Laboratory measurement of elastic anisotropy on spherical rock samples by longitudinal and transverse sounding under confining pressure

0435076 - GLÚ 2016 RIV NL eng J - Journal Article
Lokajíček, Tomáš - Svitek, Tomáš
Laboratory measurement of elastic anisotropy on spherical rock samples by longitudinal and transverse sounding under confining pressure.
Ultrasonics. Roč. 56, February 2015 (2015), s. 294-302. ISSN 0041-624X. E-ISSN 1874-9968
R&D Projects: GA MŠMT LH13102; GA ČR GAP104/12/0915; GA ČR GA13-13967S
Institutional support: RVO:67985831
Keywords : elastic anisotropy * hydrostatic pressure * ultrasonic sounding * high pressure * longitudinal and shear waves
Subject RIV: DB - Geology ; Mineralogy
Impact factor: 1.954, year: 2015

Knowledge of shear wave velocities in loaded rocks is important in describing elastic anisotropy. A new high-pressure measuring head was designed and constructed for longitudinal and traversal ultrasonic sounding of spherical rock samples in 132 independent directions under hydrostatic pressure up to 60 MPa. The velocity is measured using a pair of P-wave sensors and two pairs of S-wave sensors (T V /R V and T H /R H ) with perpendicular polarization. An isotropic glass sphere was used to calibrate the experimental setup. A fine-grained anisotropic quartzite sample was examined using the P- and S-wave ultrasonic sounding. Waveforms are recorded by pairs of T P /R P ,T V /R V and T H /R H transducers in a range of confining pressure between 0.1 and 60 MPa. The recorded data showed a shear wave splitting in three basic structural directions of the sample. The measurements proved to be useful in investigating oriented micro-cracks, lattice (LPO) and shape-preferred orientation (SPO) for the bulk elastic anisotropy of aniso- tropic rocks subjected to hydrostatic pressure.
Permanent Link: http://hdl.handle.net/11104/0239672