Search

This paper presents the results of an elastoplastic finite-element back analysis of an excavation made on a saturated soft organic clay deposit in Rio de Janeiro, Brazil. The excavation was conducted as part of an urbanization program, in which artificial islands were to be created in a swamp along the margins of the Camboinhas Lagoon. An extensive laboratory testing program was performed on undisturbed soil samples to characterize the stress-strain-strength behavior of the involved materials. Results from this laboratory testing program were used to calibrate a nonassociated elastoplastic constitutive model implemented in the ANLOG (Nonlinear Analysis of Geotechnical Problems) code. This code is based on the finite-element method and is capable of conducting fully coupled analyses by using a variety of constitutive models. Coupled analyses were performed to simulate the Camboinhas excavation, which was conducted under plane strain condition. Field measurements of both displacements and pore-water pressures obtained during the excavation are compared with the results of the numerical simulation. Analyses of the results show that monitored in situ and numerical results are in good agreement. [ABSTRACT FROM AUTHOR]

This paper presents results from physical model testing of lateral clay-pipe interaction. The main reason for this research was the accident in Rio de Janeiro in January 2000 when more than 1×106 l of crude oil was spilled into Guanabara Bay due to thermal buckling of a pipeline. A set of centrifuge tests was performed for a model pipeline at shallow burial depths in order to assess the lateral resistance of the soft clay from the incident site. In addition, a set of 1-g model tests was also performed to observe the failure mechanism in more detail. These tests permitted the development of an analytical model, based on geotechnical and geometrical parameters, able to evaluate the soil resistance when subjected to lateral pipe movements for shallow burial depths. The centrifuge data are then compared with the proposed analytical model and with literature data, revealing good agreement in both cases. [ABSTRACT FROM AUTHOR]

The growth of megaevents is related to changes within urban management paradigms and the corresponding economic analysis. As such, urban management and macroeconomic policy must be investigated together. This paper focuses on the relationships between the hosting of the 2007 Pan American (Pan Am) games, the budget management of Rio de Janeiro city, and Brazil's macroeconomic policy, considering both the economic impacts and exploring possible alternative uses of the public resources. The games required a newly built infrastructure, demonstrating that hosting megaevents in developing countries requires more sacrifices than for cities in industrialized countries. These expenditures did not change the control policy of public debt, because the city's management followed the principles of government policy. Therefore, the adjustment of the municipal budget occurred in other expenditures, especially health and education. Finally, Rio de Janeiro municipality did not have enough resources to host the Pan Am games, and the federal government had to promise financial support. Planning megaevents has a new dimension not usually discussed in the economic impact literature: the consequences of megaevents on the federalist equilibrium. [ABSTRACT FROM AUTHOR]

Different approaches related with urban flood problems treatment are evolving and there is a large set of possible engineering measures that can be applied. Lately, the traditional approach, focusing on improving channel conveyance, is being complemented by distributed structural measures and nonstructural measures, considering the basin under a systemic point of view and aiming to recover natural flow patterns prior to urbanization. In this context, it becomes necessary to evaluate the potential use of different combinations of the possible interventions, in such a way that the efficacy of these sets in terms of flood mitigation can be optimized. This kind of analysis is of crucial importance and involves technical and economic aspects. Combined effects of the chosen measures may produce a result that is not equivalent to what would be expected from the summation of its individual effects. The systemic behavior of an urban watershed, especially when the drainage system works jointly with flooded urban landscape elements, makes it possible that some design solutions become to act in a noneffective way. Sometimes, different interventions just superimpose concurrent results. On the other hand, it is possible to generate better results, with extra benefits, when proposing adequate combinations capable to join efforts. Mathematical models may act as valuable tools that are able to simulate floods in complex urban watersheds and provide an integrated assessment capability. In this context, mathematical models can evaluate the efficacy of flood control measures sets. In this paper, a mathematical model, based on the flow cell concept, was applied to study the use of a wide range of different flood control measures in the Joana River watershed, located at the northern region of Rio de Janeiro City, Brazil. This model is composed by a hydrodynamic core that works together with a distributed hydrologic model. According to the achieved results, it is possible to notice that distributed detention reservoirs—located at upstream reaches, parks and public squares, and also at urban sites—are very important flood control alternatives. It is also noticed that reforestation of slope areas, although some of which are nowadays occupied by lower income communities, is a desirable alternative. Finally, it must be stressed that even traditional flood control measures, presently avoided in many design situations as they may transfer downstream inundation problems, can be important in an integrated flood control project, if adequately combined with other measures. [ABSTRACT FROM AUTHOR]

Analyzes the results of field observations of the Ipanema Beach ocean outfall in Rio de Janeiro, Brazil. How the dilution and wastefield characteristics were obtained; Comparison of the experimental results with the predictions of some commonly used near field plume mathematical models; Information on field sampling technique.