Underestimation of roughness in rough rock joints

Eun Soo Hong, Jong Sub Lee, In Mo Lee

Research output: Contribution to journalArticlepeer-review

78 Citations (Scopus)


Numerous studies have been made to improve Barton's shear strength model for the quantification of rock joints. However, in these previous studies, the roughness and shear strength of the rock joint have been underestimated especially for relatively high undulated profiles (joint roughness coefficient (JRC) > 14). The main factors of roughness underestimation in rough rock joints are investigated for the proper quantification of rock joint roughness. The aliasing effect and the roughness characteristics are analyzed by using artificial joint profiles and natural rock joint profiles. A 3D camera scanner is adopted to verify the main source of underestimation when using conventional measurement methods. Shear strength tests are carded out by using two types of shear apparatus to study the roughness mobilization characteristics, which may also affect the roughness underestimation. The results of joint roughness assessment, such as aliasing and undulation of waviness, show that the roughness can be underestimated in relatively rough joint profiles (JRC> 14). At least two components of roughness parameters are needed to properly represent the joint roughness, for example, the amplitude and the inclination angle of joint asperity. Roughness mobilization is affected by both the normal stress and the asperity scale.

Original languageEnglish
Pages (from-to)1385-1403
Number of pages19
JournalInternational Journal for Numerical and Analytical Methods in Geomechanics
Issue number11
Publication statusPublished - 2008 Aug 15


  • Aliasing
  • JRC
  • Roughness mobilization
  • Roughness parameter
  • Roughness underestimation

ASJC Scopus subject areas

  • Computational Mechanics
  • General Materials Science
  • Geotechnical Engineering and Engineering Geology
  • Mechanics of Materials


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