Strength and Elastic Properties of Paste Backfill at the Lucky Friday Mine, Mullan, Idaho

Details

• Personal Author:
  Arkoosh A ; Emery T ; Johnson JC ; Martin LA ; Seymour, Joseph B. ; Stepan M
• Description:
  At underground mines where cemented backfill is used for ground support, backfill strength properties are an important design consideration, particularly for underhand cut-and-fill mining operations where employees work directly beneath the placed fill. Following a backfill roof fall at a deep underground silver mine, standard tests were conducted to determine the strength and elastic properties of a typical paste backfill composed of cemented mill tailings. Unconfined compression tests and direct and indirect tensile tests were conducted with core samples obtained from paste fill slabs recovered from the roof fall. Test results indicated that the average tensile strengths determined by indirect methods (Brazilian and splitting tensile tests) were about twice the average tensile strength measured by direct tensile tests. To identify cold joints within the backfill, in situ direct tensile tests were also conducted on one of the larger backfill slabs using experimental test equipment. The results of these in situ tests were similar to the direct tensile tests and provided little evidence of additional cold joints within the slab. Elastic properties of the paste backfill were determined through compression tests with strain-gauged core samples. The results of this study are significant because they add to the sparse strength and elastic property data that are available for mine designs utilizing paste backfill. [Description provided by NIOSH]
• Subjects:
  Aerosols Air Pollutants, Occupational Mining Occupational Health Particulate Matter Safety
• Keywords:
  Cements Compression-tests Elastic-properties Environmental-control Ground-control Ground-stability In-situ-mining Materials-testing Mining-industry Rock-falls Sampling Structural-analysis Tensile-strength Testing-equipment Underground-mining

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• Series:
  Mining Publications
• ISBN:
  9781510810518
• Publisher:
  American Rock Mechanics Association (ARMA)
• Document Type:
  Text
• Genre:
  Proceedings
• Place as Subject:
  California ; Idaho ; OSHA Region 10 ; OSHA Region 9 ; Washington
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  PMRD - Pittsburgh Mining Research Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  3
• NIOSHTIC Number:
  nn:20048040
• Citation:
  49th US Rock Mechanics/Geomechanics Symposium, June 28 - July 1, 2015, San Francisco, California. Alexandria, VA: American Rock Mechanics Association (ARMA), 2015 Jun; 3:2321-2332
• Contact Point Address:
  Johnson, J.C., Seymour, National Institute for Occupational Safety and Health, Spokane, Washington, U.S.A.
• Federal Fiscal Year:
  2015
• NORA Priority Area:
  Mining
• Peer Reviewed:
  False
• Source Full Name:
  49th US Rock Mechanics/Geomechanics Symposium, June 28 - July 1, 2015, San Francisco, California
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:03a7c1868d9a891bf1e127794201db40f222fa9e7de15817b8b599919f0598acfde065a3ed8ff2b8810426e7f2fc892db5fabb47bb18f2174673205924858521
• Download URL:
  https://stacks.cdc.gov/view/cdc/228252/cdc_228252_DS1.pdf
• File Type:
  [PDF - 944.82 KB ]