A novel method for modelling the existence of fault fracture zones within 3D weathered rock slopes

High-steep weathered rock slopes are often encountered in vicinity of the large-scale hydropower engineering projects. A variety of fault fracture zones may exist inside the weathered rock mass due to the complexity of geological activities. However, few publications have considered the state of fault fracture zones within a rock slope in a realistic way. For this goal, this study proposes a new approach to modelling the existence of fault fracture zones inside rock slopes based on 3D Gaussian random field, in which the basic features of fault fracture zones can be well established in terms of the need of site conditions. The results demonstrate that the inclination of week fractured zones has pronounced effects on the development of the failure mode of a rock slope. The degree of connectivity of the resultant irregular slip surfaces at each cross section of the 3D model significantly affects the system stability of a weathered slope. In addition, using a 3D numerical model for the analysis of a fractured slope gives a more reasonable and reliable estimation of the slope stability than the 2D one. The presented results can offer a new insight for the stability investigations of weathered rock slopes with fault fracture zones, aiming to reduce the risk of landslides.