896 resultados para Infrastructure and Construction Projects


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Mestrado em Finanças

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The exposure to dust and polynuclear aromatic hydrocarbons (PAH) of 15 truck drivers from Geneva, Switzerland, was measured. The drivers were divided between "long-distance" drivers and "local" drivers and between smokers and nonsmokers and were compared with a control group of 6 office workers who were also divided into smokers and nonsmokers. Dust was measured on 1 workday both by a direct-reading instrument and by sampling. The local drivers showed higher exposure to dust (0.3 mg/m3) and PAH than the long-distance drivers (0.1 mg/m3), who showed no difference with the control group. This observation may be due to the fact that the local drivers spend more time in more polluted areas, such as streets with heavy traffic and construction sites, than do the long-distance drivers. Smoking does not influence exposure to dust and PAH of professional truck drivers, as measured in this study, probably because the ventilation rate of the truck cabins is relatively high even during cold days (11-15 r/h). The distribution of dust concentrations was shown in some cases to be quite different from the expected log-normal distribution. The contribution of diesel exhaust to these exposures could not be estimated since no specific tracer was used. However, the relatively low level of dust exposure dose not support the hypothesis that present day levels of diesel exhaust particulates play a significant role in the excess occurrence of lung cancer observed in professional truck drivers.

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Coffee and cocoa represent the main sources of income for small farmers in the Northern Amazon Region of Ecuador. The provinces of Orellana and Sucumbios, as border areas, have benefited from investments made by many public and private institutions. Many of the projects carried out in the area have been aimed at energising the production of coffee and cocoa, strengthening the producers’ associations and providing commercialisation infrastructure. Improving the quality of life of this population threatened by poverty and high migration flows mainly from Colombia is a significant challenge. This paper presents research highlighting the importance of associative commercialisation to raising income from coffee and cocoa. The research draws on primary information obtained during field work, and from official information from the Ministry of Agriculture. The study presents an overview of current organisational structures, initiatives of associative commercialisation, stockpiling of infrastructure and ownership regimes, as well as estimates for both ‘robusta’ coffee and national cocoa production and income. The analysis of the main constraints presents different alternatives for the implementation of public land policies. These policies are aimed at mitigating the problems associated with the organisational structure of the producers, with processes of commercialisation and with environmental aspects, among others.

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For a variety of reasons, the concrete construction industry is not sustainable. First, it consumes huge quantities of virgin materials. Second, the principal binder in concrete is portland cement, the production of which is a major contributor to greenhouse gas emissions that are implicated in global warming and climate change. Third, many concrete structures suffer from lack of durability which has an adverse effect on the resource productivity of the industry. Because the high-volume fly ash concrete system addresses all three sustainability issues, its adoption will enable the concrete construction industry to become more sustainable. In this paper, a brief review is presented of the theory and construction practice with concrete mixtures containing more than 50% fly ash by mass of the cementitious material. Mechanisms are discussed by which the incorporation of high volume of fly ash in concrete reduces the water demand, improves the workability, minimizes cracking due to thermal and drying shrinkage, and enhances durability to reinforcement corrosion, sulfate attack, and alkali-silica expansion. For countries like China and India, this technology can play an important role in meeting the huge demand for infrastructure in a sustainable manner.

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Bridge approach settlement and the formation of the bump is a common problem in Iowa that draws upon considerable resources for maintenance and creates a negative perception in the minds of transportation users. This research study was undertaken to investigate bridge approach problems and develop new concepts for design, construction, and maintenance that will reduce this costly problem. As a result of the research described in this report, the following changes are suggested for implementation on a pilot test basis: • Use porous backfill behind the abutment and/or geocomposite drainage systems to improve drainage capacity and reduce erosion around the abutment. • On a pilot basis, connect the approach slab to the bridge abutment. Change the expansion joint at the bridge to a construction joint of 2 inch. Use a more effective joint sealing system at the CF joint. Change the abutment wall rebar from #5 to #7 for non-integral abutments. • For bridges with soft foundation or embankment soils, implement practices of better compaction, preloading, ground improvement, soil removal and replacement, or soil reinforcement that reduce time-dependent post construction settlements.

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This booklet will help developers, consultants, and engineers planning concrete pavement construction projects, superintendents and supervisors who want a basic training aid and reference, and crew members new to the concrete paving industry. It provides a general description of current concrete pavement construction practices, from establishing preconstruction control mechanisms to sealing joints. It also provides a quick troubleshooting reference.

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In recent years, thin whitetopping has evolved as a viable rehabilitation technique for deteriorated asphalt cement concrete (ACC) pavements. Numerous projects have been constructed and tested; these projects allow researchers to identify the important elements contributing to the projects’ successes. These elements include surface preparation, overlay thickness, synthetic fiber reinforcement usage, joint spacing, and joint sealing. Although the main factors affecting thin whitetopping performance have been identified by previous research, questions still existed as to the optimum design incorporating these variables. The objective of this research is to investigate the interaction between these variables over time. Laboratory testing and field-testing were planned in order to accomplish the research objective. Laboratory testing involved shear testing of the bond between the portland cement concrete (PCC) overlay and the ACC surface. Field-testing involved falling weight deflectometer deflection responses, measurement of joint faulting and joint opening, and visual distress surveys on the 9.6-mile project. The project was located on Iowa Highway 13 extending north from the city of Manchester, Iowa, to Iowa Highway 3 in Delaware County. Variables investigated included ACC surface preparation, PCC thickness, synthetic fiber reinforcement usage, and joint spacing. This report documents the planning, equipment selection, construction, field changes, and construction concerns of the project built in 2002. The data from this research could be combined with historical data to develop a design specification for the construction of thin, unbonded overlays.

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Around 11.5 * 106 m3 of rock detached from the eastern slope of the Santa Cruz valley (San Juan province, Argentina) in the first fortnight of January 2005. The rockslide?debris avalanche blocked the course, resulting in the development of a lake with maximum length of around 3.5 km. The increase in the inflow rate from 47,000?74,000 m3/d between April and October to 304,000 m3/d between late October and the first fortnight of November, accelerated the growing rate of the lake. On 12 November 2005 the dam failed, releasing 24.6 * 106 m3 of water. The resulting outburst flood caused damages mainly on infrastructure, and affected the facilities of a hydropower dam which was under construction 250 km downstream from the source area. In this work we describe causes and consequences of the natural dam formation and failure, and we dynamically model the 2005 rockslide?debris avalanche with DAN3D. Additionally, as a volume ~ 24 * 106 m3of rocks still remain unstable in the slope, we use the results of the back analysis to forecast the formation of a future natural dam. We analyzed two potential scenarios: a partial slope failure of 6.5 * 106 m3 and a worst case where all the unstable volume remaining in the slope fails. The spreading of those potential events shows that a new blockage of the Santa Cruz River is likely to occur. According to their modeled morphometry and the contributing watershed upstream the blockage area, as the one of 2005, the dams would also be unstable. This study shows the importance of back and forward analysis that can be carried out to obtain critical information for land use planning, hazards mitigation, and emergency management.

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This report summaries the work of the committee over the last year and its vision for the future. The committee is followed with interest the work of the Department of Corrections and the Department of Veterans Affairs in evaluating the needs of their facilities and recommends similar evaluations of facilities around the state by other agencies. The committee members are ready to offer advice on the needs of the state's again infrastructure and steps that could be taken to evaluate vacant and underutilized buildings and reduce operational and maintenance costs.

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Esta dissertação tem por finalidade evidenciar os “Impactos Decorrentes da Expansão da Cidade de Assomada”. Propõe-se ainda, analisar a relação urbanorural no município de Santa Catarina, Cabo Verde. Essa análise incidiu sobre os dados da sua ocupação, que remonta à 2ª metade do século XIX, no decurso da crise e decadência da primeira cidade de Cabo Verde (Ribeira Grande, atual Cidade- Velha) e às conjunturas regionais e nacionais que condicionaram sua trajetória, bem como, os principais agentes intervenientes na transformação do espaço urbano de Assomada (Estado, proprietários de terra e comerciantes), sobretudo, no período que decorre de 1961 a 2003. A pesquisa empreendida demonstra que a “ruralidade” é um dos aspectos fundamentais de Santa Catarina, abrangendo 21,3% da população rural do território nacional e 37,9% da ilha de Santiago. Do ponto de vista urbanístico, o mapeamento da evolução da cidade de Assomada, referente à área ocupada pelas edificações nesse lapso de tempo, permite-nos perceber um crescimento bastante acelerado desse espaço urbano, sobretudo, a partir dos anos 90. Dois aspectos importantes se encontram na base dessa transformação: a Independência Nacional ocorrida em 1975 e a Emigração. Com a Independência, o país passou a beneficiar de amplos programas de cooperação internacional o que veio a reforçar a sua importância econômica e política, visualizada através de projetos industrializantes, infra-estruturas e equipamentos de diversas naturezas. Esses investimentos foram por sua vez reforçados por aportes dos emigrantes, que passaram a ser um dos parceiros fundamentais no desenvolvimento de Santa Catarina, através de iniciativas privadas e empresariais, como a construção de residências e constituição de empresas. A análise do indicador uso e ocupação do solo urbano permitiu-nos identificar alguns impactos ambientais causados, sobretudo, pela falta de instrumentos de gestão urbanística, ausência de cadastro municipal e uma deficiente fiscalização dos órgãos administrativos.

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This report summaries the work of the committee over the last year and its vision for the future. The committee is followed with interest the work of the Department of Corrections and the Department of Veterans Affairs in evaluating the needs of their facilities and recommends similar evaluations of facilities around the state by other agencies. The committee members are ready to offer advice on the needs of the state's again infrastructure and steps that could be taken to evaluate vacant and underutilized buildings and reduce operational and maintenance costs.

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This manual captures the experience of practitioners in the Iowa Department of Transportation’s (Iowa DOT’s) Office of Location and Environment (OLE). It also documents the need for coordinated project development efforts during the highway project planning, or location study phase and engineering design. The location study phase establishes: * The definition of, and need for, the highway improvement project * The range of alternatives and many key attributes of the project’s design * The recommended alternative, its impacts, and the agreed-to conditions for project approval The location study process involves developing engineering alternatives, collecting engineering and environmental data, and completing design refinements to accomplish functional designs. The items above also embody the basic content required for projects compliant with the National Environmental Policy Act (NEPA) of 19691, which directs federal agencies to use a systematic, interdisciplinary approach during the planning process whenever proposed actions (or “projects”) have the potential for environmental impacts. In doing so, NEPA requires coordination with stakeholders, review, comment, and public disclosure. Are location studies and environmental studies more about the process or the documents? If properly conducted, they concern both—unbiased and reasonable processes with quality and timely documents. In essence, every project is a story that needs to be told. Engineering and environmental regulations and guidance, as documented in this manual, will help project staff and managers become better storytellers.

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Recognize that plans and proposals are not currently available for the following projects. The letting dates indicated are estimated target dates only and they are subject to change

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This report summaries the work of the committee over the last year and its vision for the future. The committee is followed with interest the work of the Department of Corrections and the Department of Veterans Affairs in evaluating the needs of their facilities and recommends similar evaluations of facilities around the state by other agencies. The committee members are ready to offer advice on the needs of the state's again infrastructure and steps that could be taken to evaluate vacant and underutilized buildings and reduce operational and maintenance costs.

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This report summaries the work of the committee over the last year and its vision for the future. The committee is followed with interest the work of the Department of Corrections and the Department of Veterans Affairs in evaluating the needs of their facilities and recommends similar evaluations of facilities around the state by other agencies. The committee members are ready to offer advice on the needs of the state's again infrastructure and steps that could be taken to evaluate vacant and underutilized buildings and reduce operational and maintenance costs.