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Muroran-IT Academic Resources Archive >
30 情報工学科 = Department of Computer Science and Systems Engineering >
30a 雑誌掲載論文 >
| タイトル: | Dispersion analysis of crack-waves in an artificial subsurface fracture using two crack models |
| 著者: | Nagano, Koji
Niitsuma, Hiroaki
永野, 宏治 |
| キーワード: | crack
crack-waves
dispersion
wavelet |
| Issue Date: | Jan-2000 |
| 出版者: | IEEE |
| 引用: | IEEE Transactions on geoscience and remote sensing, 38(1), pp.3-11, 2000. |
| 抄録: | The authors investigated crack-wave dispersions in an artificial subsurface fracture both experimentally and numerically using a wavelet analysis and two crack models. Crack-waves are seismic modes that propagate along a fracture. The dispersion characteristics of crack-waves depend on the geometry and physical properties of a fracture. The authors measured crack-waves at an artificial subsurface fracture in Higashi-Hachimantai Hot Dry Rock model field, Japan. This subsurface fracture is at a depth of about 370 m. During a measurement, they injected water into the fracture and changed the interface conditions of the fracture. A wavelet analysis provided the dispersion of the arrival times of crack-waves. The crack-waves showed positive velocity dispersion; i.e., low frequency components arrived later. As wellhead pressure increased due to water injection, the dispersion characteristics changed. A low-velocity-layer (LVL) model and a crack-stiffness model were examined to explain crack-wave dispersion. In the LVL model, rock layers with a low velocity surround a fluid layer. There is no contact between the LVLs. On the other hand, the crack-stiffness model considers crack stiffness due to contact between asperities on fracture surfaces. The arrival-time curves calculated by the crack-stiffness model showed a good fit to the measured values. As wellhead pressure increased, crack stiffness decreased and thickness of a fluid layer increased. In contrast, the LVL model did not adequately duplicate the measured data |
| URI: | http://hdl.handle.net/10258/200 |
| ISSN: | 0196-2892 |
| Rights: | (c)2000 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.
IEEE Transactions on geoscience and remote sensing , vol. 38, issue 1, 2000, pp. 3-11 |
| DOI: | 10.1109/36.823896 |
| Appears in Collections: | 30a 雑誌掲載論文
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http://hdl.handle.net/10258/200
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