Insight into Hard Rock Pillar Behavior from Numerical Simulation Using a Progressive S-Shaped Failure Criterion

Details

• Personal Author:
  Sinha S ; Walton G ; Sinha S ; Walton G
• Description:
  In recent decades, several researchers have found that the behavior of brittle rocks near excavation boundaries under intermediate to high stress conditions is best described by a Cohesion-Weakening-Friction-Strengthening (CWFS) Model. The advantage of CWFS over conventional shear strength failure criterions in describing the process of extensile fracturing (spalling) makes it ideal for modelling damage processes in hard rock pillars. The majority of numerical studies of pillars to date, however, have focused on the application of strain-softening material models; while these models may be suitable for capturing mine-scale behavior of pillar systems, they provide little insight into the mechanisms governing pillar stability. Recently, the concept of an S-shaped strength criterion was introduced which combined the CWFS strength model (at low confining stress) with the classical shear strength envelopes (at higher confining stress). Theoretically, such a model should better capture the brittle fracturing phenomenon along the ribs and the shear fracturing inside the pillar where confinement is high. In this study, the progressive S-shaped strength envelope has been implemented in FLAC3D using a bilinear strength model and has been demonstrated to exhibit some well-documented behavior seen in failing pillars. As a final step, a range of width/height ratios were tested and the results were compared against published field data, empirical strength envelopes, and previous modelling attempts presented in the literature. [Description provided by NIOSH]
• Subjects:
  Geology Occupational Health Safety
• Keywords:
  Fracturing Geotechnical Engineering Pillar Mechanics Rock Mechanics
• Publisher:
  American Rock Mechanics Association (ARMA)
• Document Type:
  Text
• Funding:
  Contract
• Genre:
  Proceedings ; Proceedings
• Place as Subject:
  Colorado ; OSHA Region 8
• CIO:
  National Institute for Occupational Safety and Health (NIOSH) ; National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health ; Workplace Safety & Health
• Location:
  North America ; North America
• NIOSHTIC Number:
  nn:20068897
• Citation:
  51st US Rock Mechanics/Geomechanics Symposium, June 25-28, 2017, San Francisco, California. Alexandria, VA: American Rock Mechanics Association (ARMA), 2017 Jun; :ARMA 17-174
• Federal Fiscal Year:
  2017
• Performing Organization:
  Colorado School of Mines, Golden
• Peer Reviewed:
  False
• Start Date:
  20160915
• Source Full Name:
  51st US Rock Mechanics/Geomechanics Symposium, June 25-28, 2017, San Francisco, California
• End Date:
  20210914
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:9031ed5c27217896e237b8872089644c52713004b74d224787ff7b7bf8d2d548461378edade659b96db06b9c5b79bcac94ee45bd21949f998c920b50d73b99b0
• Download URL:
  https://stacks.cdc.gov/view/cdc/207461/cdc_207461_DS1.pdf
• File Type:
  [PDF - 2.21 MB ]