Modified Design of Pillar Based on Estimated Stresses and Strength of Pillar in an Underground Limestone Mine

Details

• Personal Author:
  Bishop R ; Monsalve JJ ; Ripepi N ; Soni A
• Description:
  The design and strength of pillars are important parameters while implementing the room-and-pillar mining method in a limestone mine. The process becomes complex with the presence of the karst voids which are frequent phenomena in a carbonate rock formation. The karst system is a network of cavities that along with an omnipresent fracture network may lead to ground control issues in a limestone mine. The objective of this study is to provide a safe and reliable alternative design for a pillar in a case study mine for safe and efficient ore recovery. This research is a continuation of a previous study aimed at studying the effect of karst void on the strength of the same limestone pillar. It was assessed from the calculated pillar strength and the estimated redistributed stresses that the pillar is capable of countering more stress than is currently imparted on it. Numerical modeling studies combining in situ stress determination and excavation sequencing were used to estimate the existing stresses on the pillar. Different possibilities of modification to existing pillar design were simulated using Distinct-Element Modeling (DEM) to determine a better design. Discrete fracture networks (DFNs) were included to imitate the effect of the presence of discontinuities. An effort is also made to understand the variation of pillar strength with height for karst-affected pillars using two different constitutive models. This study serves as a preliminary investigation in terms of improving the future design of pillars and also while recovering old pillars prone to karst formation. [Description provided by NIOSH]
• Subjects:
  Mining Occupational Health Safety
• Keywords:
  3DEC Author Keywords: Pillar Strength Carbonates DEM DFN Excavations Ground Control Karst Limestone Mines Models Pillar Design Pillar Mechanics Rock Mechanics Room And Pillar Mining Secondary Recovery Stress Underground Mines

  More +
• ISSN:
  2524-3462
• Document Type:
  Text
• Funding:
  Contract
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  40
• Issue:
  2
• NIOSHTIC Number:
  nn:20067273
• Citation:
  Min Metall Explor 2023 Apr; 40(2):529-541
• Contact Point Address:
  Aman Soni, Mining and Minerals Engineering, Virginia Polytechnic Institute & State University, Blacksburg, VA, USA
• Email:
  amansoni@vt.edu
• CAS Registry Number:
  Limestone (CAS RN 1317-65-3)
• Federal Fiscal Year:
  2023
• Performing Organization:
  Virginia Polytechnic Institute
• Peer Reviewed:
  True
• Start Date:
  20160901
• Source Full Name:
  Mining, Metallurgy & Exploration
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:ebff3bf3ebdd12ffac39d2e9b5e15343279acc25b07abd4676b5d70057cfa949c97c752387308cc1ae456bc9b5359e15064058dd6702619334d4ec1294990a1d
• Download URL:
  https://stacks.cdc.gov/view/cdc/231383/cdc_231383_DS1.pdf
• File Type:
  [PDF - 3.25 MB ]