Influence analysis of complex crack geometric parameters on mechanical properties of soft rock
Abstract Soft rocks, such as coal, are affected by sedimentary effects, and the surrounding rock mass of underground coal mines is generally soft and rich in joints and cracks. A clear and deep understanding of the relationship between crack geometric parameters and rock mechanics properties in crac...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2023-11-01
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| Series: | International Journal of Coal Science & Technology |
| Subjects: | |
| Online Access: | https://doi.org/10.1007/s40789-023-00649-7 |
| _version_ | 1797454070200401920 |
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| author | Yang Zhao Xin He Lishuai Jiang Zongke Wang Jianguo Ning Atsushi Sainoki |
| author_facet | Yang Zhao Xin He Lishuai Jiang Zongke Wang Jianguo Ning Atsushi Sainoki |
| author_sort | Yang Zhao |
| collection | DOAJ |
| description | Abstract Soft rocks, such as coal, are affected by sedimentary effects, and the surrounding rock mass of underground coal mines is generally soft and rich in joints and cracks. A clear and deep understanding of the relationship between crack geometric parameters and rock mechanics properties in cracked rock is greatly important to the design of engineering rock mass structures. In this study, computed tomography (CT) scanning was used to extract the internal crack network of coal specimens. Based on the crack size and dominant crack number, the parameters of crack area, volume, length, width, and angle were statistically analyzed by different sampling thresholds. In addition, the Pearson correlation coefficients between the crack parameters and uniaxial compression rock mechanics properties (uniaxial compressive strength UCS, elasticity modulus E) were calculated to quantitatively analyze the impact of each parameter. Furthermore, a method based on Pearson coefficients was used to grade the correlation between crack geometric parameters and rock mechanical properties to determine threshold values. The results indicated that the UCS and E of the specimens changed with the varied internal crack structures of the specimens, the crack parameters of area, volume, length and width all showed negative correlations with UCS and E, and the dominant crack played an important role both in weakening strength and stiffness. The crack parameters of the angle are all positively correlated with the UCS and E. More crack statistics can significantly improve the correlation between the parameters of the crack angle and the rock mechanics properties, and the statistics of the geometric parameters of at least 16 cracks or the area larger than 5 mm2 are suggested for the analysis of complex cracked rock masses or physical reproduction using 3D printing. The results are validated and further analyzed with triaxial tests. The findings of this study have important reference value for future research regarding the accurate and efficient selection of a few cracks with a significant influence on the rock mechanical properties of surrounding rock mass structures in coal engineering. |
| first_indexed | 2024-03-09T15:32:56Z |
| format | Article |
| id | doaj.art-30d1cef2158e4f63ac835d88fd884397 |
| institution | Directory Open Access Journal |
| issn | 2095-8293 2198-7823 |
| language | English |
| last_indexed | 2024-03-09T15:32:56Z |
| publishDate | 2023-11-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | International Journal of Coal Science & Technology |
| spelling | doaj.art-30d1cef2158e4f63ac835d88fd8843972023-11-26T12:09:12ZengSpringerOpenInternational Journal of Coal Science & Technology2095-82932198-78232023-11-0110111510.1007/s40789-023-00649-7Influence analysis of complex crack geometric parameters on mechanical properties of soft rockYang Zhao0Xin He1Lishuai Jiang2Zongke Wang3Jianguo Ning4Atsushi Sainoki5State Key Laboratory of Mining Disaster Prevention and Control, Shandong University of Science and TechnologyState Key Laboratory of Mining Disaster Prevention and Control, Shandong University of Science and TechnologyState Key Laboratory of Mining Disaster Prevention and Control, Shandong University of Science and TechnologyState Key Laboratory of Mining Disaster Prevention and Control, Shandong University of Science and TechnologyCollege of Energy and Mining Engineering, Shandong University of Science and TechnologyFaculty of Advanced Science and Technology, Kumamoto UniversityAbstract Soft rocks, such as coal, are affected by sedimentary effects, and the surrounding rock mass of underground coal mines is generally soft and rich in joints and cracks. A clear and deep understanding of the relationship between crack geometric parameters and rock mechanics properties in cracked rock is greatly important to the design of engineering rock mass structures. In this study, computed tomography (CT) scanning was used to extract the internal crack network of coal specimens. Based on the crack size and dominant crack number, the parameters of crack area, volume, length, width, and angle were statistically analyzed by different sampling thresholds. In addition, the Pearson correlation coefficients between the crack parameters and uniaxial compression rock mechanics properties (uniaxial compressive strength UCS, elasticity modulus E) were calculated to quantitatively analyze the impact of each parameter. Furthermore, a method based on Pearson coefficients was used to grade the correlation between crack geometric parameters and rock mechanical properties to determine threshold values. The results indicated that the UCS and E of the specimens changed with the varied internal crack structures of the specimens, the crack parameters of area, volume, length and width all showed negative correlations with UCS and E, and the dominant crack played an important role both in weakening strength and stiffness. The crack parameters of the angle are all positively correlated with the UCS and E. More crack statistics can significantly improve the correlation between the parameters of the crack angle and the rock mechanics properties, and the statistics of the geometric parameters of at least 16 cracks or the area larger than 5 mm2 are suggested for the analysis of complex cracked rock masses or physical reproduction using 3D printing. The results are validated and further analyzed with triaxial tests. The findings of this study have important reference value for future research regarding the accurate and efficient selection of a few cracks with a significant influence on the rock mechanical properties of surrounding rock mass structures in coal engineering.https://doi.org/10.1007/s40789-023-00649-7CT scanningComplex crackSampling thresholdSoft rockRock mechanicsCrack geometric parameters |
| spellingShingle | Yang Zhao Xin He Lishuai Jiang Zongke Wang Jianguo Ning Atsushi Sainoki Influence analysis of complex crack geometric parameters on mechanical properties of soft rock International Journal of Coal Science & Technology CT scanning Complex crack Sampling threshold Soft rock Rock mechanics Crack geometric parameters |
| title | Influence analysis of complex crack geometric parameters on mechanical properties of soft rock |
| title_full | Influence analysis of complex crack geometric parameters on mechanical properties of soft rock |
| title_fullStr | Influence analysis of complex crack geometric parameters on mechanical properties of soft rock |
| title_full_unstemmed | Influence analysis of complex crack geometric parameters on mechanical properties of soft rock |
| title_short | Influence analysis of complex crack geometric parameters on mechanical properties of soft rock |
| title_sort | influence analysis of complex crack geometric parameters on mechanical properties of soft rock |
| topic | CT scanning Complex crack Sampling threshold Soft rock Rock mechanics Crack geometric parameters |
| url | https://doi.org/10.1007/s40789-023-00649-7 |
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