Avaliação de segurança de barragem: análise geotécnica e classificação – estudo de caso de barragem de mineração

Abstract

Dams are engineering works whose function is to dam up a region to contain or accumulate liquid substances or a mixture of solid and liquid loads. In the mining area, these structures receive tailings and/or sediments from mining activities. The collapse of a dam results in social, environmental, and economic impacts, in most cases irreversible, as occurred in the Fundão and Córrego do Feijão Dams, in Minas Gerais. For this reason, the evaluation of dam safety is indispensable, as it will enable timely preventive and corrective interventions, for the safety of the structure, the environment, and third parties in its area of influence. This work presents a case study of a mining dam, whose purpose is the evaluation of geotechnical safety and classification of the structure according to current legislation, based on the current conditions of the dam. To reach these objectives, information about the dam was acquired and the instrumentation, internal drainage system and downstream slope stability were analyzed. Finally, it was concluded that, during the period analyzed, the structure presented acceptable geotechnical conditions, in addition to satisfactory safety factors according to NBR 13.028/2017. Regarding classification, according to ANM Resolution nº 95/2022, the containment dike is classified in relation to the Risk Category (CRI) is Low and in relation to the Associated Potential Damage (PDA) is Medium.