Probabilistic Rockfall Analysis in 3D in The Peña Colorada Open Pit (Colima, Mexico)

Rockfall events are one of the most difficult geotechnical conditions to predict and control in a mining operation. 

This study is focused on the Peña Colorada open pit (Colima, Mexico), where a series of rockfalls occurred on the main slope during the period of Hurricane Lidia (October 2023). The proposed methodology is based on a probabilistic analysis and field inspections to identify potential rockfall sectors. 

The topographic survey was obtained with photogrammetry using a drone for identifying potential sectors. Then, the properties such as restitution coefficients and the friction angle has been calibrated based on field tests of the different terrains observed on the main slope (rock and spill). 

The results obtained in the Rfall 3D simulations are interpreted, compared, and calibrated with real-scale field tests performed on the main slope. Finally, solutions to mitigate rockfall risk are proposed, such as temporary or permanent closure of haul roads or implementation of barriers.