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Analyzing the Effect of Bolt Spacing on Coal Rib Stability Through Numerical Simulation

Public Domain


Details

  • Personal Author:
  • Description:
    Rib falls pose a major safety risk in underground coal mines, and there is currently no standardized approach for rib support design in the U.S. coal mines. To tackle this issue, a standalone application, Design of Rib Support (DORS), was developed for rib stability assessment and rib support design under development load. The last step of the rib support design in DORS was to calculate the bolt spacing from the recommended rib support density, bolt grade and number of bolts. Notably, the change of bolt grade and the number of bolts significantly affects bolt spacing, but it remains unclear how varying bolt spacing impacts the supported rib factor of safety (RibFOS). In this study, numerical simulations were conducted to analyze the influence of bolt spacing on coal rib stability. Initially, plane-strain 3DEC models were used to estimate the RibFOS of unsupported solid coal ribs, serving as a baseline for rib stability evaluation. Subsequently, 3D models were conducted for supported solid coal pillar ribs. A parametric study was conducted to investigate the influence of bolt spacing on the supported RibFOS under different conditions, such as varying overburden depths and bolt lengths. The simulation results show a general trend of reduced supported RibFOS with the increase in bolt spacing, and the trend can be further affected by varying conditions. The variation of supported RibFOS with bolt spacing can be quantified by normalizing the supported RibFOS to its values with a bolt spacing of 0.3 m. Finally, when the rib support density was maintained by varying bolt grade and bolt spacing, the influence of bolt spacing can still be observed in the results. Thus, it is essential to consider this bolt spacing effect in rib support design. [Description provided by NIOSH]
  • Subjects:
  • Keywords:
  • Series:
    Mining Publications
  • ISBN:
    9780979497599
  • Publisher:
    American Rock Mechanics Association (ARMA)
  • Document Type:
    Text
  • Genre:
    Proceedings
  • Place as Subject:
  • CIO:
    National Institute for Occupational Safety and Health (NIOSH)
  • Division:
    PMRD - Pittsburgh Mining Research Division
  • Topic:
    Workplace Safety & Health
  • Location:
    North America
  • NIOSHTIC Number:
    nn:20070427
  • Citation:
    58th US Rock Mechanics/Geomechanics Symposium, June 23-26, 2024, Golden, Colorado. Alexandria, VA: American Rock Mechanics Association (ARMA), 2024 Jun; :ARMA-24-0582
  • Federal Fiscal Year:
    2024
  • Peer Reviewed:
    False
  • Source Full Name:
    58th US Rock Mechanics/Geomechanics Symposium, June 23-26, 2024, Golden, Colorado
  • Collection(s):
  • Main Document Checksum:
    urn:sha-512:40a87149ba2a1f38cb1e6d247dab3ba361e467851018268acbd6529180ab8a7730defbef91f1e940dadc67d1004490abb0de9e5037785872afab6b3857f510cf
  • Download URL:
  • File Type:
    Filetype[PDF - 545.34 KB ]
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