Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Crosscut deformation as a function of ring blast location in LKAB's Malmberget mine: Tvärortsdeformation som funktion av produktionsskjutning i LKABs Malmbergsgruva
Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.ORCID iD: 0000-0002-3661-1802
2016 (English)Conference paper, Oral presentation only (Other academic)
Abstract [en]

Between 2007 and 2010, 20 SMART cable bolts collected crosscut deformation data on levels 932 and 962 of the Malmberget mine. Using 3D mapping techniques, the coordinates of each instrument were determined, along with the coordinates of every production blast occurring during their lifetimes. These coordinates were used to calculate the relative distance and inclination angle (vertical angle above the horizontal plane) from each instrument to each production blast. The instrument data was analyzed to determine average-weekly deformation magnitude and rate.Specific deformation trends were identified when the deformation data was compared to the average weekly distance and inclination angle of the blasts. When blasts detonated at the same distance were compared, those blasts occurring on the level above the instrumentation produced greater deformation rates on every recorded occasion. Also, decreased distances produced higher deformation rates. These rates were all highly influenced by the varying RQD present at each bolt location, with higher RQD giving less deformation. While these results are not unexpected, they resulting data produced further interesting connections when the actual position of each blast was considered.In total, 1026 data points were produced from the eight bolts that recorded significant movement. Of these data points, only 49 instances (5%) occurred where deformation rates higher than 150 μm/day were realized. Given that increased deformation rate is a known indicator of instability or approaching failure, the individual blasts that created these 49 instances were investigated to see if causal patterns could be determined.Of the 49 elevated-rate readings, specific production blasts could be identified for 45 of them. Six types of blasting events were identified as common triggers. Nearly two-thirds of these events were caused by types of stress redistribution including redistribution ontoartificial pillars created during mining, and redistribution caused by the opening blasts in a new crosscut.Using the causal events and deformation patterns as keys, it may be possible to develop a new method of empirical support design, wherein expected deformation could be anticipated and the necessary support installed in advance. This could prevent entry degradation, improve safety, and potentially lower support costs by tailoring support to suit the particular needs of a location, rather than using a blanket support policy.

Place, publisher, year, edition, pages
2016.
Keywords [en]
deformation, sub-level caving, Civil engineering and architecture - Geoengineering and mining engineering
Keywords [sv]
Samhällsbyggnadsteknik och arkitektur - Geoteknik och gruvteknik
National Category
Other Civil Engineering
Research subject
Mining and Rock Engineering
Identifiers
URN: urn:nbn:se:ltu:diva-29452Local ID: 2f00e877-144e-42cc-bfa8-8b5ff4f461c1OAI: oai:DiVA.org:ltu-29452DiVA, id: diva2:1002676
Conference
Bergmekanikdag 2016 : 50-års jubileum 14/03/2016 - 14/03/2016
Note
Godkänd; 2016; 20160421 (trijon)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-06-12Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

http://www.befoonline.org/UserFiles/Archive/618/Bergmekanikdagen_2016.zip

Authority records BETA

Jones, Tristan

Search in DiVA

By author/editor
Jones, Tristan
By organisation
Mining and Geotechnical Engineering
Other Civil Engineering

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 200 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf