Velocity variations of Pand S-waves in sedimentary rock samples under thermobaric effects

The article describes studies into variation of propagation parameters of Pand S-waves in sedimentary rocks versus temperature, pressure and structural features. In the tests, samples from five groups of sedimentary rocks were subjected to uniaxial loading with simultaneous heating. At each stage of thermobaric treatment, ultrasonic Pand S-wave measurements were performed. Using the obtained data, the incremental velocities of elastic waves with increasing axial load were calculated, and the temperature effect on the increments was assessed. It is found that the increasing load results in the increased velocities of elastic waves proportionally with the porosity of the samples and inversely proportionally to the density of the samples. Heating elevates sensitivity of ultrasound parameters relative to the change in the axial pressure value. The spectrum analysis of the recorded signals reveals that the spectrum maximum shifts with increasing temperature, which is reflective of crack formation. The rate of cracking is higher in denser rocks. The resultant patterns can be used in development of efficient ultrasonic methods for the stress–strain monitoring in rock mass.

Nikolenko P. V., Shkuratnik V. L., Chepur M. D. Velocity variations of Pand S-waves in sedimentary rock samples under thermobaric effects. MIAB. Mining Inf. Anal. Bull. 2021;(7):5-13. [In Russ]. DOI: 10.25018/0236_1493_2021_7_0_5.

This work was financially supported by the Russian Foundation for Basic Research (Project No. 19-05-00152).

P.V. Nikolenko¹, Cand. Sci. (Eng.), Assistant Professor, e-mail: p.nikolenko@misis.ru,
V.L. Shkuratnik¹, Dr. Sci. (Eng.), Professor,
M.D. Chepur¹, Graduate Student, e-mail: chepur-1995@mail.ru,
¹ National University of Science and Technology «MISiS», 119049, Moscow, Russia.

P.V. Nikolenko, e-mail: p.nikolenko@misis.ru.

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