Modification of Hoek-Brown Criterion and Its Application Based on Fuzzy Synthetic Evaluation

摘要

The importance of mechanical parameters of rock mass is presented, and some methods to determine these mechanical parameters are introduced, whereas its accuracy is questionable and controversial. As there is difficulty in determining the disturbance factor D relayed on the Hoek-Brown strength criteria, fuzzy comprehensive evaluation is employed. Considering the factors influencing on disturbance and relevant engineering experience, the calculation of the value of D is 0.9379, which is more corresponded to the actual situation. Additionally, the rationality, that the bounds characterized by slip surface for dividing disturbed and undisturbed zone, was discussed and it overcome deficiency of other expressions. Relayed on mechanical parameters of rock mass from Liberia Bone Iron Mine, calculation of the factor D was presented by means of the modified parameters and other methods respectively. On the basis of the comparative analysis, the results showed that the former was more suitable to mirror the disturbance degree in-suit. What's more, it verified the reasonability and significance of partition of disturbed and non-disturbed zone and provided important reference in the future research.