The Effect of Limestone Porosity on the Velocity of P- and S-Waves under Mechanical and Thermal Loading
P. V. Nikolenko, V. L. Shkuratnik, M. D. Chepur
National University of Science and Technology-MISIS, Moscow, 119049 Russia
Keywords: Rock, porosity, ultrasound, temperature, P-wave, S-wave, uniaxial load
Abstract
The thermal and mechanical tests of different porosity limestone show that an increase in the axial load results in the higher velocities of elastic waves while elevation of temperature decreases them. Higher temperatures act to raise velocities of P- and S-waves with increasing mechanical load, which enhances acoustic strain-sensitivity of rock. The spectral analysis of the recorded signals shows that higher temperature shifts spectrum maxima to lower frequency region. It is found that size of pores has influence on attenuation frequency of ultrasonic signals. The authors describe new approaches to acoustic strain-sensitivity control in rocks and to stress measurement reliability enhancement toward stability of underground structures.
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