Stability analysis of vertical excavations in hard rock by integrating a fracture system into a PFC model

Abstract

This paper presents an implementation of a comprehensive engineering approach to the analysis of the stability of vertical excavations in rock. This approach relies in the generation of discrete fracture systems to better capture the structural complexity of the rock mass. The resulting fracture system is consequently linked into a distinct element stress analysis. The particle flow code was selected as it potentially allows greater flexibility in representing a fracture system. In the first example a 3D fracture system was linked into a 2D PFC model. Although this has allowed for an improved quantification of stress structure interaction it necessitated important simplifications which may not be necessarily appropriate. These have been overcome by providing a complete integration of a 3D fracture system to a 3D PFC model. This will potentially lead into a design tool that adequately account for the stress structure interaction on the stability of vertical or near vertical excavations in hard rock.