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Structural mechanisms contributing to large-scale hangingwall instabilities on the UG2 reef horizon
Dissertation (Msc)--University of Pretoria, 2019.
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University of Pretoria
2019
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| _version_ | 1867613664380452864 |
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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 | © 2019 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 (Msc)--University of Pretoria, 2019. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/72736 |
| institution | University of Pretoria (South Africa) |
| last_indexed | 2026-06-10T12:39:44.581Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2019 |
| publishDateRange | 2019 |
| publishDateSort | 2019 |
| 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:2263/72736 Structural mechanisms contributing to large-scale hangingwall instabilities on the UG2 reef horizon Malan, D.F. u28109105@tuks.co.za Hartzenberg, Alida Gertruida UCTD Hangingwall instabilities UG2 reef Structural mechanisms Rock mechanics Mining geotechnics 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-11 SDG-11: Sustainable cities and communities Engineering, built environment and information technology theses SDG-12 SDG-12: Responsible consumption and production Dissertation (Msc)--University of Pretoria, 2019. Structural complexities, including regional geologic structures, low-angle structures, ramp structures and alteration zones contribute towards large-scale hangingwall or structural (pillar) instabilities experienced in many UG2 chromitite mines. The associated anomalous behaviour of the rock mass caused by these structures may result in significant ore reserve write-offs. The inability of technical and underground mining personnel to pro-actively identify and treat these geologic structures and associated failure mechanisms has resulted in ongoing instabilities experienced in many mines. Anomalous behaviour is mostly as a result of the exposure of numerous low-angle structures on various scales, commonly known as ‘doming’. These low-angle structures are treated simplistically or go unnoticed. Also, the presence of pegmatite veins, which is a common joint characteristic, causes problems and is generally ignored as the potential for instability. Furthermore, the presence of alteration zones is typically unnoticed as it is not common. The exposure of these prominent structures or a combination of these structures can impact on the exposed hangingwall conditions, panel span, support- and pillar behaviour. In some instances the impact have resulted in multiple fatalities and total mine closure. Case studies were conducted by the author at the Lonmin Marikana Operations where large-scale instabilities have been experienced. These findings were related to other similar study sites in the Bushveld Complex and the Great Dyke in Zimbabwe. The investigations confirmed some of the findings made by previous studies. However, new information gained from this study provided an improved understanding of the formation, interaction and potential instabilities if these structures are exposed by mining. The formation of the Bushveld Complex and geologic structures contributed to the anomalous conditions experienced in some underground mine workings. With the application of a new technology by the author (a sub-surface profiler), for the first time, the presence and location of these anomalous structures could be verified in the hangingwall. This contributes to an improvement in the spatial interpretation of these structures and confirmed that it should be considered in the mining strategy and support design processes. The learnings from the study will assist with the early detection of specific structural conditions which may contribute to the mitigation of potentially unstable conditions. Suitable remedial strategies were developed by the author from the site investigations and are discussed in detail. This includes the application of preferred mining layouts, mining direction, spans and support strategies where these structures are present. This work may significantly reduce the risk of large-scale instabilities and is therefore considered a significant contribution towards improving safety and the understanding of these anomalous structures at the mines in the Bushveld Complex. om2025 Mining Engineering MSc Unrestricted SDG-04: Quality education SDG-08: Decent work and economic growth SDG-09: Industry, innovation and infrastructure SDG-11: Sustainable cities and communities SDG-12: Responsible consumption and production 2019-12-13T08:07:54Z 2019-12-13T08:07:54Z 2019/09/02 2019 Dissertation Hartzenberg, AG 2019, Structural mechanisms contributing to large-scale hangingwall instabilities on the UG2 reef horizon, MSc Dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/72736> S2019 http://hdl.handle.net/2263/72736 © 2019 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 Hangingwall instabilities UG2 reef Structural mechanisms Rock mechanics Mining geotechnics 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-11 SDG-11: Sustainable cities and communities Engineering, built environment and information technology theses SDG-12 SDG-12: Responsible consumption and production Structural mechanisms contributing to large-scale hangingwall instabilities on the UG2 reef horizon |
| title | Structural mechanisms contributing to large-scale hangingwall instabilities on the UG2 reef horizon |
| title_full | Structural mechanisms contributing to large-scale hangingwall instabilities on the UG2 reef horizon |
| title_fullStr | Structural mechanisms contributing to large-scale hangingwall instabilities on the UG2 reef horizon |
| title_full_unstemmed | Structural mechanisms contributing to large-scale hangingwall instabilities on the UG2 reef horizon |
| title_short | Structural mechanisms contributing to large-scale hangingwall instabilities on the UG2 reef horizon |
| title_sort | structural mechanisms contributing to large scale hangingwall instabilities on the ug2 reef horizon |
| topic | UCTD Hangingwall instabilities UG2 reef Structural mechanisms Rock mechanics Mining geotechnics 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-11 SDG-11: Sustainable cities and communities Engineering, built environment and information technology theses SDG-12 SDG-12: Responsible consumption and production |
| url | http://hdl.handle.net/2263/72736 |