TY - GEN
T1 - In situ rock stress measurement using an improved Downward Compact Conical-ended Borehole Overcoring technique
AU - Sakaguchi, K.
AU - Kizaki, Akihisa
AU - Matsuki, K.
PY - 2012/2/13
Y1 - 2012/2/13
N2 - Rock stress was measured in situ by an improved Downward Compact Conical-ended Borehole Overcoring (DCCBO) technique, which is a type of overcoring method, at Kamaishi mine to further promote the practical use of this technique. Prior to in situ stress measurement, a measuring apparatus (special conical bit, strain cell installation tool and data-logger with a built-in tilt/azimuth sensor) for an HQ-size borehole was developed by improving the apparatus used for a PQ-size borehole. A measurement method based on the determination of strain coefficients depending on the estimated elastic properties of an adhesive under the temperature measured in situ was then proposed. Through the use of in situ tests, we verified that this improved measuring apparatus for a HQ-size borehole works well in a water-filled vertical borehole. Moreover, the proposed measurement method could estimate in situ stresses relatively consistent with those obtained by other measurement methods near this test site. The results show that in situ stresses measured by the proposed measurement method are sufficiently reliable.
AB - Rock stress was measured in situ by an improved Downward Compact Conical-ended Borehole Overcoring (DCCBO) technique, which is a type of overcoring method, at Kamaishi mine to further promote the practical use of this technique. Prior to in situ stress measurement, a measuring apparatus (special conical bit, strain cell installation tool and data-logger with a built-in tilt/azimuth sensor) for an HQ-size borehole was developed by improving the apparatus used for a PQ-size borehole. A measurement method based on the determination of strain coefficients depending on the estimated elastic properties of an adhesive under the temperature measured in situ was then proposed. Through the use of in situ tests, we verified that this improved measuring apparatus for a HQ-size borehole works well in a water-filled vertical borehole. Moreover, the proposed measurement method could estimate in situ stresses relatively consistent with those obtained by other measurement methods near this test site. The results show that in situ stresses measured by the proposed measurement method are sufficiently reliable.
KW - Field measurements
KW - Lab testing
KW - Rock stress
UR - http://www.scopus.com/inward/record.url?scp=84856714031&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84856714031&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:84856714031
SN - 9780415804448
T3 - Harmonising Rock Engineering and the Environment - Proceedings of the 12th ISRM International Congress on Rock Mechanics
SP - 1101
EP - 1104
BT - Harmonising Rock Engineering and the Environment - Proceedings of the 12th ISRM International Congress on Rock Mechanics
T2 - 12th International Congress on Rock Mechanics of the International Society for Rock Mechanics, ISRM 2011
Y2 - 18 October 2011 through 21 October 2011
ER -