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dc.contributor.authorKang, S
dc.contributor.authorKim, J
dc.contributor.authorNoh, J
dc.contributor.authorNa, T
dc.contributor.authorJang, Hyong Doo
dc.contributor.authorKo, C
dc.date.accessioned2017-04-28T13:59:57Z
dc.date.available2017-04-28T13:59:57Z
dc.date.created2017-04-28T09:06:08Z
dc.date.issued2017
dc.identifier.citationKang, S and Kim, J and Noh, J and Na, T and Jang, H.D. and Ko, C 2017. Evaluation of the State of Rocks in Load Steps by Low-frequency Ultrasonic Flaw Detection. The Journal of Engineering Geology. 27 (1): pp. 51-58.
dc.identifier.urihttp://hdl.handle.net/20.500.11937/52813
dc.identifier.doi10.9720/kseg.2017.1.51
dc.description.abstract

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.

dc.publisherThe Korean Society of Engineering Geology
dc.titleEvaluation of the State of Rocks in Load Steps by Low-frequency Ultrasonic Flaw Detection
dc.typeJournal Article
dcterms.source.volume27
dcterms.source.number1
dcterms.source.startPage51
dcterms.source.endPage58
dcterms.source.issn1226-5268
dcterms.source.titleThe Journal of Engineering Geology
curtin.departmentDept of Mining Eng & Metallurgical Eng
curtin.accessStatusOpen access via publisher
curtin.contributor.orcidJang, Hyong Doo [0000-0002-3978-5840]


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