Belt (LGCB). The headings are protected with the roof bolting system. This problem is of high importance due to special safety regulations which apply in mining workings serving as airways and haulageways. The analysis was performed for a group of four headings driven in the geological and mining conditions of the Polkowice-Sieroszowice mine. The stability of the headings was evaluated with the use of Finite Element Method (FEM). The parameters of the rocks used in the numerical modeling have been determined on the basis of the Hoek–Brown classification, with the use of the RocLab 1.0 software. The parameters of the stress field have been identified on the basis of in situ measurements, which were performed in the Polkowice-Sieroszowice mine in 2012. The measurements were carried out with the use of the overcoring method, which is a stress relief method. A CSIRO HI probe was used as the measuring device. The tests were carried out on three measuring points, on which six successful tests were performed. The measurements confirmed the presence of high horizontal stresses in the rock mass. Numerical modeling was performed using the Phase2 v.8.0 software, in a triaxial stress state and in a plane strain state. The rock mass was described with an elastic-plastic model with softening. Numerical analyses were based on the Mohr–Coulomb failure criterion. It was assumed that the optimal measure of the stability of the group of headings is the range of the formed zone of yielded rock mass in the excavation roof. Numerical simulations have shown that the direction of driving the headings in the field of increased horizontal stresses may be of key importance for the stability of the headings in LGOM mines. The greatest extent of the yielded rock mass zone in the excavation roof occurred when the group of headings was driven in the direction perpendicular to the direction of the maximum horizontal stress component <i>σ<sub>H</sub></i>. The obtained results served to provide an example of the application of a roof bolting system to protect headings driven in unfavorable conditions in a high horizontal stress field.https://www.mdpi.com/1996-1073/14/18/5955numerical modelinghigh horizontal stressexcavations stability assessment
spellingShingle Karolina Adach-Pawelus
Daniel Pawelus
Influence of Driving Direction on the Stability of a Group of Headings Located in a Field of High Horizontal Stresses in the Polish Underground Copper Mines
Energies
numerical modeling
high horizontal stress
excavations stability assessment
title Influence of Driving Direction on the Stability of a Group of Headings Located in a Field of High Horizontal Stresses in the Polish Underground Copper Mines
title_full Influence of Driving Direction on the Stability of a Group of Headings Located in a Field of High Horizontal Stresses in the Polish Underground Copper Mines
title_fullStr Influence of Driving Direction on the Stability of a Group of Headings Located in a Field of High Horizontal Stresses in the Polish Underground Copper Mines
title_full_unstemmed Influence of Driving Direction on the Stability of a Group of Headings Located in a Field of High Horizontal Stresses in the Polish Underground Copper Mines
title_short Influence of Driving Direction on the Stability of a Group of Headings Located in a Field of High Horizontal Stresses in the Polish Underground Copper Mines
title_sort influence of driving direction on the stability of a group of headings located in a field of high horizontal stresses in the polish underground copper mines
topic numerical modeling
high horizontal stress
excavations stability assessment
url https://www.mdpi.com/1996-1073/14/18/5955
work_keys_str_mv AT karolinaadachpawelus influenceofdrivingdirectiononthestabilityofagroupofheadingslocatedinafieldofhighhorizontalstressesinthepolishundergroundcoppermines
AT danielpawelus influenceofdrivingdirectiononthestabilityofagroupofheadingslocatedinafieldofhighhorizontalstressesinthepolishundergroundcoppermines