Measuring In situ Rock Stress by means of the Compact Conical-ended Borehole Over-coring (CCBO) Technique
Compact conical-ended borehole overcoring (CCBO) is proposed for in situ rock stress measurement applicable to the faulted and highly jointed rock formations. Apparatus and operating procedure are described in detail. The observation equation on the stress tensor to be used in practice is presented, along with the possible ways for representing and interpreting the results. Thus, it is stated how the three dimensional state of in situ rock stress is determined from the strains on the conical end surface of a single borehole. The error in stress and stresses in an isotropic or transversely isotropic rock mass are obtained. Additionally, the reliability and the applicability of the present technique is successfully verified from the case studies.
- Memoirs of the Faculty of Engineering, Kumamoto University
Memoirs of the Faculty of Engineering, Kumamoto University 43 (2), 19-35, 1998-11-30