Geomechanical prediction of growth of brittle fracture zones in the vicinity of underground excavations in over-stress rock mass

Authors: Korchak P.A.

The theoretical and applied research data on formation of brittle fracture zones in over-stress rock mass are reviewed. The mathematical modeling of the related processes is discussed. It is shown how geomechanical processes develop up to formation of a brittle fracture zone. The latter can be described using the deformation models formulated within the theory ofplastic flow, with strength characteristics determined as functions of plastic strains of (hardening/softening law). Based on the mathematical modeling, prediction of brittle fracture zones at junctions of underground excavations of different geometry is implemented. It is found that the geometry of junctions and excavations has influence on the size of the brittle fracture zone. The relationships of change in the brittle fracture zone size versus effective stresses and characteristics of rock mass are generalized in the form of an analytical dependence. The research results are used in design of support systems for underground openings in over-stress rock mass (massive and weak or heavily jointed).

Keywords: rock, stress, brittle fracture, junction, underground excavation, geomechanical model.
For citation:

Korchak P. A. Geomechanical prediction of growth of brittle fracture zones in the vicinity of underground excavations in over-stress rock mass. MIAB. Mining Inf. Anal. Bull. 2021;(5):85-98. [In Russ]. DOI: 10.25018/0236_1493_2021_5_0_85.

Acknowledgements:
Issue number: 5
Year: 2021
Page number: 85-98
ISBN: 0236-1493
UDK: 622.831
DOI: 10.25018/0236_1493_2021_5_0_85
Article receipt date: 25.01.2019
Date of review receipt: 09.01.2021
Date of the editorial board′s decision on the article′s publishing: 10.04.2021
About authors:

P.A. Korchak, Head of the Forecast and Prevention of Mountain Impacts Service, Kirovsk Branch of Apatit, 184250, Kirovsk, Russia, e-mail: pkorchak@phosagro.ru.

 

For contacts:
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