Estudo do comportamento de barreiras poliméricas em sistemas de disposição de rejeito de minério de ouro

• Ano de defesa: 2013
• Autor(a) principal: Soraya Salatiel Sampaio
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Dano mecânico; Resistência ao cisalhamento de interface; Geomembrana; Durabilidade; Resistência ao cisalhamento; Mecânica do solo
• Link de acesso: http://hdl.handle.net/1843/BUBD-9N7HJS

Due to the increasing use of polymeric geosynthetics barriers (GBR-P), also known as geomembranes, in waterproofing systems of tailings dams, it is important to evaluate their properties when applied in a similar field condition, because of the low shear strength of the interfaces, which can become a potential surface of rupture. The Jacobinas tailings dam, owned by the enterprise Yamana Gold, was built in Brazil in 2008 to store the tailing generated over the next 20 years of mine operation. In order to prevent the contamination of soil and groundwater, the foundation, the reservoir and the upstream slope of the dam were coated with a 1.5 mm thick of a high density polyethylene (HDPE) geomembrane. The dam will be built in seven stages, with the downstream raised method and have a maximum depth of 115.0 meters. The aim of this study is to verify the geotechnical behavior of the Jacobinas dam, by testing shear strength of geomembrane-tailing and geotextile-tailing interface and investigate the geomembrane and geotextile damage in contact with granular material under normal stress. The behavior of geosynthetiques used in the dam it was also evaluated by testing simple tensile strengh of three types of samples: exhumed, virgins and subjected to the durability test. Shear tests were conducted under flooded condition, with normal stresses of 125, 500 and 700 kPa and the degree of compaction 95% and 98%. The mechanical damage tests were performed under normal stresses of 100, 250, 500 and 1000 kPa and the the height of water applied in the trials was 2.5 m. The study results showed that the interface friction angles were higher than the values adopted in design of the dam, which were based on values obtained in the technical literature, certifying the stability of the dam. Tests of mechanical damage, during and after the application of normal stress, showed no leaks and the visual inspections performed after testing has shown that there is no apparent damages, thus proving the effectiveness of the project implanted.