Recommended rock joints setting in 2D FEM simulations for engineering design of excavations created in jointed rockmass

Abstract

ABSTRACT Numerical modelling has became one of the most widely used design tools for evaluation of engineering responses in ground and support measures around excavations. Proper model setup for numerical analysis is important, especially for excavations created in blocky and massive rockmasses by including rock joints network in the model. Characterisation of rock joint such as spacing, length, persistent and shear strength may have a large influence on the mechanical behaviours of rockmass in terms of strength and deformation in rock engineering problems. Overview the current practice, no appropriate guidance is given assistant in setting up rock joints network in model for jointed rockmass analysis. To fill this gap, a recommended rock joints setting for a range of rockmass qualities in model analysis is proposed based on a comprehensive literature review on rock joints studies. Verification of the recommended rock joints setting is performed that two published case examples are used to examine the disparity in rock joints setting in the model and checked against the difference between the modelled results and as-constructed monitoring records. The verification demonstrates that a close agreement between the model result and as-constructed monitoring record could be obtained to minimise any potential over- or under-design practice.