Inclusion of rock mass fracturing in determination of in situ stress state by overcoring using multi-component displacement sensor

Mining is a complex process, one of the main stages of which is excavation operations. Increasing their safety is based on the implementation of a geomechanical prediction, the degree of reliability of which is largely determined by engineering surveys. In their implementation, a special place is occupied by methods for assessing the in situ stress state of the rock mass, based on drilling exploratory boreholes in the rock mass with the subsequent installation of high-precision measuring equipment for in-situ observations. This paper proposes an approach to taking into account the disturbance of the rock mass when determining its in situ stress state using the overcoring method with a multicomponent displacement sensor. Various fracturing parameters are considered: crack inclination angles relative to the longitudinal axis of the measuring borehole and the crack opening width, which is necessary for the correct determination of the properties of their elastic response. 3D numerical models reflecting the main technological stages of field tests are proposed. An approach to determining the effective deformation and strength properties of a fractured rock mass is described, taking into account its heterogeneity and anisotropy.

Belyakov N. A., Emelyanov I. A. Inclusion of rock mass fracturing in determination of in situ stress state by overcoring using multi-component displacement sensor. MIAB. Mining Inf. Anal. Bull. 2024;(12-1):145-164. [In Russ]. DOI: 10.25018/0236_1493_2024_ 121_0_145.

The study was supported by the Russian Science Foundation, Project No. 23-17-00144.

N.A. Belyakov¹, Cand. Sci. (Eng.), Associate Professor, e-mail: Belyakov_NA@pers.spmi.ru, ORCID ID: 0000-0002-9754-501X,
I.A. Emelyanov¹, Graduate Student, e-mail: Emelyanov_IA@pers.spmi.ru, ORCID ID: 0000-0002-8515-3629,
¹ Empress Catherine II Saint-Petersburg Mining University, 199106, Saint-Petersburg, Russia.

I.A. Emelyanov, e-mail: Emelyanov_IA@pers.spmi.ru.

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