I Congreso de Postgrado fcfm: ingeniería, ciencias e innovación

67 Santiago, 10 al 12 de agosto, 2022 C I E NC I A S D E L A T I E R R A 03 METODOLOGÍA PARA LA IDENTIFICACIÓN DEL CONTENIDO DE HUMEDAD EN EL MURO DE TRANQUES DE RELAVES BASADO EN LA TÉCNICA DE TOMOGRAFÍA ELÉCTRICA Leopoldo Córdova 1,2 , Diana Comte², Daniel Diaz² ¹Geosinergia Ingenieria y Medioambiente, Santiago, Chile. ²AMTC-FCFM, Universidad de Chile, Santiago, Chile. *Email: lcordovaie@gmail.com ABSTRACT The most frequent cause of failure on tailings dam is related to the action of water seepage and leakage through the tailings dam wall, resulting in instability and dam failure [1]. In tailings failures reports around the world, one of the recommendations is to monitor periodically the conditions of non-saturation that were established at the dam design [2]. One of the methodologies of monitoring that has been increasingly used for the detection of internal erosion and infiltration, is through the observation of electrical resistivity, especially using the technique of electrical resis- tivity tomography (ERT) [3][4][5]. Even if this geophysical technique allows a ground characterization of resis- tivity, the step to convert this to humidity percentage is not simple, with certain difficulties also in the conversion to depth, and the definition or resolution that can achieve because of the interference of the tailings dam content, and the relationship between the resistivity and real humidity content that we want to detect. This investigation presents the development of a methodology to obtain the real humidity percentage with ERT technique and moisture sensors at different depths in a well, instead of the application of Archies law through lab tests. The acquisition of ERT is currently an ongoing project during the well instrumentation campaign of a tailings dam up north of Chile. (A results preview can be seen in the following figure). Figure. Left image: ERT profile acquired at tailings dam. Right image: Moisture sensor data acquired from a well in the same tailings dam. ACKNOWLEDGEMENTS The tests related to this investigation have been carried on with Geosinergia Company in Chile central valley, they contribute with their operative collaboration and with the soil moisture sensors as well. REFERENCES [1] Tsf failures from 1915, csp2. Center for science in public participation.Mgz. (2020) [2] Newcrest Release, Report on NTSF Embankment Failure, Cadia Valley Operations. (2019) [3] Sjödahl, P., Dahlin, T. Detection of internal erosion and seepage evaluation, 97(10) , 54-56. (2007) [4] Arjwech, R., &Everett, M. E. Application of 2D electrical resistivity tomography, 37 , n.6. (2015) [5] Camarero, P. L., Moreira, C. A. Analysis of the physical integrity, 176(12) , pp.5363-5375. (2019)