Photogrammetric Prediction of Rock Fracture Properties and Validation with Metric Shear Tests
An accurate understanding of jointed rock mass behavior is important in many applications ranging from deep geological disposal of nuclear waste, to deep mining, and to urban geoengineering projects. The roughness of rock fractures and the matching of the fracture surfaces are the key contributors t...
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MDPI AG
2021-07-01
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| Series: | Geosciences |
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| Online Access: | https://www.mdpi.com/2076-3263/11/7/293 |
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| author | Lauri Uotinen Masoud Torkan Alireza Baghbanan Enrique Caballero Hernández Mikael Rinne |
| author_facet | Lauri Uotinen Masoud Torkan Alireza Baghbanan Enrique Caballero Hernández Mikael Rinne |
| author_sort | Lauri Uotinen |
| collection | DOAJ |
| description | An accurate understanding of jointed rock mass behavior is important in many applications ranging from deep geological disposal of nuclear waste, to deep mining, and to urban geoengineering projects. The roughness of rock fractures and the matching of the fracture surfaces are the key contributors to the shear strength of rock fractures. In this research, push shear tests with three normal stress levels of 3.6, 6.0, and 8.5 kPa were conducted on two granite samples with artificially induced well-matching tensile fractures with sizes of 500 mm × 250 mm and 1000 mm × 500 mm. The large sample reached on average a −60% weaker peak shear stress than the medium-sized sample, and a strong negative scale effect was observed in the peak shear strength. The roughness of the surfaces was measured using a profilometer and photogrammetry. The scale-corrected profilometer-based method (joint roughness coefficient, JRC) underestimates the peak friction angle for the medium-sized slabs by −27% for the medium sample and −9% for the large sample. The photogrammetry-based (<i>Z</i>′<sub>2</sub>) method produces an estimate with −7% (medium) and + 12% (large) errors. The photogrammetry-based <i>Z</i>′<sub>2</sub> is an objective method that consistently produces usable estimates for the JRC and peak friction angle. |
| first_indexed | 2024-03-10T09:38:00Z |
| format | Article |
| id | doaj.art-287f1b1c5da346c39b2f4c8a14d3a076 |
| institution | Directory Open Access Journal |
| issn | 2076-3263 |
| language | English |
| last_indexed | 2024-03-10T09:38:00Z |
| publishDate | 2021-07-01 |
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| series | Geosciences |
| spelling | doaj.art-287f1b1c5da346c39b2f4c8a14d3a0762023-11-22T03:51:55ZengMDPI AGGeosciences2076-32632021-07-0111729310.3390/geosciences11070293Photogrammetric Prediction of Rock Fracture Properties and Validation with Metric Shear TestsLauri Uotinen0Masoud Torkan1Alireza Baghbanan2Enrique Caballero Hernández3Mikael Rinne4Department of Civil Engineering, School of Engineering, Aalto University, FI-02150 Espoo, FinlandDepartment of Civil Engineering, School of Engineering, Aalto University, FI-02150 Espoo, FinlandDepartment of Mining Engineering (DME), Isfahan University of Technology (IUT), Isfahan 84156-83111, IranStress Measurement Company Oy, FI-00180 Helsinki, FinlandDepartment of Civil Engineering, School of Engineering, Aalto University, FI-02150 Espoo, FinlandAn accurate understanding of jointed rock mass behavior is important in many applications ranging from deep geological disposal of nuclear waste, to deep mining, and to urban geoengineering projects. The roughness of rock fractures and the matching of the fracture surfaces are the key contributors to the shear strength of rock fractures. In this research, push shear tests with three normal stress levels of 3.6, 6.0, and 8.5 kPa were conducted on two granite samples with artificially induced well-matching tensile fractures with sizes of 500 mm × 250 mm and 1000 mm × 500 mm. The large sample reached on average a −60% weaker peak shear stress than the medium-sized sample, and a strong negative scale effect was observed in the peak shear strength. The roughness of the surfaces was measured using a profilometer and photogrammetry. The scale-corrected profilometer-based method (joint roughness coefficient, JRC) underestimates the peak friction angle for the medium-sized slabs by −27% for the medium sample and −9% for the large sample. The photogrammetry-based (<i>Z</i>′<sub>2</sub>) method produces an estimate with −7% (medium) and + 12% (large) errors. The photogrammetry-based <i>Z</i>′<sub>2</sub> is an objective method that consistently produces usable estimates for the JRC and peak friction angle.https://www.mdpi.com/2076-3263/11/7/293shear testscale effectroughnessphotogrammetryfriction angle |
| spellingShingle | Lauri Uotinen Masoud Torkan Alireza Baghbanan Enrique Caballero Hernández Mikael Rinne Photogrammetric Prediction of Rock Fracture Properties and Validation with Metric Shear Tests Geosciences shear test scale effect roughness photogrammetry friction angle |
| title | Photogrammetric Prediction of Rock Fracture Properties and Validation with Metric Shear Tests |
| title_full | Photogrammetric Prediction of Rock Fracture Properties and Validation with Metric Shear Tests |
| title_fullStr | Photogrammetric Prediction of Rock Fracture Properties and Validation with Metric Shear Tests |
| title_full_unstemmed | Photogrammetric Prediction of Rock Fracture Properties and Validation with Metric Shear Tests |
| title_short | Photogrammetric Prediction of Rock Fracture Properties and Validation with Metric Shear Tests |
| title_sort | photogrammetric prediction of rock fracture properties and validation with metric shear tests |
| topic | shear test scale effect roughness photogrammetry friction angle |
| url | https://www.mdpi.com/2076-3263/11/7/293 |
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