Stability assessment of rock slopes based on Discrete Fracture Networks (DFNs)

Abstract

The stability of rock slopes is primarily influenced by discontinuities. Since it is difficult to measure 3D systems of natural discontinuities (fracture networks), stochastic approaches have been developed using statistics from limited samples. A widely used method developed in the 1980s is a stochastically generated Discrete Fracture Network (DFN). A general stochastic DFN approach assumes that fractures are planar discs and treats the other geometrical properties (e.g. position, frequency, size, orientation) as independent variables obeying certain probability distributions derived from field measurements of outcrops. A case study demonstrates how DFNs can be used: on the one hand together with numerical calculation approaches such as the Discrete Element Method (DEM) and on the other hand with the Limit Equilibrium Method (LEM). Furthermore, it is discussed whether and how a Eurocode-compliant assessment of the stability of rock slopes can be carried out in these ways.