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The effect of shear stresses on pillar strength
Dissertation (MEng)--University of Pretoria, 2015.
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| Format: | Thesis |
| Language: | English |
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University of Pretoria
2015
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| _version_ | 1867613544077328384 |
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| access_status_str | Open Access |
| author2 | Malan, D.F. |
| author_browse | Malan, D.F. |
| author_facet | Malan, D.F. |
| collection | Thesis |
| dc_rights_str_mv | © 2015 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MEng)--University of Pretoria, 2015. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/50681 |
| institution | University of Pretoria (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:37:49.734Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2015 |
| publishDateRange | 2015 |
| publishDateSort | 2015 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/50681 The effect of shear stresses on pillar strength Malan, D.F. jannie.maritz@up.ac.za Napier, J.A.L. Maritz, Jan Abram UCTD Shear stresses Pillar strength Pillar design optimization Rock mechanics Mine safety Engineering, built environment and information technology theses SDG-04 SDG-04: Quality education Engineering, built environment and information technology theses SDG-08 SDG-08: Decent work and economic growth Engineering, built environment and information technology theses SDG-09 SDG-09: Industry, innovation and infrastructure Engineering, built environment and information technology theses SDG-12 SDG-12: Responsible consumption and production Dissertation (MEng)--University of Pretoria, 2015. In mining, the loading environment on pillars is highly complex with combinations of normal and shear stresses. It is also understood that with an active and working face, constant redistribution of stresses will occur to maintain stress equilibrium. A rock sample subjected to uniaxial loading conditions can fail in either indirect tension or shear. A pillar in the mining environment would react in much the same way. However, as “confinement” is created at the pillar and hanging wall or footwall contacts, shear failure is commonly observed in failed pillars. A number of theories and equations have been derived trying to correctly calculate pillar strength in an underground design. These early attempts argued that the strength is only governed by the width of the pillar in relation to the mining height as well as a certain pillar “strength” constant (K-value). Both the coal and hard rock industries have adopted this design methodology for determining pillar sizes, all with relatively good success. Numerical analysis has shown that complex stress interaction occur between irregular shape pillars when not superimposed, highlighting the fact that superimposing of pillars should be treated with caution. As the stress environment changes, so does the loading on the pillar with preliminary results showing that the strength of the pillar will also be affected in the presence of shear stress. The research presented in this document shows that loading conditions that may affect pillar strength should be considered and detailed and special treatment should be given during the design in cases where shear loading may exist. tm2015 om2025 Mining Engineering MEng Unrestricted SDG-04: Quality education SDG-08: Decent work and economic growth SDG-09: Industry, innovation and infrastructure SDG-12: Responsible consumption and production 2015-11-25T09:47:14Z 2015-11-25T09:47:14Z 2015/09/01 2015 Dissertation Maritz, JA 2015, The effect of shear stresses on pillar strength, MEng Dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/50681> S2015 http://hdl.handle.net/2263/50681 en © 2015 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | UCTD Shear stresses Pillar strength Pillar design optimization Rock mechanics Mine safety Engineering, built environment and information technology theses SDG-04 SDG-04: Quality education Engineering, built environment and information technology theses SDG-08 SDG-08: Decent work and economic growth Engineering, built environment and information technology theses SDG-09 SDG-09: Industry, innovation and infrastructure Engineering, built environment and information technology theses SDG-12 SDG-12: Responsible consumption and production The effect of shear stresses on pillar strength |
| title | The effect of shear stresses on pillar strength |
| title_full | The effect of shear stresses on pillar strength |
| title_fullStr | The effect of shear stresses on pillar strength |
| title_full_unstemmed | The effect of shear stresses on pillar strength |
| title_short | The effect of shear stresses on pillar strength |
| title_sort | effect of shear stresses on pillar strength |
| topic | UCTD Shear stresses Pillar strength Pillar design optimization Rock mechanics Mine safety Engineering, built environment and information technology theses SDG-04 SDG-04: Quality education Engineering, built environment and information technology theses SDG-08 SDG-08: Decent work and economic growth Engineering, built environment and information technology theses SDG-09 SDG-09: Industry, innovation and infrastructure Engineering, built environment and information technology theses SDG-12 SDG-12: Responsible consumption and production |
| url | http://hdl.handle.net/2263/50681 |