A discrete fracture network based modeling scheme for analyzing the stability of highly fractured rock slope

Abstract

Numerical investigation on stability of the rock slope with densely distributed fractures is still challenging. To overcome the large computational requirements caused by the fracture representation, material heterogeneity and mathematical nonlinearity, an efficient discrete fracture network (DFN) based modeling scheme is developed in this paper. With DFNs stochastically generated according to the statistical distributions of the fractures for resembling the natural fractured rock slope, finite element method (FEM) based strength reduction analysis is conducted for locating the critical slip surface and assessing the factor of safety, where the rock blocks are discretized as solid elements while discrete fractures are practically modeled by frictional contact interface elements. The effectiveness of the proposed approach is validated by comparison against analytical and several numerical solutions. A case study is further performed to evaluate the effects of DFN realization number and geometrical configuration on the stability of the fractured rock slope. It shows that 20 DFN realizations are sufficient to obtain a statistically convergent mean of the factor of safety. The predicted critical slip surface displays to be non-circular but linear or broken line morphology along the fracture network. The proposed numerical scheme shows to be useful and promising in investigating the deformation response and sliding failure mode in highly fractured rock slope. Massive fractures disorder the displacement distribution of the slope and influence the overall factor of safety, and the estimated factor of safety decreases with the increase ofslope height and angle, indicating the fracture distribution and slope geometric features as the prominent influential factors.