Assessment of filtration stability of tailings dam on the basis of hydrogeomechanical 3D modeling

On the example of the tailings dump of one of the mining enterprises of the Kola Peninsula, model studies of the filtration stability of its enclosing dam were carried out. For this, a hydrogeomechanical 3D model was created, reflecting geometric dimensions, geomechanical and hydraulic conditions of the dam. A distinctive feature of the developed model was the possibility of integrating engineering-geological, geomechanical and hydrogeological conditions, which made it possible, along with geomechanical calculations (soil displacements), to perform hydraulic (head gradient and drainage water outlet). Using Plaxis 3D, calculations were made based on scenarios of the degree of filling of the tailings storage with water due to increased technological discharges of industrial water or flood flooding. Based on the results of modeling, estimates were made of the geomechanical (soil displacement) and hydraulic (head gradients) conditions of the dam, as well as patterns of formation of the depressive surface of the water draining through the body of the dam and its exit to the daytime surface were revealed. Dependencies of head gradient and stability coefficient on the water level in the tailings storage are determined according to the accepted scenarios. A comparative analysis of the calculated values of head gradient and stability coefficient was carried out with criteria for a hydraulictechnical structure of class 1. The filtration stability of the tailings dam was evaluated for the considered conditions depending on the change in the water level in the tailings storage. The applied methodological approach provides a scientific and technical basis for assessing the filtration stability of the enclosing dam of a particular mining tailings dump, taking into account its geomechanical and hydraulic conditions.

Kalashnik N. A. Assessment of filtration stability of tailings dam on the basis of hydrogeomechanical 3D modeling. MIAB. Mining Inf. Anal. Bull. 2022;(12-1):5-15. [In Russ]. DOI: 10.25018/0236_1493_2022_121_0_5.

N.A. Kalashnik, Researcher, Mining Institute, Kola Scientific Centre of Russian Academy of Sciences, 184209, Apatity, Russia, e-mail: n.kalashnik@ksc.ru, ORCID ID: 0000-0001-7651-6562.

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