Experimental studies into temperature and pressure effect on the quality and fracture of rock samples

Quality of rocks can be affected by many factors. The critical factors are the temperature and stress state. One of the approaches to the in-situ estimation of rock quality is investigation of acoustic properties of rocks, in particular, measurement of Pand S-wave velocities. This article studies dynamics of damage accumulation in limestone samples of different porosity under the action of varied temperatures and pressures. Computer-assisted modeling proves detectability of moment of thermal equilibrium between the faces and center of a sample by flattening of the P-wave velocity curve. The modeling results are compared with the real experimental data. The laboratory-scale tests on a specially designed installation have found that the increasing temperature causes a more intense growth in the amount of damage in porous limestone samples than in less-porous limestone. Alternatively, the increase in the axial pressure reduces intensity of damage process. With increasing axial pressure to 9 MPa, the increment in the amount of damages is reduced in massive and porous limestone by 24% and 48%, respectively, at the temperature being risen from 20 to 100 °С.

Nikolenko P. V. Experimental studies into temperature and pressure effect on the quality and fracture of rock samples. MIAB. Mining Inf. Anal. Bull. 2020;(11):70-78. [In Russ]. DOI: 10.25018/0236-1493-2020-11-0-70-78.

The study was supported by the Russian Foundation for Basic Research, Grant No. 19-05-00152.

P.V. Nikolenko, Cand. Sci. (Eng.), Assistant Professor, e-mail: p.nikolenko@misis.ru, National University of Science and Technology «MISiS», 119049, Moscow, Russia.

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