USING ACOUSTIC EMISSION PHENOMENA IN COMPOSITES FOR THE STRESS-STRAIN ANALYSIS OF ROCKS SURROUNDING AN UNDERGROUND EXCAVATION

The article substantiates the methods for the dynamic stress–strain analysis of rocks around an underground excavation based on emission phenomena in composite materials. The detailed requirements to the acoustic properties of such composites, including strain sensitivity for acoustic emission, are presented. Strain sensitivities of some composites and rocks are compared. The new efficient algorithm of censoring proposed in the article includes ultrasonic scanning of composites and correlation processing of recorded noise pulses. The algorithm enables revealing structural defects undetectable using conventional time–impulse methods. The scope of the article also encompasses the methods and equipment for monitoring temporal variation in such parameters as distance between the abutment pressure zone and the excavation boundary, or major principal stress increment in the abutment pressure zone. It is emphasized that the proposed methods are applicable for warning when the mentioned parameters exceed the preset critical levels characterizing instability of underground excavations.


The study was supported by the Russian Science Foundation, Project No. 17-77-10009.

Keywords

Kaiser effect, stress–strain analysis, rock mass, control, ultrasound, censoring.

Issue number: 12
Year: 2018
ISBN:
UDK: 622.02:539.2
DOI: 10.25018/0236-1493-2018-12-0-134-141
Authors: Nikolenko P. V., Chepur M. D.

About authors: Nikolenko P.V., Candidate of Technical Sciences, Assistant Professor, Chepur M.D., Student, Mining Institute, National University of Science and Technology «MISiS», 119049, Moscow, Russia, e-mail: ftkp@mail.ru.

REFERENCES:

1. Baklashov I. V. Geomekhanika. T.1. Osnovy geomekhaniki [Geomechanics. Vol. 1. Fundamentals of geomechanics], Moscow, MGGU, 2004, 208 p.

2. Shkuratnik V. L., Nikolenko P. V. Metody opredeleniya napryazhenno-deformirovannogo sostoyaniya massiva gornykh porod [Methods of stress–strain analysis of rock mass], Moscow, MGGU, 2012, 113 p.

3. Espada M., Lamas L. Back Analysis Procedure for Identification of Anisotropic Elastic Parameters of Overcored Rock Specimens. Rock Mechanics and Rock Engineering, 2017, Vol. 50, Issue 3, Pp. 513—527.

4. Petr W., Lubomir S., Jan N., Petr K., Tomas K. Determination of stress state in rock mass using strain gauge probes CCBO. Procedia Engineering, 2016, Vol. 149, Pp. 544—552.

5. Ogil'vi A. A. Osnovy inzhenernoy geofiziki [Fundamentals of engineering geophysics], Moscow, Nedra, 1990, 501 p.

6. Li Q., He J.-J., Li C.-X. Relationship between the ultrasonic velocities and strata pressure of the coalbed methane reservoir in qinshui basin by rock physical testing. Wutan Huatan Jisuan Jishu, 2013, Vol. 35, Iss. 4, pp. 382—386.

7. Nikolenko P. V.Shkuratnik V. L. Acoustic emission in composites and applications for stress monitoring in rock masses. Journal of Mining Science, 2014, Vol. 50, Issue 6, Pp. 1088—1093.

8. Shkuratnik V. L.Nikolenko P. V.Kormnov A. A. Change in the correlation characteristics of acoustic noise in sonic testing of rocks under uniaxial mechanical loading. Gornyi Zhurnal, 2016, Vol. 2016, Issue 6, Pp. 60—63.

9. Lavrov A. The Kaiser effect in rocks: Principles and stress estimation techniques, International. Journal of Rock Mechanics and Mining Sciences, 2003, Vol. 40, Issue 2, pp. 151—171.

10. Li C. A theory for the Kaiser effect and its potential applications. Proc. 6th Conf. AE/MA in Geologic Structures and Materials. Clausthal-Zellerfeld, Trans Tech Publications, 1998, Pp. 171—185.

11. Holcomb D. J.Costin L. S. Detecting damage surfaces in brittle materials using acoustic emissions. Journ. Appl. Mech. Trans. ASME, 1986, Vol. 53, No. 3, Pp. 536—544.

12. Shkuratnik V. L., Lavrov A. V. Effekt Kayzera v gornykh porodakh, ispytavshikh trekhosnoe nagruzhenie [Kaiser effect in rocks subjected to triaxial compression]. Fiziko-tekhnicheskiye problemy razrabotki poleznykh iskopayemykh. 2002, no 1, pp. 52—61. [In Russ].

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