Aguilar, J, Mautino, L & Lazon, J 2025, 'Controlled rockfall tests to assess lateral dispersion of trajectories in Antamina Pit', in JJ Potter & J Wesseloo (eds), SSIM 2025: Fourth International Slope Stability in Mining Conference, Australian Centre for Geomechanics, Perth, https://doi.org/10.36487/ACG_repo/2535_08 (https://papers.acg.uwa.edu.au/p/2535_08_Aguilar/) Abstract: Rockfalls are rapid movements that can occur unexpectedly due to the condition of rock slopes and represent a high-risk for mining operations. These rockfalls can also result from planned mining activities on upper slope crests, causing the projection of large quantities of blocks onto lower mining levels or haul roads. This document aims to evaluate the lateral dispersion of rock trajectories during rockfall along various mining slopes through controlled tests within the Antamina pit, highlighting areas of higher or lower risk of falling fragments during such mining operations and providing operationally safe recommendations. Using aerial topographic tools (photogrammetry) and videos recorded during block launch tests, restitution properties of materials were calibrated. Rocscience’s three-dimensional (3D) rockfall simulation software, Rocfall3 (version 1.013), was used to generate 3D models and measure average dispersion angles during block fall to the final accumulation zone. As an additional verification method, images captured by synthetic aperture radar (SAR) around the pit during actual mining operations were analysed to measure lateral dispersion angles and block impact distances. This information supports risk management associated with block release from upper slopes during mining, helping to define risk zones and safe lower areas for ongoing mining activities. Keywords: controlled testing, 3D rockfall simulation, lateral dispersion, calibration, restitution parameters, risk zones