Rio-Niteroi Bridge Research Articles

The eutrophication process in the lagoon systems of eastern Rio de janeiro investigated through the analysis of sedimentary phosphorus and historic of basin occupation

Lagoons along the eastern coast of Rio de Janeiro serve as vital corridors for the preservation of marine and coastal biodiversity. However, these ecosystems are facing substantial threats stemming from environmental degradation and cultural eutrophication. This study aims to investigate the process of eutrophication by analyzing sedimentary environments in coastal lagoons located in the municipalities of (Itaipu) Niterói, (Fora) Saquarema, and Araruama (São Pedro da Aldeia). The investigation involves the analysis of sedimentary records collected at various times in each lagoon, with particular focus on phosphorus content and grain size distribution, emphasizing silt, clay and sand fractions. These analyses are correlated with the historical population growth in the drainage basins. Our working hypothesis posits that the impacts of urbanization on the degradation of lagoon systems are archived within the sedimentary records. It is anticipated that the extent and magnitude of these impacts are correlated with population density. The notable increase in demographic density can be attributed to the inauguration of the Rio-Niteroi Bridge, resulting in a significant influx of residents and tourists into the coastal region in question. This hypothesis is supported by census data, which reveal substantial population growth in coastal areas. In addition, this study utilizes ordination analysis, specifically Principal Component Analysis (PCA), to classify sedimentary layers based on their depositional characteristics. The PCA allows for the categorization of sedimentary data, unveiling changes in erosion and sedimentarion patterns. Remarkably, our research stablishes a significant correlation between the escalating total phosphorus fluxes and population growth, thereby providing valuable insights into the historical progression of cultural eutrophication within the coastal lagoon systems of eastern Rio de Janeiro. Overall, our findings contribute to an enhanced understanding of how urbanization and population dynamics have influenced the eutrophication process within there vital coastal ecosystems over the past five decades.

“Ciganos da construção”: a divulgação de acidentes de trabalho na construção civil pela imprensa durante a ditadura militar brasileira

Partindo da concepção de que os acidentes e doenças do trabalho representam a culminância do processo de exploração capitalista e, portanto, têm o potencial de revelar as condições de vida e trabalho vigentes nas conjunturas estudadas, o presente artigo discute como os índices oficiais de sinistros laborais elaborados pela Previdência Social, e demais questões relacionadas à infortunística, foram tratados pela imprensa nos primeiros anos da década de 1970, sobretudo pelos jornais O Estado de São Paulo, Opinião e Movimento. De forma complementar, também serão evocadas algumas fontes oficiais ligadas ao Ministério do Trabalho, e que, portanto, veiculavam o posicionamento oficial do governo no campo da sinistralidade laboral. Com enfoque nos “ciganos das construções”, como eram chamados os operários da construção civil, setor que passou por notável expansão durante o período, buscaremos apontar alguns aspectos que muito revelam sobre o modelo de desenvolvimento excludente adotado pela ditadura militar, baseado na super-exploração da força de trabalho e no favorecimento ao grande capital: a migração, a informalidade, a fiscalização dos ambientes de trabalho, a extensão das jornadas, a pressão pelo cumprimento de prazos, o desrespeito pelas normas de higiene e segurança do trabalho, a descartabilidade das vidas dos trabalhadores – tanto nas obras de pequeno porte quanto nas grandes catástrofes, como a Gameleira e a ponte Rio-Niterói.

Análise da Influência da Presença de Veículos de Grande Porte no Comportamento Aerodinâmico e Aeroelástico de Estrutura de Ponte

Estruturas de pontes flexíveis são frequentemente suscetíveis à ação dinâmica do vento, apresentando os chamados fenômenos aeroelásticos causados pela interação entre as forças inerciais, elásticas e as aerodinâmicas. A ocorrência desse tipo de oscilação pode gerar danos estruturais e desconforto aos usuários. Tradicionalmente, o estudo dos efeitos dinâmicos do vento em estruturas era feito apenas por meio de experimentos em túneis de vento. Atualmente, utilizam-se também análises com modelos numéricos por meio da fluidodinâmica computacional (CFD – ComputationalFluid Dynamics).Utilizando uma ferramenta computacional em Dinâmica dos Fluidos, avaliam-se, no presente trabalho, os efeitos do vento no comportamento aerodinâmico da ponte Rio-Niterói, quando esta tem seu perfil não aerodinâmico alterado pela presença de veículos de grande porte. A comparação entre registros de grandes oscilações da ponte sugere que a alteração do seu perfil pela presença de veículos de grande porte pode contribuir para tornar mais intensa a oscilação induzida pelo desprendimento cadenciado de vórtices. Primeiramente, apresentam-se os resultados para as estruturas em repouso sob a ação do vento. Consideram-se os perfis da ponte, de dois tipos de veículos e do conjunto ponte mais veículo. Na sequência, apresentam-se os resultados para a seção da ponte, com e sem veículo, em movimento, em termos das histórias no tempo de amplitude de vibração em função das velocidades de vento. Os resultados obtidos para a seção dos veículos e para a ponte sem veículo, tanto em repouso quanto em movimento, compararam-se bem com os respectivos resultados experimentais. Isto permitiu a avaliação do comportamento aerodinâmico da ponte com os veículos, atestando que este perfil contribui para o aumento das vibrações com a ação do vento.

Biomonitoring of Polycyclic Aromatic Hydrocarbon in Perna perna from Guanabara Bay, Brazil

The goal of the present work was to test the response of Perna perna to oil contamination in the marine environment. Mussels Perna perna were collected on several occasions from the pillars of Rio-Niteroi Bridge, Guanabara Bay, Rio de Janeiro, including after a major spill of MFO380 in January 2000. Condition index evaluation and neutral red assay were carried out in these mussels, which were also tested for polycyclic aromatic hydrocarbons (PAHs) concentration by using GC/MS. The PAH burden in mussels, analyzed before and after the oil spill, increased between 2 and 5 fold. This change was dominated by measurable increases in naphthalene, phenanthrene, dibenzothiophene, and their respective alkylated homologs. Although indicative ratios revealed petrogenic contamination after the spill, source indicative ratios for PAHs in the mussels differ from that for the oil. In agreement to what is reported in the literature for other bivalves, Perna perna responds reliably to variations in oil derived PAHs in the environment, proving to be a suitable biomonitor of petroleum contamination. Neutral red assay turned out to be a sensitive biomarker of alterations in mussels exposed to oil and made evident the occurrence of threshold reaction triggered by higher levels of contamination.

Strategy for passengers' transport effectiveness and competitiveness: multimodality for Rio de Janeiro metropolis

The focus of this paper is an analysis of one of the main transport corridors between Rio de Janeiro (the main centrality), Niteroi (second metropolitan centrality) and Sao Goncalo (one of the biggest suburban areas). The metropolitan area of Rio de Janeiro, with its residential sprawl ad concentration of economic activities in the central district, induced the radio concentric transportation infrastructure and led to its ineffective use. The main bus transit has been facing a perspective of rising operational and environment costs, given saturated physical capacity of Rio-Niteroi Bridge situated on Guanabara Bay. There is also a lack of transport planning policy oriented to sustainable urban development. The National Bank for Economic and Social Development has supported two studies aimed to develop transport alternatives for this corridor. The one has proposed a rapid Metro line and second one, with the goal of urban restructuring, has resulted in a multimodal alternative, called Acqua Ro-Ro, catamarans and embarked vehicles�roll-on/roll-off�exclusive for buses already existing within the formal public transport system, which attend connections crossing the Guanabara Bay. This alternative contributes to the competitiveness of the bus system and demands 10% of the investments estimated for the Metro construction. There are also positive environmental impacts and reduced institutional constraints, making this alternative more attractive.

A stabilized finite element procedure for turbulent fluid–structure interaction using adaptive time–space refinement

AbstractThis paper presents our effort to addressing fluid–structure interaction (FSI) problems by means of computational mechanics. A stabilized finite element formulation is used to solve the incompressible Navier–Stokes equations written in primitive variables. The structure is modelled using rigid‐body dynamic equations solved using a Runge–Kutta method. The distinctive feature of our approach is the combination of large eddy simulation (LES)—based on implicit turbulence modelling—with time–space adaptive techniques in arbitrary Lagrangian Eulerian co‐ordinates (ALE). Three representative numerical examples are presented. The first one is the simulation of turbulent vortex shedding around a fixed obstacle, comparing our two‐dimensional (2D) LES results with experiments and more refined three‐dimensional (3D) numerical solutions. The second example presents an ALE computation with moving boundaries, where we were able to detect the lock‐in phenomenon for an oscillating cylinder driven by periodic vortex shedding. Our final example is the FSI problem associated to the flow around a dominant central span section of the Rio‐Niterói bridge, where we compare our results with experiments performed in a wind tunnel. Copyright © 2004 John Wiley & Sons, Ltd.

Elevated Link Road in Rio de Janeiro, Brazil

An elevated roadway, 1.4 km long and covering 8500 m², was opened to traffic in March 1998 after a construction period of 18 months. The roadway links three existing elevated roadways (the Red Line, the Perimetral Line and the Rio-Niteroi Bridge access) in Rio de Janeiro. Belly-shaped post-tensioned precast concrete beams and partially precast slabs were used to construct the roadway. A new device for joining the new roadway with the existing ones was applied successfully.

CONSTRUCTION OF THE NAVIGATION SPANS OF THE RIO NITEROI BRIDGE, BRAZIL.

Keywords HOWARD NEEDLES TAMEN & BERGENDOFF REDPATH DORMAN LONG, CLEVELAND BRIDGE AND ENGINEERING, MONTREAL ENGENHARIA CONSTRUCTION, SPANS, FABRICATION, LARGE, GIRDERS, CONCRETE, ORTHOTROPIC, WELDED, SECTIONS, RING, JACKING, CAPACITY, STEELWORK, WORKS, THREE SPAN, CONTINUOUS, MANAGEMENT, FINISHING, BRIDGES, COUNTRIES, ERECTION, STEEL, CENTRE, LANES, DECKS, SITES, SIDES, PIERS, EQUIPMENT, TENSION, WELDING, DESIGN, RELIEF, PRECAST, PLANNING, MAIN, NAVIGATION, DEVELOPING, ASSEMBLY, BOX, TWIN, TRAFFIC, SURFACING, FLOATING, TEMPORARY, BASES, JACKING UP, MEMBERS, LIFTING, PERMANENT, STRESS, PRESTRESSED, CONTRACTS, PONTOONS RIO NITEROI, NITEROI, RIO DE JANEIRO, GUANABARA BAY BRAZIL, SOUTH AMERICA... Show All

The technique of glueing precast elements of the Rio-Niteroi bridge

The prestressed concrete superstructure of the 7,884 m long and 26.6 m wide bridge over the Guanabara Bay, connecting the cities of Rio de Janeiro and Niteroi, in Brazil, was constructed by the cantilever method with the help of precast segments which were glued together with epoxy resin. An experimental investigation of the structural behavior of the glued joints was made in a model of the bridge. Important conclusions resulted from the experiment. It has been shown that the glued joints do not affect the safety of the structure. Several investigations were made during the construction for determination of various important features of the glued joints for erection procedures. The behavior of glued joints was studied with the help of a specially developed concrete test piece.