Numerical Test Study of the Microscale Failure Modes and Fractal Analysis of Lower Cambrian Shale Based on Digital Images
To reveal the effect of confining pressure on the mechanical properties and rupture modes of quartz-bearing shale, the shale core of the no. 3 block of Fenggang, Guizhou Province, China, was analyzed by nuclear magnetic resonance, polarized light microscope thin section observation and identificatio...
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| Format: | Article |
| Language: | English |
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Wiley
2020-01-01
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| Series: | Advances in Civil Engineering |
| Online Access: | http://dx.doi.org/10.1155/2020/8819711 |
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| author | Hengtao Cui Zhonghu Wu Liping Li Jing Wang Shuguang Song Shangqu Sun Yujun Zuo Hao Liu Yili Lou |
| author_facet | Hengtao Cui Zhonghu Wu Liping Li Jing Wang Shuguang Song Shangqu Sun Yujun Zuo Hao Liu Yili Lou |
| author_sort | Hengtao Cui |
| collection | DOAJ |
| description | To reveal the effect of confining pressure on the mechanical properties and rupture modes of quartz-bearing shale, the shale core of the no. 3 block of Fenggang, Guizhou Province, China, was analyzed by nuclear magnetic resonance, polarized light microscope thin section observation and identification, and core X-ray whole-rock minerals diffraction analysis to determine the distribution of shale minerals in the Niutitang Formation. On the microscale, based on digital image processing technology, this paper characterizes the nonuniformity of minerals in shale, a numerical model that can reflect the true microstructure of shale. Then, the failure process of shale under different confining pressures was simulated. The results show that when the shale is loaded with vertical displacement under different confining pressures, the compressive strength and elastic modulus of the sample change significantly. The failure mode can be roughly divided into three types: the inverted V-shaped (0 MPa, 2 MPa, and 4 MPa), V-shaped (6 MPa and 8 MPa), and inverted Z-shaped (10 MPa). Since the development of fractal theory provides a new space for studying the damage and fracture of rocks, the damage evolution and failure process of shale can also be regarded as the fractal process of cracks, in which the fractal dimension is the core parameter. The calculation is different under different stress levels. The fractal dimension under the condition of confining pressure shows that the value of the fractal dimension is greatly affected by the effect of confining pressure. When the fractal dimension is higher, the fracture mode is more complicated, and the internal damage degree is more serious. The research results provide important theoretical guidance for shale gas fracturing production. |
| format | Article |
| id | doaj-art-338bc69aec3746d4aebb36ddf7e037d6 |
| institution | Kabale University |
| issn | 1687-8086 1687-8094 |
| language | English |
| publishDate | 2020-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Advances in Civil Engineering |
| spelling | doaj-art-338bc69aec3746d4aebb36ddf7e037d62025-02-03T01:00:38ZengWileyAdvances in Civil Engineering1687-80861687-80942020-01-01202010.1155/2020/88197118819711Numerical Test Study of the Microscale Failure Modes and Fractal Analysis of Lower Cambrian Shale Based on Digital ImagesHengtao Cui0Zhonghu Wu1Liping Li2Jing Wang3Shuguang Song4Shangqu Sun5Yujun Zuo6Hao Liu7Yili Lou8College of Civil Engineering, Guizhou University, Guiyang 550025, ChinaCollege of Civil Engineering, Guizhou University, Guiyang 550025, ChinaSchool of Qilu Transportation, Shandong University, Jinan 250002, ChinaSchool of Qilu Transportation, Shandong University, Jinan 250002, ChinaSchool of Transportation Engineering, Shandong Jianzhu University, Jinan 250061, ChinaShandong University of Science and Technology, Qingdao 266590, Shandong, ChinaMining College, Guizhou University, Guiyang 550025, ChinaMining College, Guizhou University, Guiyang 550025, ChinaCollege of Civil Engineering, Guizhou University, Guiyang 550025, ChinaTo reveal the effect of confining pressure on the mechanical properties and rupture modes of quartz-bearing shale, the shale core of the no. 3 block of Fenggang, Guizhou Province, China, was analyzed by nuclear magnetic resonance, polarized light microscope thin section observation and identification, and core X-ray whole-rock minerals diffraction analysis to determine the distribution of shale minerals in the Niutitang Formation. On the microscale, based on digital image processing technology, this paper characterizes the nonuniformity of minerals in shale, a numerical model that can reflect the true microstructure of shale. Then, the failure process of shale under different confining pressures was simulated. The results show that when the shale is loaded with vertical displacement under different confining pressures, the compressive strength and elastic modulus of the sample change significantly. The failure mode can be roughly divided into three types: the inverted V-shaped (0 MPa, 2 MPa, and 4 MPa), V-shaped (6 MPa and 8 MPa), and inverted Z-shaped (10 MPa). Since the development of fractal theory provides a new space for studying the damage and fracture of rocks, the damage evolution and failure process of shale can also be regarded as the fractal process of cracks, in which the fractal dimension is the core parameter. The calculation is different under different stress levels. The fractal dimension under the condition of confining pressure shows that the value of the fractal dimension is greatly affected by the effect of confining pressure. When the fractal dimension is higher, the fracture mode is more complicated, and the internal damage degree is more serious. The research results provide important theoretical guidance for shale gas fracturing production.http://dx.doi.org/10.1155/2020/8819711 |
| spellingShingle | Hengtao Cui Zhonghu Wu Liping Li Jing Wang Shuguang Song Shangqu Sun Yujun Zuo Hao Liu Yili Lou Numerical Test Study of the Microscale Failure Modes and Fractal Analysis of Lower Cambrian Shale Based on Digital Images Advances in Civil Engineering |
| title | Numerical Test Study of the Microscale Failure Modes and Fractal Analysis of Lower Cambrian Shale Based on Digital Images |
| title_full | Numerical Test Study of the Microscale Failure Modes and Fractal Analysis of Lower Cambrian Shale Based on Digital Images |
| title_fullStr | Numerical Test Study of the Microscale Failure Modes and Fractal Analysis of Lower Cambrian Shale Based on Digital Images |
| title_full_unstemmed | Numerical Test Study of the Microscale Failure Modes and Fractal Analysis of Lower Cambrian Shale Based on Digital Images |
| title_short | Numerical Test Study of the Microscale Failure Modes and Fractal Analysis of Lower Cambrian Shale Based on Digital Images |
| title_sort | numerical test study of the microscale failure modes and fractal analysis of lower cambrian shale based on digital images |
| url | http://dx.doi.org/10.1155/2020/8819711 |
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