Navegando por Assunto "Estrada de Ferro Carajás"

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Acesso aberto (Open Access)
Em busca de carvão vegetal barato: o deslocamento de siderúrgicas para a Amazônia
(2006-12) MONTEIRO, Maurílio de Abreu
The article analyzes the process the installation and operation, in the Eastern Brazilian Amazon area, of merchant pig iron producers the past two decades. In a smaller number and in a slower rhythm than expected by the state planners, twelve producers have settled in the Carajas Railroad Corridor. A merchant pig iron production requires high amounts of energy, supplied by charcoal. The article indicates meant an industry migration to that region whereas, until the 90’s, such producers were almost exclusively located in the Brazilian southeast, and that the charcoal demand is the main link between the industrial plants and the regional socio-economy. The charcoal production has resulted in many social and environmental impacts. Impacts materialized by the big pressure on the Amazon rain forest through imprudent environmental practices, and by charcoal production supported by precarious labor conditions, unhealthy working environment, and low wages. Such a scenario draw one alternative: the maintenance of pig iron production using the current patterns and the attachment of electric arc furnace on the existents blast furnaces in order to produce steel. At end the article appoints that the installing minimills do not solve the main socioenvironmental problem in the region: the processing of iron ore linked to the harmful effects caused by charcoal production. On the contrary, they can be even worsened.
Acesso aberto (Open Access)
Fatigue lifetime of a RC bridge along the Carajás railroad
(Universidade Federal do Pará, 2012-10) SANTOS, Régis Rivo Ferreira dos; OLIVEIRA, Dênio Ramam Carvalho de
The aim of this paper is to present and discuss the results obtained with a methodology used to characterize the concrete and to evaluate the structural safety against fatigue of the reinforced concrete bridge number 50A located in the Carajás railroad. An “in situ” inspection was carried out in order to assess the evolution of damage in structural elements, with reference to information available in existing projects, calculation memory and reporting of previous inspections. Extractions of concrete testimonies, alkalinity tests, sclerometry, pacometry and laboratory tests were also performed to characterize the materials mechanically and estimate the structural behavior of the bridge under higher future loads.
Acesso aberto (Open Access)
Structural assessment of a RC Bridge over Sororó river along the Carajás railway
(Universidade Federal do Pará, 2015-04) MATOS, José Cristino Lima de; BRANCO, Vitor Hugo Lopes; MACÊDO, Alcebíades Negrão; OLIVEIRA, Dênio Ramam Carvalho de
The Carajás railway is operated by Vale SA and is used to transport the Brazilian production of iron ore mine located in the state of Pará until Itaqui harbor in Maranhão state. With 892 km in length, the railway will be doubled due to the prospect of increased production, which requires verification of the structures of bridges to ensure safety under loading up to 23% larger. The railway bridge in reinforced concrete has five hyperstatic spans with 25 m long and was built over Sororó river in the southeast of Pará. To better evaluate its structural performance under current loadings, several structural elements were monitored with strain gages and the concrete was characterized by non-destructive and destructive testing on the structure. This information was used in a computer model to estimate the future structural behavior. The methodology was satisfactory as the estimated structural performance for future loadings, meeting the recommendations of the Brazilian technical standards.