Size-Dependent Mohr-Coulomb Failure Criterion

Details

• Personal Author:
  Mishra B ; Shi Q ; Zhao G ; Zhao Y ; Mishra B ; Shi Q ; Zhao G ; Zhao Y
• Description:
  Numerous experimental results show the compressive strength of rock decreases with the increase of rock size. Researchers have developed different empirical failure criteria to correlate the decreasing size effect of compressive strength. For the first time, this research theoretically derived the size-dependent Mohr-Coulomb failure criterion based on the Griffith theory. The failure criterion contains three parameters: the cohesion, the friction angle, and the scaling exponent, which can be determined based on the uniaxial compression test of different-sized specimens and the triaxial compression test of standard-sized specimens. The determined failure criterion can be used to predict the compressive strength of different-sized rocks at different compressive stress conditions. This failure criterion demonstrates that the cracks inside rock cause the size effect, and the crack length distribution affects the size effect. Next, this research developed the bonded-particle model of rock to verify the failure criterion. The rock model consists of matrix and cracks that are modeled by bonded particles and discrete fractures, respectively. The modeling result shows that the strength of matrix model is size independent, and the introduction of cracks causes the size effect of rock model. The parametric analysis verified the influence of crack length distribution on the size effect according to the failure criterion. At last, this research summarized the experimental data of uniaxial and triaxial compressive strength in previous size effect research to check the applicability of the failure criterion. The fitting result shows the failure criterion fits well with the experimental data. Moreover, this research found experimental evidence to support the failure criterion. [Description provided by NIOSH]
• Subjects:
  Geology Occupational Health Safety
• Keywords:
  Author Keywords: Size Effect Bonded-particle Model Compressive Strength Geologic Formations Geotechnical Engineering Griffith Theory Models Mohr-Coulomb Failure Criterion Rock Mechanics
• ISSN:
  1435-9529
• Document Type:
  Text
• Funding:
  Contract
• Genre:
  Journal Article ; Journal Article
• Place as Subject:
  OSHA Region 3 ; OSHA Region 8 ; Utah ; West Virginia
• 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
• Volume:
  82
• Issue:
  6
• NIOSHTIC Number:
  nn:20067698
• Citation:
  Bull Eng Geol Environ 2023 Jun; 82(6):218
• Contact Point Address:
  Yun Zhao, Department of Mining Engineering, West Virginia University, 1374 Evansdale Drive, Morgantown, WV, 26506, USA
• Email:
  cloudzhao0034@gmail.com
• Federal Fiscal Year:
  2023
• Performing Organization:
  West Virginia University
• Peer Reviewed:
  True
• Start Date:
  20160914
• Source Full Name:
  Bulletin of Engineering Geology and the Environment
• End Date:
  20200831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:64c97abae08de526c5b184a5f81d23cf2bc36dc32d5ed3318648d68a64caee7f12a90814349abec366ff3b176441adb387318c23da3b0198232c42be19c43711
• Download URL:
  https://stacks.cdc.gov/view/cdc/229961/cdc_229961_DS1.pdf
• File Type:
  [PDF - 7.42 MB ]