Programa de Pós-Graduação em Engenharia de Barragem e Gestão Ambiental - PEBGA/NDAE/Tucuruí

URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/9395

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Agora exibindo 1 - 20 de 27

Acesso aberto (Open Access)
Análise da adição de resíduos siderúrgicos em matrizes cimentícias para concreto massa
(Universidade Federal do Pará, 2021-12-17) BONFIM, Francirene Pereira; GOUVEIA, Fernanda Pereira; http://lattes.cnpq.br/1772072130947378
During the steel production process, industrial waste is generated, including granulated blast furnace slag and balloon powder, generated in the pig iron production stage; and electric arc furnace dust, obtained in the production stage of the steelworks. In the northern region, the highlight in steel production is SINOBRAS - Siderúrgica Norte Brasil SA, located in the municipality of Marabá-PA, which also experiences the problem of waste disposal, and therefore has been supporting partnerships with educational institutions in the region for expansion of destination alternatives. Thus, this research aims to evaluate the influence of waste from the SINOBRAS industry, granulated blast furnace slag (GBFS), balloon powder (BP) and electric arc furnace dust (EAFD) in cementitious matrices, predicting applications in mass concrete for dams . The research methodology was carried out in two stages, the first being directed towards the study of waste, analyzing its physicochemical and mineralogical characteristics, the pozzolanicity potential according to ABNT NBR 12653:2015, and classification according to the type of solid waste according to ABNT NBR 10004:2004. The second stage of the methodology comprised the analysis of cement matrices composed of the residues, combined with GBFS (GBFS70+BP30; GBFS50+EAFD50), in order to increase the potential performance of the properties verified for mass concrete, with compressive strength tests being carried out, setting times, heat of hydration and alkali-aggregate reaction. It was concluded in the residue study stage that BP and EAFD did not present pozzolanic properties, indicating that they are not interesting for applications of cementitious materials. As for the classification, the GBFS and the BP were classified as class IIA waste - non-hazardous and non-inert, while the EAFD was classified as class I - hazardous. In the second stage of the study, the EAFD combined with the GBFS showed pozzolanicity and the BP, even after combination, remained non-pozzolanic. Evaluating the combined cementitious matrices, the (GBFS50+EAFD50) obtained satisfactory results in all properties, since it promoted a reduction of heat of hydration by 7% and, consequently, an increase in setting times (about 6 hours), and mitigation of expansion reactions, in aggregates gravel and sand by 49%. and 75% respectively. Therefore, the use of the matrix GBFS50+EAFD50, in the studied content, can be a technically viable alternative for applications in mass concrete for dams, being necessary, however, to advance in the research, aiming to produce the concrete traces composed by the matrix combined (GBFS50+EAFD50).
Acesso aberto (Open Access)
Análise computacional do rompimento hipotético da barragem de Tucuruí-PA com o auxílio do software Mike Flood
(Universidade Federal do Pará, 2017-10-10) SANTOS, Marlon Braga dos; GOUVEIA, Fernanda Pereira; http://lattes.cnpq.br/1772072130947378; SANTOS, Viviane Almeida dos; http://lattes.cnpq.br/1489376127395764
Present work seeks to elaborate flood maps and to perform the flood wave analysis, due to the hypothetical break of the dam of the Tucuruí Hydroelectric Power Plant (Tucuruí HPP), using commercial software MIKE FLOOD. For such purpose, are considered, the overtopping scenario and the total rupture of the Tucuruí HPP concrete dam. Methodology adopted for the research consisted of the collection of technical information regarding the damming, in addition the hydrological study of the areas upstream and downstream of the dam, that are essential for the definition of the input parameters in the computational model to be elaborated. Computational hydrodynamic modeling was carried out in three stages: the first consisted of an one-dimensional analysis in MIKE 11 software; subsequently, with the MIKE 21 software, the triangular calculation mesh was generated for the two-dimensional analysis; and finally, the coupled analysis of the two models previously developed with the MIKE FLOOD software was proceeded. Results indicated areas of flood of up to 84.71 km² for the first one hundred and ten minutes after the rupture gap formation, with a reaction time of approximately eight minutes for the resident population in the urban area of Tucuruí, indicating high potential of loss of human life. It should be noted that the hypothetical floodplain covers residential areas and the commercial center of the city, as well as several urban facilities and public agencies, in addition of one of the most important access roads to the city, BR 422, which restricts the definition of evacuation of the affected population. Thus, it is concluded that the consequences of the rupture of the Tucuruí HPP for the analyzed scenario justify the elaboration of an Emergency Action Plan that guarantees the population security the downstream and that minimizes the economic and environmental impacts resulting from such event.
Acesso aberto (Open Access)
Análise das ações de resposta ao cenário de rompimento de barragem de Tucuruí no contexto do PAE e PLANCON
(Universidade Federal do Pará, 2024-09-10) SILVA, Francisco Júnior Nascimento da; GOUVEIA, Fernanda Pereira; http://lattes.cnpq.br/1772072130947378
As a result of the latest accidents involving the dam collapse scenario in Brazil and the strong demand from society and supervisory bodies demanding more safety in dam projects, Eletronorte, responsible for HPP Tucuruí, in 2017 prepared the Safety Plan, and in 2023, together with the municipalities located in the ZAS (Self-rescue Zone), it consolidated the integration of Emergency and Contingency Plans. In this sense, this work aimed to analyze the response actions to the Tucuruí dam collapse scenario in the context of municipalities located in ZAS. The methodological steps used to achieve the results were as follows: Characterize the Tucuruí HPP and the municipalities located in the ZAS (Tucuruí and Breu Branco); Description of the history of preparation and integration, PAE-UHE Tucuruí and PLANCONS of the ZAS municipalities; Evaluate the structuring of COMDECs in the ZAS municipalities, based on the criteria of the COMDECs Diagnostic Report in Brazil and Evaluate the operational logistics of the SCI (Incident Command System) defined in the PLANCONs of Tucuruí and Breu Branco. The results revealed that COMDECs are deficient in terms of training, and in Tucuruí, agents need additional training that meets the thematic axes offered by the National Civil Protection and Defense System – SINPDEC. At COMDEC Breu Branco, a lack of training for all members was identified, with courses being carried out only by the coordination. The financial resources verified to support COMDECs' actions are only allocated in cases of occurrences and there is no preventive financial planning in both municipalities. In terms of infrastructure, COMDEC in Breu Branco is not capable of operating in this emergency scenario, as it has limitations in terms of response support from the 8th GBM. Finally, this study presented, for the first time, the weaknesses observed in the context of the collapse of the Tucuruí dam, in terms of the operationalization of the PAE-PLANCONs in the ZAS municipalities, demonstrating that the COMDECS need better structuring and that the Plans must undergo planning adjustments, aiming for better effectiveness in response actions, which can reduce the vulnerability of the population in the post-disaster period.
Acesso aberto (Open Access)
Análise do impacto ambiental na área de influência das barragens de rejeito no município de Poconé-MT
(Universidade Federal do Pará, 2023-09-29) FERREIRA, Lorrana Dias; SILVA, Adriano Frutuoso da; http://lattes.cnpq.br/3321059172343690; https://orcid.org/0000-0003-1710-8862
Due to tragic accidents related to the failure of tailings dams in Minas Gerais, the disposal of tailings in dams has become an increasingly urgent topic of discussion, especially in relation to the risks associated with this approach. Consequently, mining companies have sought to implement alternative methods for managing tailings resulting from their operations. However, in this direction, the work analyzes the level of the environmental impact in the area of influence of tailings dams in the municipality of Poconé – MT, identifying the major damages that can be caused by a tailings dam rupture. To this end, maps of environmental impacts on the selected dams were created, using the software QGIS, also known as Quantum GIS. The Kernel method was also used, which is an analytical approach that is frequently applied in the assessment of risks and environmental sensitivity in relation to mining tailings dams. The results of the research revealed that throughout the work it was possible to observe that the mining tailings dams existing in the municipal limit of Poconé/MT are defined as structures that promote a “very high” environmental impact, mainly in the urban area than if it occurs the rupture could affect legal preservation areas and the city's drainage system, thus impacting the life of the community in general. With the data obtained, it was possible to analyze the environmental impact of tailings dams on local communities, including the possible relocation of families, access to drinking water and the health of people living nearby. Therefore, the analysis of the environmental impact in the area of influence of tailings dams in Poconé, Mato Grosso, is a crucial part of the responsible management process of mining activities, as it can help develop strategies to mitigate these impacts and ensure the protection of the environment.
Acesso aberto (Open Access)
Análise do monitoramento de segurança de barragens de terra do aproveitamento hidrelétrico de Belo Monte: estudo de caso de diques do complexo no cenário do enchimento e operação
(Universidade Federal do Pará, 2019-12-12) MODESTO, Renan Ribeiro; ALENCAR JUNIOR, Julio Augusto de; http://lattes.cnpq.br/3663658632717465; LIMA NETO, Aarão Ferreira; http://lattes.cnpq.br/0287664572311345; https://orcid.org/0000-0002-5911-1368
In Brazil, an execution of earth dams or earth dams are quite common methods and used mainly to meet the demands of mining, irrigation or water storage for the production of hydroelectric energy. It is the importance or the monitoring and safety analysis of these rules to reduce environmental risks, safety factors, technological factors and observe the behavior and performance when planned. This dissertation seeks to understand dam safety monitoring procedures using items 01-A, 01-B and 01-C of the Belo Monte HPP intermediate reservoir by studying the different processes to ensure the safety of organizations. The methodological tracking adopted was carried out through the collection of technical information related to the studied structures, analysis of construction projects and verification of the methodologies adopted to contemplate the filling of reservoirs, reading of all or checklists that are field inspections, in addition to the data of the graphs, results of the auscultation instruments located in the body of the buses in the period of execution and operation that comprised the years 2015 to 2018. The type of research refers to a case study of documentary nature, since they are analyzed safety monitoring data in addition to the behavior of structures. The results reveal that, when compared to the safety procedures adopted at the international level, there is a shortage of the Brazilian safety inspection bodies, it refers to a more specific and clear methodology regarding the process of the first test of a reservoir, and in general lines , non-involved monitoring methods if associated, non-compliance in non-mandatory visual inspections or an instrumental reading outside the reference adopted as safety. However, when different non-conformities and / or anomalies present themselves both in visual inspection and in instrument monitoring, this action requires corrective action in the short term, as it is considered an unfavorable scenario in the security of the structure and associated with the strengthened correlation. to display a downstream of the structures.
Acesso aberto (Open Access)
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)
Análise numérica da estabilidade de taludes utilizando o método de Galerkin livre de elementos
(Universidade Federal do Pará, 2017-05-03) SILVA, Davi Barbosa Costa da; TEIXEIRA, Marcelo Rassy; http://lattes.cnpq.br/8912916360456192
The safety of dams is associated to the stability of the structures that compose them. In a earthfill dam, there are mentioned the slopes, which are surfaces that form an angle with the horizontal one. Its study using numerical methods, like the finite element method (FEM), makes possible the estimate of displacements, stresses and strains. It is aimed in this study to contribute in the efficiency of the numerical analysis devoted to the slopes. Through the development of a resource turned specifically to dams, the objective in the present work is to present an algorithm able to check the stability of slopes in the period of its construction using a numerical method without mesh. For the proposed analyses, there was used the element free Galerkin method (EFGM), applying it in the strength reduction method (SRM). After the idealization of a model and solution using the limit equilibrium method and the strength reduction method with the help of the FEM, both in commercial software (GeoStudio), there were obtained and were compared the results of a model in which there is applied the strength reduction method with the use of the EFGM. The analysis by the strength reduction method was divided in determination of the in situ stresses of the foundation, construction of the landfill and strength reduction of the soil. Numerically, in the stage of getting the in situ stresses, the EFGM presented better result when compared to FEM, taking as a reference the classic mathematical model of the soil mechanics for subhorizontal surfaces. In the stages of construction of the landfill and of strength reduction, the relative approximation error the EFGM regarding the FEM was nearly always superior to 5%. However, it noticed if that in the main answers, i.e. in the determination of the slip surface and of the strength reduction factor, the results were similar, as in the strength reduction method, with the EFGM regarding the FEM, as that regarding the limit equilibrium method. In the comparison with the FEM, there were obtained more conservative strength reduction factors. In spite of being an information not available openly, it concluded if that the elastoplastic constitutive model used in the commercial software is not the linear elastic perfectly plastic model, which was hypothesis adopted for the EFGM. Besides the differences due to the behavior idealized for the material, the application of meshfree method also requires more studies related to the definition of the representation of the domain. The main advantage of the adoption of the proposed method is the possibility to test more parameters in less time, which makes it useful in preliminary construction studies. For that, it must be observed that, in spite of the limitations in displacement estimation, which are useful to associate numerical results to the observations in field, the conditions in which there is slip at slope can be appreciated in satisfactory, conformable way when it was shown in comparisons with the most used methods.
Acesso aberto (Open Access)
Aplicação da ferramenta de risco FMEA para análises dos modos de falha de uma barragem de terra: estudo de caso Projeto Formoso do Araguaia-TO
(Universidade Federal do Pará, 2023-05-15) SANTOS, Andreia Arruda; GOUVEIA, Fernanda Pereira; http://lattes.cnpq.br/1772072130947378
The Formoso River Project, located in the state of Tocantins, is the largest irrigation project in Latin America and its structures, made up of three dams, have worried the supervisory body due to the compromised state of conservation of these structures, with evidence of pathologies and anomalies at various points. The state government, which is the developer of the dams, in 2012 even contracted revitalization projects for the enterprise, but to date the works have not been carried out, which makes the safety of the dams more vulnerable. The general objective of the research is to analyze the risk situation of the Calumbi II dam, which makes up the Rio Formoso irrigation project, through the application of the FMEA (Failure Mode and Effects Analysis) risk tool, identifying the most likely failure modes and with greater potential. Other objectives would be: the description of the interventions recommended by the consultancy hired by the entrepreneur and the critical analysis of the lack of dam safety management. The research methodology was based on four stages: a) characterization of the Rio Formoso Project and the case study dam; b) survey of anomalies and pathologies found in the dam; c) application of the FMEA risk tool and d) critical analysis of the dam's safety management case study. The results indicated that the Calumbi II dam presents several pathologies and anomalies (presence of large trees and shrub vegetation on the crest, retraction cracks, erosion and water surges on the slopes), and that despite the dam operating at minimum levels, failures may occur. The FMEA tool demonstrated that the highest priority failure mode would be upstream slope instability (NPR=336), secondly, failure due to piping (NPR=320) and thirdly, but more remote, failure due to dam overtopping ( NPR=144). From the aspect of the analysis of the safety management of the Calumbi II Dam, the vulnerability of the enterprise was concluded, since the dam does not have a PSB or PAE, it does not have installed instrumentation, there is no professional responsible for safety, it does not have studies of risk assessments, does not receive regular periodic inspections by the supervisory body.
Acesso aberto (Open Access)
Avaliação da segurança da barragem Labourrie/AP à luz de diferentes metodologias
(Universidade Federal do Pará, 2020-03-05) RAMBO, Luis Henrique; SILVA, Adriano Frutuoso da; http://lattes.cnpq.br/3321059172343690
In recent years, dams in Brazil have been constantly related to the occurrence of numerous engineering problems, whether in design, construction methods, control, monitoring, instrumentation, etc., these situations were created as a result of some accidents that occurred, such as Mariana's cases and Brumadinho / MG. The inadequate design and construction of these structures represents a great risk to society, the environment and the economy. Thus, in this work, we chose, as a case study, to analyze the safety of the Laborrie tailings dam, located in the Lourenço district, in the state of Amapá, based on risk analysis and associated potential damage. The methodologies used were: SABESP, COGERH (modified), USACE, CNRH Res. 143/2012 and ANM Ordinance 70.389 / 2017. The study identified the similarity in the methods, oscillating in the weights used for calculations, as well as identified the method that does not use any relevant item in the analysis of tailings dams. Therefore, it is concluded that for the Laborrie Dam case study, the use for risk assessment of tailings dams using the ANM methodology and resolution 143, are the most indicated, which does not invalidate the use of the other methodologies, however, each particularity of the proposed method must be analyzed, in order to fill in the information that really has relevance and direct impact in the search for a closer approximation of the result.
Acesso aberto (Open Access)
Avaliação de alternativas para projetos de descaracterização de uma barragem de rejeito de mineração utilizando análise comparativa multicritério
(Universidade Federal do Pará, 2024-10-10) OLIVEIRA, Pedro Lucas Louzada de; SILVA, Adriano Frutuoso da; http://lattes.cnpq.br/3321059172343690; https://orcid.org/0000-0003-1710-8862
The decharacterization of tailings has become an extremely relevant and urgent topic in the contemporary global scenario. Given the recent disasters and environmental tragedies resulting from the collapse of mining dams in Brazil in 2015 and 2019, the need to implement efficient and safe processes for the deactivation and recovery of these structures has become imperative. The complexity inherent to this type of enterprise demands a careful and comprehensive approach in evaluating the available options. The simple selection of an alternative based on a single criterion, such as financial cost or deadline, for example, can result in adverse consequences and negative impacts from both a technical, economic, environmental and social point of view. Given the above, this dissertation aims to explore the importance of analyzing alternatives considering multiple criteria in the process of choosing the best solution for the mining dam decharacterization project. Through a literature review and presentation of a case study of the decharacterization of a Manganese dam using the assessment of technical, environmental, economic and socioeconomic requirements as a decisive element in choosing the solution to be detailed. The methodology consists of analyzing the proposed alternative scenarios, including the definition and weighting of the multiple variables to be evaluated. The result obtained demonstrates that the adoption of multiple criteria, which encompass not only economic aspects, but also environmental, social, technical and safety aspects, was fundamental to guarantee a well-informed and sustainable decision. It was evidenced that the analysis of multiple criteria was also able to favor the decision-making process in mining dam decharacterization solutions, facilitating traceability and understanding between the stakeholders involved in projects of this nature.
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.
Acesso aberto (Open Access)
Desenvolvimento de uma plataforma de hardware e software livres para monitoramento remoto e instrumentação de barragens
(Universidade Federal do Pará, 2019-08-09) BEZERRA, Ábner Cézar Santos; GOUVEIA, Fernanda Pereira; http://lattes.cnpq.br/1772072130947378; FÜLBER, Heleno; http://lattes.cnpq.br/5018616409948511
This work aims to develop a pilot project of an online Monitoring System for implementation in dam instrumentation, using a platform and free software. The research methodology was carried out in 6 stages, as follows: the literature review; the selection of the development board; the development of a data logger; the development of an application for analog sensor reading; the implementation of the Monitoring System in a controlled environment and the implementation of the Monitoring System in the field. Finally, the conclusions obtained with the elaboration of this research were: the chosen development board, the ESP8266, had a satisfactory performance, being able to be programmed by the Arduino development environment, besides having wifi connection, which allowed the construction of a Data Logger that uses a wireless network, with IP addressing for data presentation. The application created, developed in IDE Android Studio, had satisfactory answer, being able to log in the IP address of the Data Logger, and present the user, in real time, the results on screen. Controlled environment tests were performed to verify the response of a pressure sensor, and in the field, where it was possible to obtain trend curves in each of these environments with great precision, however, by comparing the curves obtained with the curve. standardized calibration, only the convergence of the readings values up to the value of the head height equal to 3 mca was observed, whereas values of head height of 3 to 6 m.c.a. demonstrated approximately 1% dispersion from the standard curve and readings above 6 m.c.a. presented dispersion greater than 5%. This was only possible to identify because the application has a sampling period of 800 milliseconds, thus ensuring a reading in practically real time.
Acesso aberto (Open Access)
Dimensionamento de barragem de acumulação de água para sistema de irrigação de plantio de cacau no sudeste do estado do Pará
(Universidade Federal do Pará, 2024-04-25) SILVA, Cleveland Gustavo Canto; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
The Amazon region has high water potential and large natural reservoirs of water existing in the most diverse forms (springs, aquifers, lakes, etc.), however the distribution and access to the resource by the population are unequal, making the demand for water much greater than its availability in certain regions, which leads to water stress. In the Amazon, family farming is a relevant activity in regional sustainable development, and demands part of this resource, which is a limiting factor for regional development. Faced with this reality, water capture, storage and conservation technologies are used, with dams being one of the available technologies that play an important role in the democratization of water use. Therefore, through this research, we seek to design a dam that will serve as an artificial reservoir for water storage, intended for agricultural consumption of cocoa plantation on an agro-family scale on a farm located in the municipality of Novo Repartimento, to optimize its cultivation cycles, combined with the use of new technologies that use local resources and renewable energy sources available in the Amazon. For this, the water demand necessary for the agricultural activity of the enterprise was evaluated, comprising the Water Balance of the location, as well as delimiting the watershed of direct contribution of the dam, allowing the dimensioning of the artificial reservoir to meet the volume of water needed in the activity.
Acesso aberto (Open Access)
Dosagem experimental de concreto massa com adição de sílica ativa aplicado em barragem
(Universidade Federal do Pará, 2017-11-10) SOUZA, Grazielle Tigre de; GOUVEIA, Fernanda Pereira; http://lattes.cnpq.br/1772072130947378
The study of concrete dosage for large constructions, specifically of dams, has its own peculiarities due to the large volumes involved, intensifying the care with the supply and quality of materials used for these concretes, compositions with pozzolan additions are generally used in order to reduce the heat of hydration. In this sense, the main objective of this research is the elaboration of a mix design of concrete with the substitution of 8% of the cement per silica fume, the experimental study of the mix design was based on the Method of the Fineness Module of the Aggregates. To meet the proposal of this research, the methodology based primarily on the characterization of concrete constituent materials (fine and coarse aggregates, and silica fume), concrete mix design study by the Method of the Fineness Module (MFM) and subsequent analysis of the properties of the concrete mass obtained, making it possible to elaborate the concrete mix design, according to the requirements specified in the design of hydroelectric power plant structures. In this sense, with regard to the characterization of the aggregates, the results demonstrated the feasibility of the use of these in the production of concrete for dams. In relation to cement and silica fume the characteristics of these materials attend the normative requirements. The experimental dosage based on the MFM method, made it possible to compose the dosage graphs needed to define the mix design of concretes and consequently the verification of their applications in dams. It can be affirmed, thus, that the MMF approach developed in this research can be considered an important contribution, for the dissemination of the dosage methodology for concrete application in dams.
Acesso aberto (Open Access)
Estudo de caso de execução de aterros com misturas de argila e rejeito de bauxita
(Universidade Federal do Pará, 2023-06-05) EÇA JUNIOR, José Roberto Guimarães; ALENCAR JÚNIOR, Júlio Augusto de; http://lattes.cnpq.br/3663658632717465
The reuse of mining tailings is a real demand due to the search for sustainable exploitation of resources. Brazil is the holder of one of the largest mineral assets and, as such, is one of the largest producers and exporters of minerals on the planet. The search to meet the demand for the production and extraction of minerals has been growing every day and, along with this growth, the search for the reduction of environmental impact without loss of profitability has also been increasing. Currently, research with these objectives is extremely necessary in the search for solutions to these problems. Several studies seek alternatives for the reuse of the waste on a large scale, and one of the alternatives that make this application feasible are landfills within the enterprise itself. With the continuous updating of the regulations that govern dams, it is often necessary to reinforce old structures in order to increase the safety factor. This paper sought to analyze the applicability of mixing clay with bauxite tailings, in different proportions, for feasibility of its use in controlled landfills. In addition, it aimed to make feasible analyses regarding the research that evidenced the reuse of ore tailings and additions of other tailings materials. A case study was carried out in a mining company, collecting clay and tailings samples, and after being characterized, a pilot and an auxiliary mix were defined. As results, the mixture of 50% bauxite tailings with 50% clay resulted in a material that achieved California Support Index (CSI) values higher than those required by the Dnit 108 of 2009 standards, besides considerably improving the geomechanical characteristics when compared to the pure tailings. Thus, this research contributed to evaluate the applicability of compositions of clay and bauxite tailings in an experimental embankment in a mining area.
Acesso aberto (Open Access)
Interpretação e aplicação dos níveis de controle do monitoramento geotécnico na avaliação de segurança de barragens de mineração
(Universidade Federal do Pará, 2018-05-11) SOUZA, Deni Otávio Oliveira de; LIMA NETO, Aarão Ferreira; http://lattes.cnpq.br/0287664572311345
The importance of monitoring and analyzing dams' safety in reducing the risk imposed by these structures is well known. Structural monitoring aims at various objectives ranging from evaluating the performance against the projected, evaluating the safety of the structure and establishing new theories. However, instrumentation has been increasingly biased to support the stability analysis, and consequently, to limit the safety evaluation of the projects. If it was not enough to limit the role of monitoring in the projects and citations of legislation, it was very important for a tool, called by some professionals as a risk chart, which establishes levels of control, attention, alert and emergency related to reading of each instrument. However, these control or reference levels may be being used widely and mistakenly to determine dam safety by overlapping or superseding judgment by engineering professionals in many cases. In addition, criteria for the application of a methodology for the elaboration of levels of control through the deterministic method were presented, considering the instruments that make up the main section of a mining dam, applying a methodology to define the levels of attention, alert and instrument, in order to assist in the prior analysis of the structure monitoring data and to automatically identify possible deviations in the instrument reading pattern. In this way, limits were established for the control levels of the instruments and the results obtained were used in the implementation of a pre-alarm system associated to a standard response procedure in relation to the level of control informed, with the purpose of improving the control and safety of the structure. Finally, this work sought to reflect on the application of this monitoring control tool in the safety of mining dams, making a critical analysis of technical concepts applied to the risk analysis of the structure, which led to a conclusion that the nomenclatures used for control levels and widely used risk charts should be reviewed so that they are not mistakenly associated with the risk of the structure or the Emergency Action Plans of mining dams.
Acesso aberto (Open Access)
Investigação da causa da fratura na haste do cilindro hidráulico da comporta do vertedouro da UHE Tucuruí
(Universidade Federal do Pará, 2018-08-16) MOREIRA, Davi Carvalho; MERLIN, Bruno; http://lattes.cnpq.br/7336467549495208
This research presents an investigation of the causes of the fracture in a piston rod of he hydraulic cylinder that moves the spillway floodgate of the hydroelectric power plant of Tucuruí, after 30 years of service. The chemical analysis and tensile tests confirmed that the piston rod material meets the design specification corresponding to AISI 410 martensitic stainless steel, with J-Factor and P-Factor indicating that the material is susceptible to temper embrittlement. The analysis of the fractured surface, using a scanning electron microscope, showed a totally martensite structure with δ-ferrite, promoting a strong negative effect on the mechanical properties of the steel, reducing impact resistance and crack propagation energy. The impact tests, on Charpy-V test specimens, indicated low tenacity for the studied piston rod. The metallographic analysis showed an intergranular fracture with cleavage signals, crack propagation along the outlines of the previous austenite and an intense intergranular corrosion along the surface of the piston rod. The stress measurement in the piston rods of the hydraulic cylinders, in a real service situation, showed that the stress in the section of larger diameter of the piston rod, during the floodgate opening, is lower than design values, and the stress amplitude variation, caused by water passing through the floodgate, has values less than 1% of the nominal stress. The results btained in the field test were used in numerical studies modeled by the Finite Element Method, observing a stress of approximately 63% of the yield stress of the material and infinite life for low cycle fatigue (opening and closing of the floodgate) and very high cycle fatigue (water passing through the floodgate) in the place where the fracture occurs. The piston rod failed due to low impact tenacity and moderate corrosion resistance, associated with the notch effect of the critical transition zone of the piston rod section. These conditions, together with the corrosive effect of the water, led to crack nucleation under stress corrosion and propagation through fatigue, until the total brittle failure. The performance of the piston rod comes from inadequate heat treatment during the manufacturing process, which resulted in high δ-ferrite content, temper embrittlement, low impact tenacity and susceptibility to stress corrosion.
Acesso aberto (Open Access)
Mapas de inundação em área urbana na cidade de Araguaína/TO: estudo de caso da interferência da CGH Corujão
(Universidade Federal do Pará, 2022-02-25) SANTANA, Leonardo Moreira; SILVA, Adriano Frutuoso da; http://lattes.cnpq.br/3321059172343690; https://orcid.org/0000-0003-1710-8862
The habitation occupation in the area of influence of CGH (hydroelectric power station) - Corujão is quite significant, however, there is an imminent risk of flooding in the area, a factor that motivated the development of the study, to understand the real risks incident on the area. Therefore, this work aimed to analyse the impacts of the CGH Corujão dam reservoir in the urban area of the city of Araguaína/TO. A data collection and characterization of the Neblina stream, which flows into the CGH reservoir, were carried out to understand how the occurrence of high levels of rain causes the stream to overflow and increase the risks of flooding in an urban area, being calculated the maximum rainfall. With these data, a simulation was performed using the HEC-RAS program, which led to the generation of flood maps. Regarding the impacts of the dam reservoir in the urban area of the city, it was possible to observe that it has little influence in the flood areas, according to the maps obtained from the aplicativo HEC-RAS. From the results it was possible to verify that most of the maps presented risks to human life and structural damage. These data show that it is an area of vulnerability to floods and, consequently, to life, health, infrastructure, economy and socioeconomic development. The estimated contributions of the study involve the population and the government. The identification of areas of greater vulnerability in terms of failures and collapses of masonry structures, essential information for the development of a master plan in which these areas of greater risk are excluded from use for housing, commerce, services and other activities. With access to the full risk map, the city has the possibility to develop future housing programs so that the existing structures are deactivated and companies, residences, services and others are directed to other areas, with safety and guarantee of rights. Urban planning, in activities such as drainage studies, needs this information so that they can be developed in an assertive and effective way, benefiting the public administration, by avoiding damages that need to be corrected and require resources, in addition to improving the infrastructure of services and making the daily life of citizens safer. The civil defence, in possession of the data obtained, can develop support programs for the residents of the region, issue risk alerts more broadly in the face of the forecast of intense rains and floods, allowing individuals who are in these areas to seek more safe for these moments of risk. With this study, it is possible to define risk reduction approaches that guarantee more health for the population, reduce the demand for resources for health care after the floods, as well as reduce the occupancy of beds for the sick and injured due to the floods. In view of the above, it appears that the benefits are numerous, both for the population and for the public administration, with a reduction in expenses and costs to the public coffers, in addition to a greater guarantee of preservation of the life and patrimony of individuals who, in the present, live in areas of high vulnerability.
Acesso aberto (Open Access)
Metodologia de seleção de rotas de evacuação de emergência para caso de rompimento da UHE-Tucuruí
(Universidade Federal do Pará, 2019-01-30) GOTO, Raphaela Sobreira; TEIXEIRA, Marcelo Rassy; http://lattes.cnpq.br/8912916360456192
Dams play an important role in Brazilian social and economic development. Although even when considered low risk, incidents involving dams can cause significant damage, and despite several potential costs resulting from material damages, the loss of a human life is the most meaningful in damage scale. Evacuation in case of disruption is a complex process that is the aggregated result of many factors, such as evacuation mode and characteristics of evacuation routes. In this context, the present work aims to determine a methodology for selecting emergency evacuation routes for the urban area of Tucuruí municipality located downstream of Tucuruí Hydroelectric Power Plant (UHE-Tucuruí), regarding the condition of a dam failure only. The methodology adopted is based on the optimization of evacuation routes, minimizing and/or excluding intersections along the way, this proposal follows an adaptation of route selection method developed by Zhang et al. (2016). The methodology was applied in four stages, the first was the division of the municipality into manageable zones according to the socioeconomic characteristics and road distribution, the second was the creation of the intersection table (adjacency) between the roads, the third was the determination of the exit routes, responsible for the displacement of the population to another municipalities and the fourth was the development of route selection method that has as a final product, a table of evacuation routes considering all possible exits of high risk area. The method establishes as the best route choice the one with the fewest intersections in the evacuation path. As a result, the methodology proved to be effective when applied in Tucuruí, generating possible evacuation routes within the entire urban perimeter of the municipality, providing affordability since it does not use software that requires a license and high application cost, being showed as a method of easy acceptability and communication among the population to be evacuated, providing time travel reduction, safer evacuation and traffic load balance between different exits.
Acesso aberto (Open Access)
Metodologia para preparação e avaliação de resposta a simulados de emergência de barragem de mineração
(Universidade Federal do Pará, 2018-05-11) DIAS, Rogério Eduardo Souza de Almeida; GOUVEIA, Fernanda Pereira; http://lattes.cnpq.br/1772072130947378
Mining dams are fundamental elements for the process of mineral processing due to the need to concentrate or separate the mineral components of economic interest from the economically unusable components (mining tailings). In order for the tailings to be stored, the reservoirs of dams built in the mining projects for this purpose are commonly used. Over time, dams accumulate large volumes of tailings and water become susceptible to undesirable situations, such as diverse anomalies and failures. In this context, the present research has the objective of presenting a methodology for the preparation and evaluation of response to the Table Top and Full Scale simulated emergency simulations from the PAEBM of the Pera Jusante mining dam, located in the municipality of Parauapebas, state of Pará. The motivation of the work proposal was based on bibliographical research that indicated the lack of methodologies for the application of emergency simulation with mining dams. The methodology was developed based on three stages, the first being the presentation of the dam case study (including the downstream area), the second the execution of the emergency simulation and the third the evaluation of the efficacy of the simulated. The preparation verification methodology used international simulation concepts of emergencies in a gradual and adapted way for dams, starting with the Table Top Exercise and then performing the simulated exercise of full scale field evacuation. During the execution phase of the simulation, guides were prepared to help prepare both the agents involved and the population exposed to the flood spot. In order to record the information of the emergency simulation, it was proposed the use of files containing the details of the emergency situations, the expected responses and other information for the conduct of the simulations. As results obtained it is possible to emphasize that in the stage of execution of the simulated it was possible to know the capacity to respond to a possible emergency situation in the dam case study, with a response from the point of view of the very positive researcher, since it met the (Table Top Exercise) and 93.33% for the Full Scale Exercise simulation. The present research can be applied to any mining dam that has a PAEBM designed and is expected to contribute to the improvement of the methodologies of preparation and response to emergencies with mining dams, being used to improve the process of mining companies that already practice similar actions, and above all, mining companies that are still starting work on emergency preparedness and response to the safety of the downstream population.