Comparative analysis of two failure criteria for rocks and massifs

Shashenko, O. M.; Kovrov, O. S.

Purpose. The analysis of two failure criteria for rocks being in the stress-strain state. Methodology. The study is based on an integrated approach with the use of analysis and synthesis of the literature sources on the topic related to failure of the rocks with heterogeneous structure, and use of analytical and empirical failure criteria to assess the strength of rocks. Findings. The analysis of the two failure criteria for compliance with the results of laboratory testing of rocks in the volumetric stressed state is carried out. It is established that the expressions of both analytical criteria reflect the process of rock failure by introducing factors that take into account the mining and geological conditions and mining technology: in the Hoek - Brown criterion - m_b, s, a, D, GSI; in the O. M. Shashenko criterion - ψ, η₀, l_t. Both criteria meet the results of laboratory tests provided mi coefficient from the Hoek - Brown analytical expression, which takes into consideration rock structure and genesis, should not exceed 4 (m_i = 4). Originality. Analytical comparison of two criteria has shown that, taking into consideration scattering experimental points obtained as a result of laboratory testing of rocks in the volumetric stressed state when 0 = m_i = 4,0, they reflect the fact of the destruction of structurally inhomogeneous rock quite well. However, the Hoek - Brown criterion does not fully take into account the components of the spherical stress tensor (σ₁ + σ₃) and if the m_i > 4 its application requires additional study. Practical value. Comparison of the analytical criterion with the results of laboratory testing of structurally heterogeneous materials in the volumetric stressed state allows predicting the rock failure in the massif with the precision of 94 %.


	Наукова періодика України		Naukovyi visnyk Natsionalnoho Hirnychoho Universytetu