Monitoramento de Barragem de Rejeito Através de Métodos Geofísicos: Interferometria Sísmica do Ruído Ambiente e Eletrorresistividade – Barragem B1B4, Araxá (MG)

Mining Tailings Dam Monitoring Using Geophysical Methods: Ambient Noise Seismic Interferometry and Electrical Resistivity – B1B4 Dam, Araxá (MG)

Abstract

Tailings dams for mining and industrial waste require constant monitoring due to their environmental impact and the risk of failure. In Brazil, there are 941 registered dams, 340 of which are located in Minas Gerais. To ensure the integrity of these structures, monitoring is conducted through visual inspections and conventional instrumentation, such as piezometers, which require significant time and planning for data processing. Geophysical methods emerge as complementary alternatives, offering broader coverage and faster data acquisition. Thus, this study aims to evaluate the physical parameters of the B1B4 Dam, located in Araxá, using Ambient Noise Seismic Interferometry, which monitors variations in the S-wave velocity (Vs), enabling the assessment of changes in the structure's stiffness modulus, and electrical resistivity, which identifies moisture zones categorized into low (<90 ohm.m), intermediate, and high resistivity zones (>400 ohm.m). Seismic interferometry data showed greater variations in Vs during periods of high rainfall, suggesting changes in the physical properties of the dam body. Electrical resistivity data indicated the presence of conductive and resistive areas, providing information to identify “Higher Moisture Zones”. The integration of these methods proved effective in monitoring changes in the dam's physical properties, complementing traditional techniques.