ABOUT ROCK STRENGTH CERTIFICATE

Year 2020, Volume: 4 Issue: 5, 18 - 31, 28.12.2020

Boris Rychkov Nikita Komartsov Margarita Kulagina

Abstract

The stress state of rocks in the massif is modeled by
testing standard cylindrical specimens on equipment according to the Karman’s
scheme, when some the ratio between the axial compressive stress and the
principal stresses from uniform lateral pressure is given. In this case their
ratio at the time of destruction indicates the strength of rocks. These stresses
can take many values, and it is impossible to carry out the whole complex of
experiments with different ratios of these components. Therefore, various
methods of calculation are being developed, which can be used to estimate the
degree of danger of the stress state by the postulated dependencies between the
main stresses, i.e. to predict the strength properties of materials at the
moment of destruction.

The envelope of limit stress circles on the Mohr’s
diagram in the coordinates “normal stress - shear stress” is considered as the
rock strength certificate. To construct the envelope was used the relationship
between the maximum and minimum principal stresses, presented in the form of
two different strength criteria. One of them is the well-known criterion of
Hoek-Brown, the other is proposed recently by T.B. Duyshenaliev and K. T.
Koichumanov. The applicability of these criteria was checked on A.N.
Stavrogin's and K. Mogi's experimental data, which were received by testing
cylindrical specimens of various rocks under triaxial compression, as well as in
the case of uniaxial tension.

Keywords

rock strength, envelope of limit stress circles, strength criterion, principal stresses, Mohr’s diagram

References

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