GarcĂ­a, I & Pastine, S 2020, 'Analysis of the effect of back-break on rockfall trajectories', in PM Dight (ed.), Slope Stability 2020: Proceedings of the 2020 International Symposium on Slope Stability in Open Pit Mining and Civil Engineering, Australian Centre for Geomechanics, Perth, pp. 1173-1182, https://doi.org/10.36487/ACG_repo/2025_78 (https://papers.acg.uwa.edu.au/p/2025_78_Garcia/) Abstract: An effective bench design must arrest and mitigate the danger of rockfalls and contain ravelling from the benches above. Rockfall analyses based on 3D rigid body dynamics can be useful to assess the adequacy of a bench design in terms of risk of impact, as long as the slope geometry and the coefficients of restitution are estimated with enough accuracy. This paper presents a study of the effect of back-break on the rockfall hazard at the bench stack toe. Back-break distributions are taken from measurements carried out at a mine in South America and then applied to the design bench geometry, whereby crests are displaced into the slope. This provides a more realistic slope surface for rockfall calculations. This work builds on Pastine et al. (2018) by incorporating the relationship between the mass of the falling rocks and the coefficient of restitution, as indicated in (Basson et al. 2013). Keywords: catch bench, rockfall analyses, back-break, coefficient of restitution