Numerical Modeling of Yielding Chain Pillars in Longwall Mines

Details

• Personal Author:
  Badr S ; Ozbay U ; Salamon M ; Schissler A
• Description:
  The practice in thick seam longwall mining at depths of 500 m and more shows that considerable sloughing of chain pillars, sometimes accompanied by bumps, may occur during development stage. The ability of these pillars to continue functioning as roof support during development and long walling stages has to be assured for a safe and economical mining operation. Although already being used, little is known quantitatively about the response of these "yielding" chain pillars to varying loading conditions that come about during different stages of longwall mining. The paper presents the results from case history reviews and numerical modeling studies performed with the objective of improving the understanding of yield pillar behavior. The case history review indicates that yield pillars with width:height ratios 3 to 6 performed satisfactorily. The numerical modeling studies using a three-dimensional finite difference code FLAC3D [1] allowed realistic simulations of complex mining geofiletries and loading conditions of longwall mining. The numerical model incorporates a strain-softening constitutive model for post-peak pillar behavior and a non-linearly elastic material behavior for sin1ulating gob compaction. The differences in performance of pillars with strain softening material and traditional Mohr-Coulomb material are also highlighted. [Description provided by NIOSH]
• Subjects:
  Mining Occupational Health Safety
• Keywords:
  Longwall-mining Mine-shafts Mining-industry Models Room-and-pillar-mining Underground-mining
• ISBN:
  0772767084
• Publisher:
  University of Toronto Press
• Document Type:
  Text
• Funding:
  Cooperative Agreement
• Genre:
  Proceedings
• Place as Subject:
  Colorado ; OSHA Region 8
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  99-106
• Volume:
  1
• NIOSHTIC Number:
  nn:20030551
• Citation:
  NARMS-TAC 2002, "Mining and tunnelling innovation and opportunity," proceedings of the 5th American Rock Mechanics Symposium and the 17th Tunnelling Association of Canada Conference, July 7-10, 2002, Toronto, Ontario, Canada. Hammah R, Bawden W, Curran J, Telesnicki M, eds. Toronto, Ontario, Canada: University of Toronto Press, 2002 Jul; 1:99-106
• Editor(s):
  Hammah R; Bawden W; Curran J; Telesnicki M
• Federal Fiscal Year:
  2002
• Performing Organization:
  Colorado School of Mines
• Peer Reviewed:
  False
• Start Date:
  19990901
• Source Full Name:
  NARMS-TAC 2002, "Mining and tunnelling innovation and opportunity," proceedings of the 5th American Rock Mechanics Symposium and the 17th Tunnelling Association of Canada Conference, July 7-10, 2002, Toronto, Ontario, Canada
• End Date:
  20050831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:e138397f62df538029fc290b3df7caab28c3800f3a7fb46c18c8ad31ebb99d69eeb7bdb57f7a768772c00045d14366bc5d94dad289cd222ce19b0bcf1a05ac0e
• Download URL:
  https://stacks.cdc.gov/view/cdc/191117/cdc_191117_DS1.pdf
• File Type:
  [PDF - 818.80 KB ]