Abstract: Based on the Hertz-Mindlin with bonding (HMB) contact model in EDEM, the modeling method of the rock discrete element model was investigated. First of all, all of the bonds in HMB rock model must be “weak bond”, i.e., the tensile strength of the bond is less than its critical normal stress. Then, the regression relationships between the elastic modulus , Poisson’s ratio , tensile strength of rock model and the particle and bond parameters were established, respectively. According to the three regression relationships, a mathematical model that can fit the real-rock’s E, , and through the HMB model was proposed. For the compressive strength of rock, when the critical stress ratio ( = / , is critical normal stress, and is critical tangential stress) ranges from 1 to 2, is influenced by , and the ratio of critical normal to tangential stress. Especially, when the is closed to 1.5, the failure mode of the rock model presents a better agreement with the experiment result. In addition, when the is constant, a linear relationship between the and can be clearly observed. In conclusion, a HMB model based modeling method that can fit the elastic modulus, Poisson’s ratio, tensile strength, compressive strength and the failure form of rock sample was proposed, and the detail steps were also given. Finally, an example was conducted to verify the proposed modeling method. The results showed that the rock models established through the proposed method can fit both the static and dynamic mechanical properties of rock.

Key words: rock, multi-parameters, fitting, modeling