Evaluation of the State of Rocks in Load Steps by Low-frequency Ultrasonic Flaw Detection
The purpose of this study was to quantitatively evaluate the state of rocks in load steps by using the low-frequency ultrasonic flaw detection method. The initial Vp-velocities measured with a CND tester were in the order of Z-axis < X-axis < Y-axis, with 1687.5 m/s along the X-axis, 1...
| Main Authors: | , , , , , |
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| Format: | Journal Article |
| Published: |
The Korean Society of Engineering Geology
2017
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| Online Access: | http://hdl.handle.net/20.500.11937/52813 |
| _version_ | 1848759017498738688 |
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| author | Kang, S Kim, J Noh, J Na, T Jang, Hyong Doo Ko, C |
| author_facet | Kang, S Kim, J Noh, J Na, T Jang, Hyong Doo Ko, C |
| author_sort | Kang, S |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | The purpose of this study was to quantitatively evaluate the state of rocks in load steps by using the low-frequency ultrasonic flaw detection method. The initial Vp-velocities measured with a CND tester were in the order of Z-axis < X-axis < Y-axis, with 1687.5 m/s along the X-axis, 1690.7 m/s along the Y-axis, 1548.3 m/s along the Z-axis, and an average of 1642.2 m/s. The overall average of the Q vlaues, measured with a Silver Schmidt hammer, was 62.6, which corresponds to a uniaxial compressive strength of ~105 MPa. The Vp-velocity, measured with a low-frequency ultrasonic flaw detector at load steps of 50%, 60%, 70%, and 80%, typically decreases in the order of X-axis < Y-axis < Z-axis with increasing load steps. This order contrasts with that of the initial Vp-velocities. As the load step increases the factors that reduce the Vp-velocity in the X-axis direction are more influential than those in the Y-axis or Z-axis directions. This indicates that the initial state of rocks can vary and is dependent on the stress state. |
| first_indexed | 2025-11-14T09:53:12Z |
| format | Journal Article |
| id | curtin-20.500.11937-52813 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T09:53:12Z |
| publishDate | 2017 |
| publisher | The Korean Society of Engineering Geology |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-528132020-09-07T05:38:10Z Evaluation of the State of Rocks in Load Steps by Low-frequency Ultrasonic Flaw Detection Kang, S Kim, J Noh, J Na, T Jang, Hyong Doo Ko, C The purpose of this study was to quantitatively evaluate the state of rocks in load steps by using the low-frequency ultrasonic flaw detection method. The initial Vp-velocities measured with a CND tester were in the order of Z-axis < X-axis < Y-axis, with 1687.5 m/s along the X-axis, 1690.7 m/s along the Y-axis, 1548.3 m/s along the Z-axis, and an average of 1642.2 m/s. The overall average of the Q vlaues, measured with a Silver Schmidt hammer, was 62.6, which corresponds to a uniaxial compressive strength of ~105 MPa. The Vp-velocity, measured with a low-frequency ultrasonic flaw detector at load steps of 50%, 60%, 70%, and 80%, typically decreases in the order of X-axis < Y-axis < Z-axis with increasing load steps. This order contrasts with that of the initial Vp-velocities. As the load step increases the factors that reduce the Vp-velocity in the X-axis direction are more influential than those in the Y-axis or Z-axis directions. This indicates that the initial state of rocks can vary and is dependent on the stress state. 2017 Journal Article http://hdl.handle.net/20.500.11937/52813 10.9720/kseg.2017.1.51 The Korean Society of Engineering Geology unknown |
| spellingShingle | Kang, S Kim, J Noh, J Na, T Jang, Hyong Doo Ko, C Evaluation of the State of Rocks in Load Steps by Low-frequency Ultrasonic Flaw Detection |
| title | Evaluation of the State of Rocks in Load Steps by Low-frequency Ultrasonic Flaw Detection |
| title_full | Evaluation of the State of Rocks in Load Steps by Low-frequency Ultrasonic Flaw Detection |
| title_fullStr | Evaluation of the State of Rocks in Load Steps by Low-frequency Ultrasonic Flaw Detection |
| title_full_unstemmed | Evaluation of the State of Rocks in Load Steps by Low-frequency Ultrasonic Flaw Detection |
| title_short | Evaluation of the State of Rocks in Load Steps by Low-frequency Ultrasonic Flaw Detection |
| title_sort | evaluation of the state of rocks in load steps by low-frequency ultrasonic flaw detection |
| url | http://hdl.handle.net/20.500.11937/52813 |