Ronaldo Luis dos Santos Izzo

Retroanálise da estabilidade de um talude rodoviário da região de Curitiba

Apresenta-se neste trabalho a retroanalise de um escorregamento em um talude rodoviario na encosta da rodovia Curitiba – Ponta Grossa (BR 376), km 4040, situado no municipio de Curitiba, Parana. Por ser um corredor de escoamento de alguns dos principais polos de producao agricola e industrial do Estado, mitigar seu risco de bloqueio ou acidentes e de suma importância. O talude localiza-se na regiao de Formacao Guabirotuba e o solo e classificado como silte-arenoso, conforme norma D- 2487 (ASTM, 2011). Atraves do ensaio de cisalhamento direto obteve-se um intercepto de coesao de 13,45 kPa e um ângulo de atrito interno de 25,85o para este solo. Ha no local um escorregamento do tipo rotacional, por isso, determina-se a mais provavel causa do deslizamento, assumindo hipoteses em que este pode ter ocorrido. Um modelo da geometria inicial do talude foi inserido na ferramenta computacional SLOPE-W (GeoStudio, 2007), e juntamente com seus parâmetros caracteristicos, determina-se o fator de seguranca, atraves do metodo de Spencer, resultando em um fator de 2,18 para o talude em estado seco e 1,42 para o talude em estado parcialmente saturado. Atraves da analise, conclui-se que talude encontra-se estavel no ponto de ruptura existente. Para o talude em estado parcialmente saturado, indicase a aplicacao de drenos profundos de 2,5 metros de comprimento, para assim obter o fator de seguranca acima de 1,5, recomendado pela norma NBR 11682 (ABNT, 2002). A primeira hipotese e devido a uma infiltracao localizada no patamar acima, ocasionando um fluxo de agua corrente, abaixando a coesao para 8,62 kPa, chegando no fator de seguranca unitario. Outra hipotese e a de uma lente no local da ruptura, com parâmetros inferiores aos obtidos em laboratorio. Por fim, a ultima hipotese e a de um recalque na regiao do rompimento do talude, ocasionando um trincamento do solo apos periodo de estiagem e resultando no existente rompimento.

Barreira capilar construida com residuo pre-tratado mecanica e biologicamente

The control of rainwater entry into the municipal solid waste landfill during its construction and after its closure is crucial to keep track of leachate generation. This is a factor that may contribute to the increase of costs on treatment and monitoring and to the mechanical instability of the landfill. For this reason, the final cover system of a municipal solid waste landfill is critical for controling the water entering into the landfill. In most cases, the final cover system is made of compacted soil. Often, suitable soil for landfilling is not found in its surroundings, and resources must be expended in transporting the soil to the landfill site. An alternative would be to use a capillary barrier constructed with mechanical and biologically pretreated waste. However, the use of this material to construct capillary barriers has not been studied and several variables involved in the operation of a capillary barrier constructed with municipal solid mechanical and biologically pretreated waste landfill are unknown. The objective of this study was to analyze the parameters involved in the operation of a capillary barrier built exclusively solid waste pre-treated mechanically and biologically. It was observed that the MSW MBT used as a capillary barrier material may function similarly to that constructed with soil, with a good capacity for rain water retention

Waste Mechanics Research Needs: A Perspective from Brazil

In Brazil, solid waste landfills were managed from a sanitary engineering viewpoint, and engineers operating the landfills were generally mechanical or electrical engineers, more concerned with waste collection and transport logistics than in fact with waste disposal and its possible impacts on the environment. It was only after the Bandeirantes landfill accident (see Figure 1) that geotechnical engineers were in fact called to play a more important role in landfill projects and management. It should also be mentioned that in most cases, landfill accidents do not involve people and when they do, they affect lives in areas that do not have the ability to engage the media so that the incident is not news or very quickly forgotten. Figure 2 shows the Bandeirantes landfill in operation years after the accident.

MBT Waste Used as a Capillary Barrier in a Sanitary Landfill

A capillary barrier is an alternative technology for the final cover of sanitary landfills that has been very successfully studied in recent years on several landfills. Its functionality is based on the retention capacity and unsaturated hydraulic conductivity of the materials used. Although a more attractive alternative than the traditional use of geosynthetic materials and clay layers in the construction of the final cover system, a large amount of soil is still required for the capillary barrier, giving rise to the need to find appropriate soils and occupying a large volume in the landfill. A more sustainable solution would be to build the capillary barrier using mechanical biological pre-treated waste (MBT) as building material. This paper presents the results of laboratory tests to evaluate the main factors that influence a capillary barrier built with mechanical biological pre-treated waste.