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Article dans une revue
High-Frequency Hydroacoustic Monitoring in an Underground Iron Mine
Abstract : The monitoring of the stability of old mines constitutes an important research objective for our institution, BRGM. The study reported here shows the contribution of high-frequency (>30 kHz) acoustic emissions to the detection of the damage within a rock mass, during an experiment within a pilot site of an old flooded iron mine. The experiment consisted of recording all the hydroacoustic events in a broad frequency band (between 30 Hz and 180 kHz), during 18 months. The monitoring network has been calibrated by a triggered block fall that made it possible to highlight a relationship between the occurrence of high-frequency/low-frequency hydroacoustic emissions and rock falls. The events recorded have been associated with the micro-failure of the rock mass near the roof, prior to the detachment of the blocks. This monitoring showed important high-frequency hydroacoustic activity, which may be associated with mechanical instabilities generated by the evolution of water pressure during the experiment. In conclusion, the high-frequency hydroacoustic activity appears to be a good indicator of instability and, therefore, this new technique constitutes a promising tool for monitoring abandoned underground cavities.
https://hal-brgm.archives-ouvertes.fr/hal-03647368
Contributeur : Frédérique Couffignal Connectez-vous pour contacter le contributeur
Soumis le : mercredi 20 avril 2022 - 14:38:43
Dernière modification le : jeudi 21 avril 2022 - 03:36:47
Contributeur : Frédérique Couffignal Connectez-vous pour contacter le contributeur
Soumis le : mercredi 20 avril 2022 - 14:38:43
Dernière modification le : jeudi 21 avril 2022 - 03:36:47