Estimating strength of pillars with karst voids in a room-and-pillar limestone mine.

Details

• Personal Author:
  Baggett JG ; Bishop R ; Monsalve JJ ; Ripepi N ; Soni A
• Description:
  Underground limestone deposits are prone to karst void formations due to the dissolution of carbonate rocks. These deposits offer permeable conditions to groundwater flow leading to the formation of a network of void spaces or cavities. The cavities can accommodate unconsolidated sediments and groundwater. Interaction of these voids with a prevalent discontinuity network may lead to ground control problems during mining operations. This paper presents a numerical estimation of the effect of karst voids on the strength of pillars in an underground room-and-pillar limestone mine. It is shown that these voids may contribute to a considerable decrease in pillar strength. Mining advances into such formations may lead to a sudden in-rush of groundwater or unconsolidated sediments. Apart from posing a safety hazard, this may also disrupt the pre-planned mine operations and design of the headings and pillars. The procedure for estimation of pillar strength using numerical modeling may provide a viable approach to design the future pillars detected with karst voids. Previous studies performed at the case study mine used ground-penetrating radar (GPR) to map the karst boundaries inside the pillar. Apart from the LiDAR scans used to map the discontinuity network around the pillars, some approximations were made to account for the inadequate discontinuity characterization data. Distinct-element modeling (DEM) is used to simulate the presence of voids and discontinuities in the form of discrete fracture networks (DFN). An effort is made to understand the importance of pillar design and dimensions in an underground limestone mine with karst voids to prevent local instability related to pillar failures. [Description provided by NIOSH]
• Subjects:
  Mining Occupational Health Safety
• Keywords:
  Author Keywords: Pillar Strength; Pillar Design; Karst; 3DEC; DEM; DFN; GPR; Ground Control Mining; Underground Mines; Limestone Mines; Ground Control; Rock Mechanics; Room And Pillar Mining; Pillar Mechanics; Structural Analysis; Tensile Strength;
• ISSN:
  2524-3462
• Document Type:
  Text
• Funding:
  Contract
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; OSHA Region 8 ; Utah ; Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  39
• Issue:
  3
• NIOSHTIC Number:
  nn:20065249
• Citation:
  Min Metall Explor 2022 Jun; 39(3):1073-1086
• Contact Point Address:
  Aman Soni, Mining and Minerals Engineering, Virginia Polytechnic Institute & State University, Blacksburg, VA, USA
• Email:
  amansoni@vt.edu
• Federal Fiscal Year:
  2022
• 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-512:837e10ed6a85f7f4268ddd39d5c058431061af7130d750bd76fb1cbdacdb2e897920fb13967756d5627f7129ae8df0e4f7cc75223bd2da7107acf694790bb365
• Download URL:
  https://stacks.cdc.gov/view/cdc/249382/cdc_249382_DS1.pdf
• File Type:
  [PDF - 3.80 MB ]