dc.contributor.author |
Watson, BP
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dc.contributor.author |
Mosomane, SM
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dc.contributor.author |
Kuijpers, JS
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dc.contributor.author |
Roberts, David P
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dc.date.accessioned |
2009-07-23T14:06:01Z |
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dc.date.available |
2009-07-23T14:06:01Z |
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dc.date.issued |
2008-08 |
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dc.identifier.citation |
Watson BP, Mosomane SM, Kuijpers JS et al. 2008. Investigations into the residual strength of a 2.5 m wide Bushveld Merensky Reef crush pillar.The Journal of the Southern African Institute of Mining and Metallurgy, Vol. 108 pp, 473-480 |
en |
dc.identifier.issn |
0038-223X |
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dc.identifier.uri |
http://hdl.handle.net/10204/3510
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dc.description |
Copyright: 2008 Southern African Institute of Mining and Metallurgy |
en |
dc.description.abstract |
The first crush pillars on the Bushveld platinum mines were introduced at Union Section in 1978. Before the introduction of crush pillars, serious problems were experienced when stoping advanced to a point 30 m to 40 m on both sides of the centre gully. At least three to four stopes were collapsing per month. Increased incidence of bursting has been reported on some mines at deeper levels but most of these bursts occur in the back areas. Nevertheless, the incidence of bursting increases the risk of falls of ground in already dangerous areas, and the larger pillars decrease the extraction ratio. This paper describes the evaluation of stress measurements conducted in two boreholes over a crush pillar with dimensions 2.5 m x 4.0 m, and a height of 1.2 m.The residual strength of the crush pillar with a width of 2.5 m was determined from a series of strain measurements in two boreholes and a Boussinesq matrix inversion. The calculated peak and residual stresses of the pillar were surprisingly high at 280 MPa and 48 MPa respectively. These high stress conditions are suspected to be associated with the narrow pillar geometry on the up-dip side and the stiff loading conditions under which failure took place. In order to get a more realistic evaluation of residual strength, a series of such measurements is recommended to establish a range of residual strengths for narrow crush pillars. |
en |
dc.language.iso |
en |
en |
dc.publisher |
Southern African Institute of Mining and Metallurgy |
en |
dc.subject |
Micro-cracks |
en |
dc.subject |
Crush pillars |
en |
dc.subject |
Non-linear stress-strain |
en |
dc.subject |
Uniaxial compressive strength |
en |
dc.subject |
Pillar axis |
en |
dc.subject |
In situ measurement |
en |
dc.subject |
Borehole |
en |
dc.subject |
Bushveld Merensky Reef |
en |
dc.subject |
Stopes |
en |
dc.subject |
Stopes collapses |
en |
dc.subject |
Bursting |
en |
dc.subject |
Metallurgy |
en |
dc.subject |
Mining |
en |
dc.title |
Investigations into the residual strength of a 2.5 m wide Bushveld Merensky Reef crush pillar |
en |
dc.type |
Article |
en |
dc.identifier.apacitation |
Watson, B., Mosomane, S., Kuijpers, J., & Roberts, D. P. (2008). Investigations into the residual strength of a 2.5 m wide Bushveld Merensky Reef crush pillar. http://hdl.handle.net/10204/3510 |
en_ZA |
dc.identifier.chicagocitation |
Watson, BP, SM Mosomane, JS Kuijpers, and David P Roberts "Investigations into the residual strength of a 2.5 m wide Bushveld Merensky Reef crush pillar." (2008) http://hdl.handle.net/10204/3510 |
en_ZA |
dc.identifier.vancouvercitation |
Watson B, Mosomane S, Kuijpers J, Roberts DP. Investigations into the residual strength of a 2.5 m wide Bushveld Merensky Reef crush pillar. 2008; http://hdl.handle.net/10204/3510. |
en_ZA |
dc.identifier.ris |
TY - Article
AU - Watson, BP
AU - Mosomane, SM
AU - Kuijpers, JS
AU - Roberts, David P
AB - The first crush pillars on the Bushveld platinum mines were introduced at Union Section in 1978. Before the introduction of crush pillars, serious problems were experienced when stoping advanced to a point 30 m to 40 m on both sides of the centre gully. At least three to four stopes were collapsing per month. Increased incidence of bursting has been reported on some mines at deeper levels but most of these bursts occur in the back areas. Nevertheless, the incidence of bursting increases the risk of falls of ground in already dangerous areas, and the larger pillars decrease the extraction ratio. This paper describes the evaluation of stress measurements conducted in two boreholes over a crush pillar with dimensions 2.5 m x 4.0 m, and a height of 1.2 m.The residual strength of the crush pillar with a width of 2.5 m was determined from a series of strain measurements in two boreholes and a Boussinesq matrix inversion. The calculated peak and residual stresses of the pillar were surprisingly high at 280 MPa and 48 MPa respectively. These high stress conditions are suspected to be associated with the narrow pillar geometry on the up-dip side and the stiff loading conditions under which failure took place. In order to get a more realistic evaluation of residual strength, a series of such measurements is recommended to establish a range of residual strengths for narrow crush pillars.
DA - 2008-08
DB - ResearchSpace
DP - CSIR
KW - Micro-cracks
KW - Crush pillars
KW - Non-linear stress-strain
KW - Uniaxial compressive strength
KW - Pillar axis
KW - In situ measurement
KW - Borehole
KW - Bushveld Merensky Reef
KW - Stopes
KW - Stopes collapses
KW - Bursting
KW - Metallurgy
KW - Mining
LK - https://researchspace.csir.co.za
PY - 2008
SM - 0038-223X
T1 - Investigations into the residual strength of a 2.5 m wide Bushveld Merensky Reef crush pillar
TI - Investigations into the residual strength of a 2.5 m wide Bushveld Merensky Reef crush pillar
UR - http://hdl.handle.net/10204/3510
ER -
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en_ZA |