Slope movements in open pit mines

Impact of uncontrolled instabilities and the importance of an effective slope monitoring program

Dr Paolo Farina

Reliable slopes are essential to the design of an open pit mine and for its operations. However, instabilities do occur and as such, remediation requires an understanding of the dynamics at play in order to minimize risk potential for continuing mine development.

To achieve safety and maximize economic performance objectives requires an effective slope monitoring system. Nowadays most large open pit mines, as part of their slope performance monitoring program, have sophisticated and complex systems in place for near real time monitoring; as well as integrating different technologies including robotic total stations, GPS, piezometers, wire extensometers, radar, InSAR, etc. All of these sensors automatically acquire every day Terabytes of data transferred and stored, often in separate databases at the mine offices. Experience indicates that despite the availability of monitoring data and dedicated site staff in charge of the management of risk, negative and surprise geotechnical events associated with slope instabilities continue to occur in surface operations. Difficulties experienced at the operations level in the aggregation, interpretation and timely reporting of monitoring data are common and need to be corrected. Due to time limitations and sometimes from a lack of training, the slope engineer is not always able to fully exploit the informative content of the available data. This may result in the inability to correctly determine the most likely risk scenarios, in terms of volume of the material involved, potential run out distance and temporal evolution of the instability. A number of case histories of slopes where instabilities did occur will be presented in the seminar focusing on how integrated monitoring data were used to manage geotechnical risk associated with the slope movements.

About the speaker

Dr Paolo FarinaCo-founder and President of Geoapp srl

Paolo has a PhD in Earth Sciences from the University of Firenze, with a thesis on the use of satellite and ground-based radar interferometry for slope monitoring, and a MSc in Engineering Geology cum laude. From 2015 Co-founder and President of Geoapp srl, academic spin off of the University of Florence. As President of Geoapp Paolo’s goal is to introduce new practices into the mining industry focusing on slope monitoring, geomechanics and geotechncial risk assessment. He is working as consultant at international level with mining clients in Indonesia, PNG, Turkey, Norway, Botswana, Brazil, etc. From 2015 to 2017 Paolo was appointed as Research Associate at the University of Florence working on rock mechanics and deformation monitoring research projects in the mining and infrastructure industries. From 2007 to 2015 he worked as manager of the Mining Business Unit in the Georadar Division of IDS SpA, where he successfully introduced a new slope stability radar based on SAR technology into the mining industry. Before joining IDS, from 2003 to 2007, he worked as assistant professor at the University of Firenze, within the engineering geology group at the Earth Sciences Department. More than 65 scientific publications on international and national peer reviewed journals and experience as reviewer for international journals (International Journal of Rock Mechanics & Mining Sciences, Engineering Geology, Geomorphology, Int. Journal of Remote Sensing, Int. Journal of Landslides, Trans. of Geoscience and Remote Sensing).

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