Lambert, C 2008, 'Variability and Uncertainty on Rock Mass Strength Via a Synthetic Rock Mass Approach', in Y Potvin, J Carter, A Dyskin & R Jeffrey (eds), SHIRMS 2008: Proceedings of the First Southern Hemisphere International Rock Mechanics Symposium, Australian Centre for Geomechanics, Perth, pp. 355-366, https://doi.org/10.36487/ACG_repo/808_93 (https://papers.acg.uwa.edu.au/p/808_93_Lambert/) Abstract: By combining the benefits of the particle flow code PFC3D to represent the rock and the benefits of a geostatistical tool to generate a full three-dimensional (3D) discrete fracture network (DFN) of the domain, it is possible to create, using typical field data, a synthetic rock mass (SRM) that is representative of the geotechnical domain. The SRM is then submitted to a series of numerical tests (triaxial tests, UCS tests) using PFC3D to assess the constitutive behaviour of the rock mass. The model exhibits a wide range of typical behaviours of a real rock mass, such as anisotropy and a scale effect. To better understand the influence of the structural pattern of a rock mass on its strength, an extensive series of simulations has been carried out varying some of the key parameters of the DFN (joint persistence, joint spatial density or joint friction angle). The results of the simulations are analysed and discussed. An attempt to characterise the rock mass strength variability is proposed.