Integration of automatic discontinuity identification and multi-scale hierarchical modeling for stability analysis of highly-jointed rock slopes

The geometric shape of the slope and the distribution characteristics of the complex fracture system significantly impact the stability of highly-jointed rock slopes. Constructing an accurate three-dimensional (3D) geological model is crucial for the 3D stability analysis of these slopes. However, the numerous minor discontinuities in rock slopes complicate model construction and reduce computational efficiency. This paper proposes a stability-analysis method for highly-jointed rock slopes that integrates automatic identification of real discontinuities with hierarchical modeling of 3D multi-scale fracture networks. Real discontinuity information was automatically extracted using a developed fuzzy k-means clustering algorithm, which calculated the number of dominant discontinuity sets and their spatial distribution laws. The Monte Carlo stochastic method was then employed to generate a complex 3D fracture-network system with statistical characteristics identical to those of the real discontinuities. The multi-scale fracture network was classified based on trace length. Given the numerous minor discontinuities that significantly impact computational efficiency, synthetic rock mass technology was utilized to determine the representative elementary volume with equivalent rock-mass characteristics to reasonably generalise the geological engineering model of rock slopes with complex fractures. In applying the slope-excavation stability analysis and evaluation to the Feishuiyan rock slope, the method achieved high automation in contactless scanning, efficient identification of discontinuity effects, accurate model calculations, and reliable stability analysis during the generalization of the geological engineering model. This method proved effective for stability analysis of highly-jointed rock-slope excavations, and is significant for engineering evaluation, as well as for disaster prevention and mitigation of complex rock slopes.