An accurate determination of Hoek–Brown constant m_i is of great significance in the estimation of the failure criteria of brittle rock materials. So far, different approaches such as rigidity index method (R-index), uniaxial compressive strength-based method, and tensile strength-based method, and the combination of these two methods (combination based method) have been proposed to calculate the value of m_i. This paper aims to thoroughly review the previously existing methods to calculate the value of m_i and make comparison between the obtain results to propose the new material constants that provide the best fit with the experimental data. In order to fulfill this goal, a large number of data for different quasi-isotropic intact rock types from the literature were collected and statistically analyzed. Additionally, based on rock types, new material constants are introduced for igneous, sedimentary, and metamorphic rocks. The obtained results proves that for different rock groups (igneous, sedimentary, and metamorphic rocks), R-index method provides the best fit with the experimental data among the others, and it is also independent of rock type. Interestingly enough, there is significant differences in the predicted m_i values using different methods, which is more probably due to the quantity and quality of data used in the statistical analysis.

Hoek-Brown 常数m _i的准确确定对于脆性岩石材料破坏准则的估计具有重要意义。迄今为止，已经提出了不同的方法，例如刚度指数法（R-index）、基于单轴抗压强度的方法和基于抗拉强度的方法，以及这两种方法的组合（基于组合的方法）来计算中号_我。本文旨在彻底回顾以前存在的计算m _i值的方法。并对获得的结果进行比较，以提出与实验数据最吻合的新材料常数。为了实现这一目标，从文献中收集了大量不同准各向同性完整岩石类型的数据并进行了统计分析。此外，根据岩石类型，为火成岩、沉积岩和变质岩引入了新的材料常数。得到的结果证明，对于不同的岩石群（火成岩、沉积岩和变质岩），R-index 方法与实验数据拟合最好，并且与岩石类型无关。有趣的是，预测的m _i存在显着差异 值使用不同的方法，这更可能是由于统计分析中使用的数据的数量和质量。