BCGS Technical Talk – February , 2021
Please note that this talk will be held at 12:00 PM PST.
Speaker: Andrea Certo and Greta Tresoldi, LSI LASTEM S.r.i., Milan Italy
Title: A Remote Resistivity Sensing System to Monitor Tailings Dams Structural Integrity
Date/Time: Thursday February 25, 2021 @ 12:00pm – 1:00pm PST
Location: Online webinar. The webinar link will be sent out via our mailing list in advance of the talk.
Andrea Certo, Instrumentation Engineer. Andrea will describe the development and implementation of the GRETA resistivity monitoring System
Andrea is CEO and owner of LSI-LASTEM S.r.i. which provides environmental monitoring systems for hydrological, meteorological, industrial and geophysical applications.
Dr. Greta Tresoldi, Environmental Engineer / Geophysicist. Greta will describe the geophysical implementation of resistivity monitoring and software integration for noise reduction, elimination of spurious effects, automatic inversion, translation of results to percent water saturation, integration with piezometer and other dam monitoring systems and integration with minesite monitoring networks.
Greta is a Ph.D. Environmental Engineer and Geophysicist. After three years as a university Researcher at Politecnico di Milano in the field of applied geophysics for hydrogeological risk reduction, she is now Product Manager at LSI Lastem. An earlier contributor to the G.Re.T.A. system, as she has been working on the project from its very beginning.
G.Re.T.A.” A Remote Resistivity Sensing System to Monitor Tailings Dams Structural Integrity
By Andrea Certo and Greta Tresoldi, LSI LASTEM S.r.i., Milan Italy
The increasing number of tailings dams’ failures in the recent decades highly demand to set up reliable systems to monitor the stability of these structures. Appropriate design, efficient operation and continuous monitoring are key solutions to guarantee the stability of earthen embankments including tailings dams.
Electrical resistivity tomography (ERT) is widely used in the mining industry for mineral exploration, groundwater studies, characterizing mine wastes and monitoring acid mine drainage. We present the capability of an Italian geo-electrical monitoring system (developed by LSI Lastem with the scientific support of Politecnico di Milano) for permanent monitoring of tailings dams.
G.Re.T.A. (Geo Resistivimeter for Time-lapse Analysis) is an autonomous ERT system including a remotely controlled resistivity-meter with two cables connected to 48 stainless steel electrodes. The protected cables can be buried in shallow trenches along the embankments. The system can be powered by solar panels or power grid. Datasets of resistivity sections and acquisition parameters are available on a cloud platform. Site-specific algorithms for time-lapse data analysis and visualization of resistivity differences for any desired measurement period are available online to monitor the subsoil in real-time. An automatic control algorithm can detect if changes have approached pre-set thresholds while sending alarms about anomalous changes to the customer.
The advancement of G.Re.T.A. is that it can be implemented as a long-term monitoring system to underline the internal heterogeneities or the tailings dams based on changes in resistivity values. The efficiency of the system has been proved in pilot sites for monitoring the internal conditions of river levees and through laboratory tests for shallow landslides. One G.Re.T.A. system was also installed in 2020 in a tailings dam in Chile to monitor underseepage. The system is capable of being used to monitor the inner properties of mine wastes, heap leaching facilities and tailings dams.