A New Characterization Method for Rock Joint Roughness Considering the Mechanical Contribution of Each Asperity Order
Open Access
- 22 July 2021
- journal article
- research article
- Published by MDPI AG in Applied Sciences
- Vol. 11 (15), 6734
- https://doi.org/10.3390/app11156734
Abstract
The morphology of the joint surface is multi-scale, and it can be divided into first-order asperity (waviness) and second-order asperity (unevenness). At present, the joint roughness characterization formula considers only the morphology contribution of waviness and unevenness components and does not fully consider their mechanical contribution. At same time, the relationship between the mechanical contribution and the morphology contribution is still unclear. Thus, the characterization formula considering the mechanical contribution of waviness and unevenness needs to be further studied. In this study, the standard joint roughness coefficient (JRC) profiles were first decomposed into waviness and unevenness. Then, three types of joint specimens with different asperity orders (flat, the standard JRC profile, and the profile containing only waviness) were prepared by the 3D engraving technique. Finally, direct shear tests were carried out on 39 sets of red sandstone joint specimens under three normal stresses. The mechanical contributions of waviness and unevenness were studied, the relationship between the mechanical contribution and the morphology contribution of waviness and unevenness was analyzed, and the characterization formula considering the mechanical contribution of waviness and unevenness was established. The results showed that the following: (1) the method combining the ensemble empirical mode decomposition (EEMD) and the critical decomposition level could be used to separate the waviness and unevenness from the joint surface; (2) the mechanical contribution of the waviness and unevenness decreased with the increase in normal stress; (3) the relationship between the mechanical contribution ratio and the statistical parameter ratio of the waviness and unevenness can be describe by power function; and (4) the roughness characterization formula considering the mechanical contribution and morphology contribution was established. This study will enhance the accurate evaluation of the roughness coefficient and shear strength of the joint specimen.Funding Information
- Hubei Provincial Department of Education (Q20201109)
- Natural Science Foundation of Hubei Province (2020CFB123)
- Science and Technology Department of Hubei Province (2020BCA082)
This publication has 65 references indexed in Scilit:
- Normality Tests for Statistical Analysis: A Guide for Non-StatisticiansInternational Journal of Endocrinology and Metabolism, 2012
- Underestimation of roughness in rough rock jointsInternational Journal for Numerical and Analytical Methods in Geomechanics, 2008
- Reassessing the Joint Roughness Coefficient (JRC) Estimation Using Z 2Rock Mechanics and Rock Engineering, 2001
- Quantitative Parameters for Rock Joint Surface RoughnessRock Mechanics and Rock Engineering, 2000
- The empirical mode decomposition and the Hilbert spectrum for nonlinear and non-stationary time series analysisProceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 1998
- Interlock/friction model for dynamic shear response in natural jointed rockInternational Journal of Rock Mechanics and Mining Sciences, 1996
- Study of rock joints under cyclic loading conditionsRock Mechanics and Rock Engineering, 1993
- Constitutive models for rock discontinuities with dilatancy and surface degradationInternational Journal for Numerical and Analytical Methods in Geomechanics, 1987
- International society for rock mechanics commission on standardization of laboratory and field tests: Suggested methods for the quantitative description of discontinuities in rock massesInternational Journal of Rock Mechanics and Mining Sciences, 1978
- The shear strength of rock joints in theory and practiceRock Mechanics and Rock Engineering, 1977