University of Oulu

Zhang, ZX., Gong, F., Kozlovskaya, E. et al. Characteristic Impedance and Its Applications to Rock and Mining Engineering. Rock Mech Rock Eng 56, 3139–3158 (2023).

Characteristic impedance and its applications to rock and mining engineering

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Author: Zhang, Zong-Xian1; Gong, Fengqiang2; Kozlovskaya, Elena1;
Organizations: 1Oulu Mining School, University of Oulu, Oulu, Finland
2School of Civil Engineering, Southeast University, Nanjing, China
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 3.1 MB)
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Language: English
Published: Springer Nature, 2023
Publish Date: 2023-11-03


The characteristic impedance of a rock is defined as the product of the sonic velocity and the density of the rock. Based on previous studies, this article finds that: (1) For an intact rock, its characteristic impedance is a comprehensive physical property, since it is closely related with strengths, fracture toughness, Young’s modulus, and Poisson’s ratio. (2) For rock masses, their characteristic impedances either increase markedly or slightly with increasing depth. (3) The bursts of intact rocks in laboratory are dependent on their characteristic impedances to a great extent, and strong rock bursts happen mostly in the rocks with large characteristic impedance. (4) Rock burst occurrence in tunnel and mines has a close relation with the characteristic impedances of the rocks. (5) Laboratory experiments on different rock samples show that seismic velocity increases as applied stress rises, and field monitored results from coal mines indicate that in the areas where rock bursts happened, the seismic velocity was increasing markedly before or during the bursts. (7) Drillability of rock depends on the characteristic impedance of the rock and the rock with larger impedance has lower drillability or lower penetration rate. (8) The potential applications of characteristic impedance include evaluation and classification of rock masses, and prediction of rock burst proneness and drillability.

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Series: Rock mechanics and rock engineering
ISSN: 0723-2632
ISSN-E: 1434-453X
ISSN-L: 0723-2632
Volume: 56
Issue: 4
Pages: 3139 - 3158
DOI: 10.1007/s00603-023-03216-3
Type of Publication: A1 Journal article – refereed
Field of Science: 218 Environmental engineering
1171 Geosciences
Funding: This study is financed by K. H. Renlund Foundation in Finland. Open Access funding provided by University of Oulu including Oulu University Hospital.
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