Assessment of Geoelectrical and Seismic Methods for Tailing Dams – Catalão GO

Abstract

Mining tailings dams are engineered structures designed for the disposal of waste materials generated during mineral processing. These structures require continuous geotechnical monitoring, including visual inspections and manual or automated instrumentation, to ensure their safety and stability. This paper presents the application and results of geophysical methods used to monitor and investigate a tailings dam. In Brazil, recent dam failures have prompted significant improvements in legislation, technical standards, and geotechnical investigation protocols. Electrical resistivity was employed to map low-resistivity zones, which are associated with higher degrees of saturation within the dam structure. Ambient noise seismic interferometry enabled real-time monitoring of variations in S-wave velocity (Vs), with reductions reaching 11% at the dam crest. This reduction was linked to higher saturation levels near the right abutment, likely intensified by seasonal rainfall. Additionally, the multichannel analysis of surface waves confirmed the decrease in Vs in areas correlated with those of low resistivity, suggesting increased saturation. Ambient Noise Seismic interferometry also detected a partial recovery in Vs over time. The integration of these geophysical techniques allowed for the identification of structural anomalies and supported the implementation of corrective engineering measures, contributing to improved dam safety and risk management.