ABSTRACT
Rock failure is intrinsically intertwined with heterogeneity and randomness. Although explicit and implicit numerical methods have been developed to consider rock heterogeneity, it is still challenging to characterise rock heterogeneity and model rock heterogeneous fracture. This paper developed an alternative method to model rock heterogeneity and fracture. A grid nanoindentation test is carried out to investigate the heterogeneous distribution of micromechanical properties of granite. Then, a random field model is developed based on the nanoindentation test results. The mean value, coefficient of variance and correlation length of the random field for the granite specimen are determined. Further, the random field model is embedded into the combined Finite and Discrete Element Method (FDEM). Heterogeneous numerical models for Semi-Circular Bend (SCB) tests with pre-existing cracks are developed to simulate mode-I and mixed-mode fractures of rock and verify the developed method. The heterogeneity can be characterized by random field very well.
