Dissertações em Engenharia de Barragem e Gestão Ambiental (Mestrado) - PEBGA/NDAE/Tucuruí

URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/9396

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Agora exibindo 1 - 3 de 3

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Análise dos efeitos da detonação na estabilidade de talude em mina de ferro no Quadrilátero Ferrífero em Minas Gerais
(Universidade Federal do Pará, 2022-08-03) AZEVEDO, Daniel Prado; MARQUES, Eduardo Antonio Gomes; http://lattes.cnpq.br/6725413897416818; ALENCAR JÚNIOR, Júlio Augusto de; http://lattes.cnpq.br/3663658632717465
The vibrations induced by blasting in mining are finite waves that can disrupt geotechnical structures. For the present research, seismographs were installed in various positions along a slope with approximately two hundred meters of difference in height from the bottom of the pit to the top, in order to analyze the speed and acceleration of the particles at the moment of the wave transmission and their consequences to the stability of rocky mass. It is known that the course of these vibratory oscillations causes the particles to move and then return to the equilibrium state. Therefore, it is important to study which waves were generated in the detonation and their behavior in the lithology covered. A slope in the selected mine, Vale S.A. property, was analyzed, which is composed mostly of phyllite and quartzite, sometimes continuous, sometimes discontinuous, as there is a fractured zone of N / S orientation that extends from the top of the slope to its base. In this context, there are at least 3 fracture directions that act as an escape zone for groundwater, constituting a geotechnical problem of material disaggregation, resulting in great erosion. The vibrations induced by the detonations of explosives in the mine can increase the erosion condition when they propagate through the fractured area. The highest seismographic reading obtained among the seismographs was used in this study and the evaluation of the reduction in the safety factor of selected sections was carried out. Later, the maximum value for vibration in which the slope remains stable is also calculated, on Slide2 software. The evaluation of the results on the slope Allowed the interpretation of the effects of vibrations on the slopes reduced between 4.1% and 4.8% the values of the safety factors and shows that the lower the slope safety factor, the greater this interference from the vibration in the stability of the structure. A difference equal to 8% was observed when comparing the section with the highest Safety Factor and the one with the lowest Safety Factor.
Acesso aberto (Open Access)
Critérios operacionais para redução da contribuição de sedimentos gerados em pilhas de estéril
(Universidade Federal do Pará, 2018-11-14) COSTA, Glayce Wivyanne Oliveira; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
Failure to construct and / or operate sterile piles can lead to significant environmental impacts due to the management of sediments from erosion processes, especially in the rainy season, making it necessary to prepare mitigation plans that take into account the behavior morphodynamic characteristics of the land, as well as the rate of sedimentation or the sediment load that can be incorporated into the watercourses during the different constructive stages of the structures, in order to guarantee the integrity of the flora around the enterprise, as well as to optimize the destination of the tailings and sediments within the space defined for the mining activities. In this sense, this study aims to analyze the process of sterile disposal and solids generation in iron ore sterile disposal cells from open pit mines, thus indicating operational criteria that subsidize the reduction of the contribution of sediment generated in batteries for the environment. In order to carry out this work, a Vale sterile stack was installed in the Mineral Province of Carajás, called PDE NW II, for which a documentary research and critical analysis of the main factors involved in the erosive dynamics of the structure was carried out. In this context, rainfall histories, soil cover classification, size and morphology of the contribution basin are included, as well as the quantification of sediment carried by the structure to downstream portions. The methodology used was efficient, mainly because it was able to correlate cause and effect, in the evaluation of the routines of implantation and operation of the piles, in order to make preventive actions intuitive, in order to minimize the contribution of sediment to the environment.
Acesso aberto (Open Access)
Desafios para implantação dos protocolos estabelecidos no Padrão Global da Indústria para a Gestão de Rejeitos (GISTM), estudo de caso: estruturas de disposição de rejeitos no sudeste do Pará
(Universidade Federal do Pará, 2025-04-25) SOUSA, Rodolfo Pereira; SILVA, Adriano Frutuoso da; http://lattes.cnpq.br/3321059172343690; https://orcid.org/0000-0003-1710-8862
The creation of the Global Industry Standard on Tailings Management (GISTM) is a milestone for the world's largest mining companies, created with the aim of guaranteeing zero harm to communities and the environment This research aims to present the challenges of implementing the GISTM (Global Industry Standard on Tailings Management) for tailings disposal structures, located in the southeast of the state of Pará, being a dam, raised downstream, and a pit, which is an old mining area where the mineral reserve was exhausted in 2021. In order to assess the levels of compliance with the Global Standard, the technical collection of the tailings dam and pit was used to enable the application of the Compliance Protocols proposed by GISTM. The work presents the level of maturity in 3 stages, in the years 2023, 2024 and 2025. Although GISTM proposes requirements for an integrated analysis of tailings management, due to the different nature of the tailings disposal facilities, the facilities were evaluated in isolation. Based on the research, the dam was found to be more compliant with the items required by GISTM, with a more robust technical document framework than the pit. It is concluded that this result is correlated with the fact that the dam complies with Brazil's National Dam Safety Policy (PNSB), while the pit, as a tailings disposal structure, has no regulations for this use. In addition, it should be noted that although the pit is considered an unconventional disposal structure, the implementation of GISTM is required, subject to some adaptations in the understanding of what is proposed by the GISTM.

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