Step Path Rock Bridge Percentage for Analysis of Slope Stability

Step path (“En-echelon”) slope failures form as a combination of sliding on fracture surfaces and tensile failure of rock bridges between those fractures. This paper presents a new method for estimating rock bridges using a searching algorithm that identifies potential failure pathways through Discrete Fracture Network (DFN) models which more realistically represent the spatial pattern of fracturing, with realistic fracture sizes, intensity variation, and orientation. The approach differentiates between rock bridges failing under shear and those failing under tension. Without the need for complex numerical simulations, the approach can analyse multiple slope sections to provide a probabilistic assessment of the rock bridge percentage and slope stability. The resulting step path “rock bridge percentage” can also be applied to conventional continuum approach as an anisotropic rock mass strength