Abstract: In the carbonate belt of Tianxingzhou, Wuhan, there are giant thick-bedded arenated dolomites. Currently, there is no relevant experience or suggestion to determine its mechanical parameters. This study explores a method for determining the parameters of the Hoek-Brown (H-B) criterion for arenated dolomite using the linear transformation theory of the H-B and Mohr-Coulomb (M-C) criteria. It synthesizes previous research findings and conducts laboratory experiments. A simplified method was proposed to determine the upper limit of the maximum confining pressure σ_3max  by utilizing the static lateral pressure coefficient k₁. The mechanical parameters of sandy dolomite were estimated, and recommended values were provided based on the proposed method. The findings indicate that the proposed simplified method of σ_3max  based on k1 effectively narrows the range of confining pressure σ₃ and enhances accuracy. Additionally, the geological strength index GSI of sandy dolomite correlates linearly with the unconfined compressive strength σ_ci , leading to an improved table of suggested GSI values. The material parameter m_i is primarily influenced by rock type and fine-grained particle roughness, with m_i=9 in this study, showing small value range and minimal impact on rock mechanical parameters. Furthermore, the relationship between σ_ci and rock mass shear strength is established by converting the H-B and M-C criteria. These results provide valuable insights for applying the H-B criterion, effectively addressing the challenge of determining the mechanical parameters of highly fractured dolomite rocks. This research is significant for determining the mechanical parameters of rock formations similar to those in Wuhan, China.

Key words: arenated dolomite, Hoek-Brown failure criterion, geological strength index (GIS), mechanical parameters of rock mass