Discrete fracture network modelling for hard rock slopes

Authors: Weir, FM; Fowler, MJ Download Paper

DOI https://doi.org/10.36487/ACG_rep/1604_06_Weir

Cite As:
Weir, FM & Fowler, MJ 2016, 'Discrete fracture network modelling for hard rock slopes ', in PM Dight (ed.), APSSIM 2016: Proceedings of the First Asia Pacific Slope Stability in Mining Conference, Australian Centre for Geomechanics, Perth, pp. 157-168, https://doi.org/10.36487/ACG_rep/1604_06_Weir



Abstract:
The design of excavations in rock must, implicitly or explicitly, consider the influence of small and large scale geological structures. For most hard rock sites, the complexity of a fractured rock mass is best captured using a three-dimensional fracture system model based on field data. A discrete fracture network (DFN) approach involves stochastic modelling of the smaller scale, non-deterministic structures. For slope stability projects DFN modelling provides a valuable geotechnical tool for visualisation of a rock mass, identification of likely failure mechanisms and a method for considering uncertainty both in terms of natural stochastic variability and sampling. This paper presents a suite of DFN modelling undertaken for the design of a large open pit in Australia. The model inputs and development are briefly presented, along with the various applications of the DFN modelling. A key advantage of the DFN approach for design studies is its probabilistic application to analyses and results. Multiple realisations of the same model were generated for four structural domains, with the stability analysis carried out on each iteration. The proportion of unstable slope for a range of conditions is compared with results from traditional kinematic and statistical analyses.

Keywords: geological structures, probabalistic, slope stability

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