Endre søk
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Effekten av inspänningen på fragmentering samt dynamiska mätningar försättningens rörelser: Resultat från småskaliga sprängförsök
2011 (engelsk)Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
Abstract [en]

Every mining method, underground or surface is adopted based on economical and geological criteria. The tests in this thesis have been conducted based on Sub - level caving mining method which is used by LKAB mines. The aim of these tests was to investigate the fragmentation in different long delay times and conditions, in small scale tests. The second task is to investigate the burden behavior under confined conditions. There were two different designs. The first design included a magnetic mortar with 5 holes and specific charge 2.56 kg/m3. The second design included a magnetic mortar with the same properties as in the first design but with a different specific charge 4.16 kg/m3. The dimensions of the blocks were 110x270x210 mm and the diameter of the holes was Ø 11. The common point in both designs was the ratio of spacing to burden which was kept stable at 1.57 (110/70 ≈ 82.5/52.33). The correlation between the two different designs has been done based on the delay time. The delay time is adjusted in that way so that the results from the two designs would be compatible. The results show an improvement in fragmentation for long delay by 32.94 % from 110 μsec to 218 μsec. Additionally, they show the difference between V – shape and sequential firing pattern which is 46 % under confined conditions. The second task of the thesis was to investigate the burden movement and velocity. Three different methods have been implemented; draw wire, accelerometers and nails. The draw wire was slow to give good results probably due to high accelerations and some inertia issues. The accelerometers did not show the burden movement because the signal of the burden movement was hidden behind the reflections of the waves. The nails gave results that are good for analysis. Finally, the burden velocity had a peak value of 22 m/s and a maximum compaction of 14.3 mm. The value of compaction varies depending on different cases. The given compaction corresponded to V – shape firing pattern. However, for the sequential firing pattern the compaction was 12.6 mm, something that is reasonable due to different movement of the burden.

sted, utgiver, år, opplag, sider
2011. , s. 173
Emneord [en]
Technology, fragmentation, small scale tests, burden velocity, burden movement, compaction, confined/unconfined blasting
Emneord [sv]
Teknik
Identifikatorer
URN: urn:nbn:se:ltu:diva-58261Lokal ID: ed75e2e5-6fcb-4c21-955b-5434f1636f58OAI: oai:DiVA.org:ltu-58261DiVA, id: diva2:1031649
Fag / kurs
Student thesis, at least 30 credits
Utdanningsprogram
Civil Engineering, master's level
Merknad
Validerat; 20110629 (anonymous)Tilgjengelig fra: 2016-10-04 Laget: 2016-10-04bibliografisk kontrollert

Open Access i DiVA

fulltekst(14963 kB)126 nedlastinger
Filinformasjon
Fil FULLTEXT02.pdfFilstørrelse 14963 kBChecksum SHA-512
8f1d41fcab47f66fa6733302521f782622f8642f6fd472e335f553aeaf4a78ccbb3d17c09fa55a934536ca5c189c324299ae57457733ff098552543f28d6ec6f
Type fulltextMimetype application/pdf

Søk i DiVA

Av forfatter/redaktør
Petropoulos, Nikolaos

Søk utenfor DiVA

GoogleGoogle Scholar
Totalt: 126 nedlastinger
Antall nedlastinger er summen av alle nedlastinger av alle fulltekster. Det kan for eksempel være tidligere versjoner som er ikke lenger tilgjengelige

urn-nbn

Altmetric

urn-nbn
Totalt: 51 treff
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf