JOURNAL OF ROCK MECHANICS

JOURNAL OF ROCK MECHANICS

Development of a new model to predict the shear strength of unfilled natural joints

Document Type : Original Article

Authors
Masoud Shamsaldin Saeed 1
Saeed Karimi Nasab 1
Hossein Jalalifar 2
1 Department of Mining Engineering, Shahid Bahonar University of Kerman,, Iran.
2 Department of Petroleum Engineering, Shahid Bahonar University of Kerman, Kerman, Iran.
10.22034/IRSRM.2024.400038.1002
Abstract
The strength of rock mass is significantly controlled by the presence of discontinuities and instabilities at shallow depth may occur by sliding along rock joints. This phenomenon is more important at shallow depths. The aim of this study is to investigate the shear behavior of natural, unfilled rock joints that were obtained from core drilling. For this purpose, direct shear tests were conducted on 37 natural rock joints in constant normal loading condition. All the specimens were obtained from core drilling of a geotechnical project. The morphological characteristics of joints were captured by photogrammetry before the test. Based on Barton and other classical theories, laboratory test data, and using the quantitative three-dimensional morphological parameters, a new peak shear strength criterion has been proposed for natural, unfilled rock joints. The predicted peak strengths using the new model match well with the observed values. In addition, a comparison of the new criterion with previous 3D models shows that compared to other criteria, the predicted value based on the new criterion is more consistent with the test data. It was observed that the estimation accuracy of the new criterion is appropriate for natural, unfilled joints.
Keywords
joints
Shear
Morphology
Photogrammetry
Subjects
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JOURNAL OF ROCK MECHANICS
Volume 8, Issue 3
Autumn 2024
Pages 103-110