Effect of shear-induced contact area and aperture variations on nonlinear flow behaviors in fractal rock fractures
This study experimentally analyzes the nonlinear flow characteristics and channelization of fluid through rough-walled fractures during the shear process using a shear-flow-visualization apparatus. A series of fluid flow and visualization tests is performed on four transparent fracture specimens wit...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2023-02-01
|
| Series: | Journal of Rock Mechanics and Geotechnical Engineering |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S1674775522001135 |
| _version_ | 1811171032256479232 |
|---|---|
| author | Changsheng Wang Richeng Liu Yujing Jiang Gang Wang Hengjie Luan |
| author_facet | Changsheng Wang Richeng Liu Yujing Jiang Gang Wang Hengjie Luan |
| author_sort | Changsheng Wang |
| collection | DOAJ |
| description | This study experimentally analyzes the nonlinear flow characteristics and channelization of fluid through rough-walled fractures during the shear process using a shear-flow-visualization apparatus. A series of fluid flow and visualization tests is performed on four transparent fracture specimens with various shear displacements of 1 mm, 3 mm, 5 mm, 7 mm and 10 mm under a normal stress of 0.5 MPa. Four granite fractures with different roughnesses are selected and quantified using variogram fractal dimensions. The obtained results show that the critical Reynolds number tends to increase with increasing shear displacement but decrease with increasing roughness of fracture surface. The flow paths are more tortuous at the beginning of shear because of the wide distribution of small contact spots. As the shear displacement continues to increase, preferential flow paths are more distinctly observed due to the decrease in the number of contact spots caused by shear dilation; yet the area of single contacts increases. Based on the experimental results, an empirical mathematical equation is proposed to quantify the critical Reynolds number using the contact area ratio and fractal dimension. |
| first_indexed | 2024-04-10T17:06:45Z |
| format | Article |
| id | doaj.art-e2463c75e0b84afab7b4f422db6fc504 |
| institution | Directory Open Access Journal |
| issn | 1674-7755 |
| language | English |
| last_indexed | 2024-04-10T17:06:45Z |
| publishDate | 2023-02-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Rock Mechanics and Geotechnical Engineering |
| spelling | doaj.art-e2463c75e0b84afab7b4f422db6fc5042023-02-06T04:05:51ZengElsevierJournal of Rock Mechanics and Geotechnical Engineering1674-77552023-02-01152309322Effect of shear-induced contact area and aperture variations on nonlinear flow behaviors in fractal rock fracturesChangsheng Wang0Richeng Liu1Yujing Jiang2Gang Wang3Hengjie Luan4Shandong Key Laboratory of Civil Engineering Disaster Prevention and Mitigation, Shandong University of Science and Technology, Qingdao, 266590, China; State Key Laboratory of Mining Disaster Prevention and Control Co-founded By Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, Qingdao, 266590, ChinaState Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou, 221116, ChinaState Key Laboratory of Mining Disaster Prevention and Control Co-founded By Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, Qingdao, 266590, China; School of Engineering, Nagasaki University, Nagasaki, 852-8521, Japan; Corresponding author. State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, Qingdao, 266590, China.Shandong Key Laboratory of Civil Engineering Disaster Prevention and Mitigation, Shandong University of Science and Technology, Qingdao, 266590, ChinaState Key Laboratory of Mining Disaster Prevention and Control Co-founded By Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, Qingdao, 266590, ChinaThis study experimentally analyzes the nonlinear flow characteristics and channelization of fluid through rough-walled fractures during the shear process using a shear-flow-visualization apparatus. A series of fluid flow and visualization tests is performed on four transparent fracture specimens with various shear displacements of 1 mm, 3 mm, 5 mm, 7 mm and 10 mm under a normal stress of 0.5 MPa. Four granite fractures with different roughnesses are selected and quantified using variogram fractal dimensions. The obtained results show that the critical Reynolds number tends to increase with increasing shear displacement but decrease with increasing roughness of fracture surface. The flow paths are more tortuous at the beginning of shear because of the wide distribution of small contact spots. As the shear displacement continues to increase, preferential flow paths are more distinctly observed due to the decrease in the number of contact spots caused by shear dilation; yet the area of single contacts increases. Based on the experimental results, an empirical mathematical equation is proposed to quantify the critical Reynolds number using the contact area ratio and fractal dimension.http://www.sciencedirect.com/science/article/pii/S1674775522001135FractureShear displacementFractal dimensionNonlinear flowContact areaFlow visualization |
| spellingShingle | Changsheng Wang Richeng Liu Yujing Jiang Gang Wang Hengjie Luan Effect of shear-induced contact area and aperture variations on nonlinear flow behaviors in fractal rock fractures Journal of Rock Mechanics and Geotechnical Engineering Fracture Shear displacement Fractal dimension Nonlinear flow Contact area Flow visualization |
| title | Effect of shear-induced contact area and aperture variations on nonlinear flow behaviors in fractal rock fractures |
| title_full | Effect of shear-induced contact area and aperture variations on nonlinear flow behaviors in fractal rock fractures |
| title_fullStr | Effect of shear-induced contact area and aperture variations on nonlinear flow behaviors in fractal rock fractures |
| title_full_unstemmed | Effect of shear-induced contact area and aperture variations on nonlinear flow behaviors in fractal rock fractures |
| title_short | Effect of shear-induced contact area and aperture variations on nonlinear flow behaviors in fractal rock fractures |
| title_sort | effect of shear induced contact area and aperture variations on nonlinear flow behaviors in fractal rock fractures |
| topic | Fracture Shear displacement Fractal dimension Nonlinear flow Contact area Flow visualization |
| url | http://www.sciencedirect.com/science/article/pii/S1674775522001135 |
| work_keys_str_mv | AT changshengwang effectofshearinducedcontactareaandaperturevariationsonnonlinearflowbehaviorsinfractalrockfractures AT richengliu effectofshearinducedcontactareaandaperturevariationsonnonlinearflowbehaviorsinfractalrockfractures AT yujingjiang effectofshearinducedcontactareaandaperturevariationsonnonlinearflowbehaviorsinfractalrockfractures AT gangwang effectofshearinducedcontactareaandaperturevariationsonnonlinearflowbehaviorsinfractalrockfractures AT hengjieluan effectofshearinducedcontactareaandaperturevariationsonnonlinearflowbehaviorsinfractalrockfractures |