Multicomponent strain gauges for assessing the stress-strain state of a rock mass

The level of the current state of mining geomechanics is largely due to the widespread use of numerical simulation implemented in various software packages such as 3DEC, FLAG3D, SIMULIA ABAQUS, MAP3D, RS3, Elfen, EXAMINE 3D and others. The most important condition for carrying out correct numerical modeling and the choice on its basis of the correct measures to ensure the steady state of workings is the magnitude and direction of the main stresses (stress tensor). Knowledge of the stress tensor can be considered as a base point on which further numerical studies are built, and as a marker that controls the results of numerical simulation. Based on the analysis of existing methods of end unloading (Overcoring), the paper formulates the fundamental provisions on the basis of which a hardware-software complex was created for assessing the stress-strain state (SSS) of a rock mass. The main element of the complex is a multicomponent strain gauge. The proposed design of the sensor makes it possible to obtain the full strain tensor at the critical points of the massiv. The main provisions of the methodology for conducting field work on the assessment of SSS using the developed equipment are considered. The proposed technique has been tested at 4 fields of the Russian Federation. It should be noted, that the developed multicomponent strain gauge could be use to create modern deformation monitoring systems, which, together with existing monitoring systems (seismic, acoustic) and local control methods, significantly increase the safety of mining operations.

Morozov K. V., Demekhin D. N., Bakhtin E. V. Multicomponent strain gauges for assessing the stress-strain state of a rock mass. MIAB. Mining Inf. Anal. Bull. 2022;(6−2):80—97. [In Russ]. DOI: 10.25018/0236_1493_2022_62_0_80.

Morozov K. V.¹, Head of the Laboratory of Geomechanics, Scientific Center for Geomechanics and Mining, https://orcid.org/ 0000-0003-3597-756X, e-mail: morozov_kv@pers.spmi.ru;
Demekhin D.N.¹, Senior Researcher, Laboratory of Geomechanics, Scientific Center for Geomechanics and Mining, https://orcid.org/0000-0001-7958-2290, e-mail: demyokhin_dn@pers.spmi.ru;
Bahtin E. V.¹, Leading Engineer, Laboratory of Geomechanics, Scientific Center for Geomechanics and Mining, e-mail: bahtin_ev@pers.spmi.ru;
¹ Saint Petersburg Mining University, 2, 21st Line, St. Petersburg,199106, Russia.

Morozov K. V., e-mail: morozov_kv@pers.spmi.ru

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