Abstract：his paper presents the general outline，approach，and procedure of application for numerical modelling methods in rock engineering practices. It is emphasized for numerical analysis to rely on engineering realization and engineering experience when using numerical method to solve engineering problems. An empirical approach is consequently introduced to reasonably estimating the mechanical properties of rock mass. It is also pointed out that the rock mass strengths are significantly underestimated in hydropower engineering practices in China when comparing to the corresponding rock mass properties from mining projects in Canada. Such underestimation is likely to lead to a misunderstanding of numerical modelling results. Additionally，the stress path analysis based on numerical simulations is recommended for the study on stress-induced rock mass problems whereas modelling the behaviour of geological structures is suggested when carrying out numerical investigations under low in-situ stress conditions. All suggestions for these two scenarios are illustrated with application cases of the Itasca program into numerical study of corresponding engineering concerns.
