Effect of dip on pillar strength
© The Southern African Institute of Mining and Metallurgy, 2018. Pillars are commonly left in underground mining, either for secondary extraction after the primary stopes have been filled or to maintain the overall macro-stability of the mine during its useful life by supporting the overburden. The...
| Main Authors: | , |
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| Format: | Journal Article |
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Southern African Institute of Mining and Metallurgy
2018
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| Online Access: | http://hdl.handle.net/20.500.11937/72920 |
| _version_ | 1848762877500981248 |
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| author | Jessu, Kashi Spearing, Sam |
| author_facet | Jessu, Kashi Spearing, Sam |
| author_sort | Jessu, Kashi |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | © The Southern African Institute of Mining and Metallurgy, 2018. Pillars are commonly left in underground mining, either for secondary extraction after the primary stopes have been filled or to maintain the overall macro-stability of the mine during its useful life by supporting the overburden. The dip, dimensions, and geological features of an orebody determine the mining method used. If pillars are used, the orientation of pillars can vary from horizontal to vertical and anything in-between. The pillars left in underground mines can be loaded axially or obliquely (axial and shear components) depending on their orientation and that of the field stresses. Empirically established methods or numerical modelling are used to design mine pillars. We conducted studies on square and rectangular pillars under normal and oblique loading. The strengths of the horizontal pillars were calibrated to the Lunder and Pakalnis pillar strength, while the strength of the inclined pillars was obtained in reference to the horizontal pillar performance. The failure modes are described for inclined pillars at different width to height ratios. Brittle failure was determined to be the dominant failure mode in the inclined pillars. Rectangular pillars are beneficial only when the length is increased along the dip at higher inclinations and with W/H ratios greater than 1.5. |
| first_indexed | 2025-11-14T10:54:33Z |
| format | Journal Article |
| id | curtin-20.500.11937-72920 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T10:54:33Z |
| publishDate | 2018 |
| publisher | Southern African Institute of Mining and Metallurgy |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-729202019-04-02T07:44:24Z Effect of dip on pillar strength Jessu, Kashi Spearing, Sam © The Southern African Institute of Mining and Metallurgy, 2018. Pillars are commonly left in underground mining, either for secondary extraction after the primary stopes have been filled or to maintain the overall macro-stability of the mine during its useful life by supporting the overburden. The dip, dimensions, and geological features of an orebody determine the mining method used. If pillars are used, the orientation of pillars can vary from horizontal to vertical and anything in-between. The pillars left in underground mines can be loaded axially or obliquely (axial and shear components) depending on their orientation and that of the field stresses. Empirically established methods or numerical modelling are used to design mine pillars. We conducted studies on square and rectangular pillars under normal and oblique loading. The strengths of the horizontal pillars were calibrated to the Lunder and Pakalnis pillar strength, while the strength of the inclined pillars was obtained in reference to the horizontal pillar performance. The failure modes are described for inclined pillars at different width to height ratios. Brittle failure was determined to be the dominant failure mode in the inclined pillars. Rectangular pillars are beneficial only when the length is increased along the dip at higher inclinations and with W/H ratios greater than 1.5. 2018 Journal Article http://hdl.handle.net/20.500.11937/72920 10.17159/2411-9717/2018/v118n7a10 http://creativecommons.org/licenses/by/4.0/ Southern African Institute of Mining and Metallurgy fulltext |
| spellingShingle | Jessu, Kashi Spearing, Sam Effect of dip on pillar strength |
| title | Effect of dip on pillar strength |
| title_full | Effect of dip on pillar strength |
| title_fullStr | Effect of dip on pillar strength |
| title_full_unstemmed | Effect of dip on pillar strength |
| title_short | Effect of dip on pillar strength |
| title_sort | effect of dip on pillar strength |
| url | http://hdl.handle.net/20.500.11937/72920 |