A tecnologia de pavimento em concreto permeável surgiu como potencial solução para problemas relacionados à drenagem urbana provenientes da diminuição da área permeável de uma metrópole. Desta forma, sua utilização vem crescendo cada vez mais, inclusive no Brasil. Para avaliar o comportamento hidráulico de uma calçada em concreto permeável, o Laboratório de Mecânica dos Pavimentos da Escola Politécnica da Universidade de São Paulo (LMP-EPUSP) desenvolveu duas misturas para a aplicação em duas calçadas em concreto permeável construídas no Campus da Universidade de São Paulo. A primeira estrutura possui dimensões de 1,00 m x 8,65 m, sem manta permeável, ao passo que a segunda estrutura possui 1,50 m x 84,80 m com sua área dividida em 3 trechos que diferem entre si da seguinte forma: primeiro trecho com manta permeável e infiltração de água no solo; segundo trecho com lona impermeável e sistema de drenagem; e terceiro trecho sem manta e com infiltração de água no solo. Além da análise do comportamento hidráulico da mistura, os métodos construtivos adotados foram avaliados, desde a escolha do local até a cura do concreto. Todas as adequações do método de execução da primeira calçada para a segunda são explícitas e justificadas nesse trabalho, tais como a existência da manta permeável, que na primeira calçada não existia e na segunda surge como uma das soluções para se evitar a colmatação por bombeamento, e detalhes na compactação do revestimento, mantendo uma superfície mais regular. Feita a análise do método construtivo, essa pesquisa também apresenta diversos resultados de taxas de infiltração, em cm/s, in loco obtidos através do ensaio baseado na ASTM C-1701, além de mostrar, através de comparações com diversas referências, o grande potencial hidráulico das misturas desenvolvidas. Esses resultados mostram o comportamento hidráulico das misturas com o tempo. Das informações apresentadas, fica evidente a dependência da escolha do local para um bom comportamento hidráulico a longo prazo, além de explicitar o quão a taxa de infiltração diminui com o tempo em um pavimento construído em ambiente pouco suscetível à colmatação proveniente de árvores e em local muito suscetível. Além disso, o estudo mostra que, apesar de pequenas diferenças nos pavimentos, tais como a infiltração ou não de água no solo, e, no caso contrário, a existência de um sistema de drenagem, o comportamento hidráulico é semelhante. A mesma conclusão é obtida comparando-se os ensaios realizados em bordas e centro do pavimento. Todos os resultados mostrados e conclusões tiradas a partir desses mostram o grande potencial drenante do pavimento de concreto permeável, potencializando com a seleção adequada de materiais, local e método construtivo. / Pervious concrete pavement came as a potential solution to problems related to urban drainage, consequence of the decrease of the permeability area of a metropolis. In this way, its use has been increasing all over the world, including Brazil. In order to evaluate the hydraulic behavior of a permeable concrete sidewalk, the Pavement Mechanics Laboratory of the University of São Paulo developed two mixtures. These mixtures were made for an application on two sidewalks in permeable concrete built in the Campus of the University of São Paulo. The first sidewalk has 1.00 m x 8.65 m, without a geotextile, and the second has 1.50 m x 84.80 m, divided into 3 stretches differing from each other as follows: first section with a geotextile and infiltration of water on soil; Second stretch with waterproof tarpaulin and drainage system; And the third stretch has not a geotextile, but count with the infiltration of water on soil. In addition to the analysis of the hydraulic behavior of the mixture, the constructive methods adopted were evaluated, since the choice of the construction site, until the concrete cure. All adaptations of the method of execution of the first sidewalk to the second one are explicit and justified in this work, such as the existence of the geotextile, that in the first sidewalk did not exist and in the second it appears as one of the solutions to avoid the clogging. Another adaptation was the compaction adopted, which is more regular on the second sidewalk. After the analysis of the constructive method, this research also presents several results of infiltration rates, in cm/s, obtained through the test based on ASTM C-1701, besides showing, through comparisons with several references, the great potential Hydraulic of the mixtures applied. These results show the hydraulic behavior of the mixtures over time. From the information presented, the dependence on the choice of site for a good long-term hydraulic behavior is verified, it is also evidente how much the rate of infiltration decreases with time in a pavement built in a site next to trees and another types of vegetation. In addition, this research shows that the little differences in the methods results in little differences in the infiltration rate, but the hydraulic behavior remains similar. The same conclusion is obtained by comparing the tests performed at the edges and center of the pavement. All presented results and conclusions shows the great potential of the mixtures developed by the LMP-USP, which can be enhanced though the suitable materials selection, construction place and constructive method.

A tecnologia de pavimento em concreto permeável surgiu como potencial solução para problemas relacionados à drenagem urbana provenientes da diminuição da área permeável de uma metrópole. Desta forma, sua utilização vem crescendo cada vez mais, inclusive no Brasil. Para avaliar o comportamento hidráulico de uma calçada em concreto permeável, o Laboratório de Mecânica dos Pavimentos da Escola Politécnica da Universidade de São Paulo (LMP-EPUSP) desenvolveu duas misturas para a aplicação em duas calçadas em concreto permeável construídas no Campus da Universidade de São Paulo. A primeira estrutura possui dimensões de 1,00 m x 8,65 m, sem manta permeável, ao passo que a segunda estrutura possui 1,50 m x 84,80 m com sua área dividida em 3 trechos que diferem entre si da seguinte forma: primeiro trecho com manta permeável e infiltração de água no solo; segundo trecho com lona impermeável e sistema de drenagem; e terceiro trecho sem manta e com infiltração de água no solo. Além da análise do comportamento hidráulico da mistura, os métodos construtivos adotados foram avaliados, desde a escolha do local até a cura do concreto. Todas as adequações do método de execução da primeira calçada para a segunda são explícitas e justificadas nesse trabalho, tais como a existência da manta permeável, que na primeira calçada não existia e na segunda surge como uma das soluções para se evitar a colmatação por bombeamento, e detalhes na compactação do revestimento, mantendo uma superfície mais regular. Feita a análise do método construtivo, essa pesquisa também apresenta diversos resultados de taxas de infiltração, em cm/s, in loco obtidos através do ensaio baseado na ASTM C-1701, além de mostrar, através de comparações com diversas referências, o grande potencial hidráulico das misturas desenvolvidas. Esses resultados mostram o comportamento hidráulico das misturas com o tempo. Das informações apresentadas, fica evidente a dependência da escolha do local para um bom comportamento hidráulico a longo prazo, além de explicitar o quão a taxa de infiltração diminui com o tempo em um pavimento construído em ambiente pouco suscetível à colmatação proveniente de árvores e em local muito suscetível. Além disso, o estudo mostra que, apesar de pequenas diferenças nos pavimentos, tais como a infiltração ou não de água no solo, e, no caso contrário, a existência de um sistema de drenagem, o comportamento hidráulico é semelhante. A mesma conclusão é obtida comparando-se os ensaios realizados em bordas e centro do pavimento. Todos os resultados mostrados e conclusões tiradas a partir desses mostram o grande potencial drenante do pavimento de concreto permeável, potencializando com a seleção adequada de materiais, local e método construtivo. / Pervious concrete pavement came as a potential solution to problems related to urban drainage, consequence of the decrease of the permeability area of a metropolis. In this way, its use has been increasing all over the world, including Brazil. In order to evaluate the hydraulic behavior of a permeable concrete sidewalk, the Pavement Mechanics Laboratory of the University of São Paulo developed two mixtures. These mixtures were made for an application on two sidewalks in permeable concrete built in the Campus of the University of São Paulo. The first sidewalk has 1.00 m x 8.65 m, without a geotextile, and the second has 1.50 m x 84.80 m, divided into 3 stretches differing from each other as follows: first section with a geotextile and infiltration of water on soil; Second stretch with waterproof tarpaulin and drainage system; And the third stretch has not a geotextile, but count with the infiltration of water on soil. In addition to the analysis of the hydraulic behavior of the mixture, the constructive methods adopted were evaluated, since the choice of the construction site, until the concrete cure. All adaptations of the method of execution of the first sidewalk to the second one are explicit and justified in this work, such as the existence of the geotextile, that in the first sidewalk did not exist and in the second it appears as one of the solutions to avoid the clogging. Another adaptation was the compaction adopted, which is more regular on the second sidewalk. After the analysis of the constructive method, this research also presents several results of infiltration rates, in cm/s, obtained through the test based on ASTM C-1701, besides showing, through comparisons with several references, the great potential Hydraulic of the mixtures applied. These results show the hydraulic behavior of the mixtures over time. From the information presented, the dependence on the choice of site for a good long-term hydraulic behavior is verified, it is also evidente how much the rate of infiltration decreases with time in a pavement built in a site next to trees and another types of vegetation. In addition, this research shows that the little differences in the methods results in little differences in the infiltration rate, but the hydraulic behavior remains similar. The same conclusion is obtained by comparing the tests performed at the edges and center of the pavement. All presented results and conclusions shows the great potential of the mixtures developed by the LMP-USP, which can be enhanced though the suitable materials selection, construction place and constructive method.

La construction des biosystèmes d’oxydation passive du méthane (BOPM) est une option économique et durable pour réduire les émissions de méthane des sites d’enfouissement de déchets et des effets subséquents du réchauffement climatique. Les BOPM sont constitués de deux couches principales: la couche d'oxydation du méthane (MOL) et la couche de distribution du gaz (GDL). L'oxydation du méthane se produit dans la MOL par les réactions biochimiques des bactéries méthanotrophes, et la GDL est construite sous la MOL pour intercepter et distribuer les émissions fugitives de biogaz à la base de la MOL. Fondamentalement, l'efficacité d'un BOPM est définie en fonction de l'efficacité d'oxydation du méthane dans la MOL. Par conséquent, il est indispensable de fournir des conditions adéquates pour les activités bactériennes des méthanotrophes. En plus des paramètres environnementaux, l'intensité et la distribution du biogaz influencent l'efficacité des BOPM, et ils peuvent rendre le matériau de la MOL - avec une grande capacité d'accueillir les activités bactériennes - inutilisables en termes d'oxydation du méthane sur place. L'effet de barrière capillaire le long de l'interface entre la GDL et la MOL peut provoquer des émissions localisées de méthane, due à la restriction ou la distribution non uniforme de l’écoulement ascendant du biogaz à la base de la MOL. L'objectif principal de cette étude est d'incorporer le comportement hydraulique non saturé des BOPM dans la conception des BOPM, afin d’assurer la facilité et la distribution adéquates de l'écoulement du biogaz à la base de la MOL. Les fonctions de perméabilité à l'air des matériaux utilisés pour construire la MOL des BOPM expérimentaux au site d’enfouissement des déchets de St Nicéphore (Québec, Canada), ainsi que celles d'autres de la littérature technique, ont été étudiés pour évaluer le comportement d'écoulement non saturé du gaz dans les matériaux et pour identifier le seuil de migration sans restriction du gaz. Ce dernier seuil a été introduit en tant que un paramètre de conception avec lequel le critère de conception recommandé ici, c’est à dire la longueur de la migration sans restriction de gaz (LMSG), a été défini. La LMSG est considérée comme la longueur le long de l'interface entre la GDL et la MOL où le biogaz peut migrer à travers la MOL sans restriction. En réalisant des simulations numériques avec SEEP/W, les effets de la pente de l'interface, des paramètres définissant la courbe de rétention d'eau, de la fonction de la conductivité hydraulique du matériau de la MOL sur la valeur de la LMSG (représentant la facilité d'écoulement du biogaz à l'interface) et de la distribution de l'humidité (et par conséquent celle du biogaz) ont été évalués. Selon les résultats des simulations, la conductivité hydraulique saturée et la distribution des tailles de pores du matériau de la MOL sont les paramètres les plus importants sur la distribution de l'humidité le long de l'interface. Ce dernier paramètre influe également sur la valeur du degré de saturation et donc la facilité du biogaz à la base de la MOL. La densité sèche du matériau de MOL est un autre paramètre qui contrôle la facilité d'écoulement ascendant du biogaz. Les limitations principales de la présente étude sont associées au nombre de matériaux de MOL testés et à l'incapacité de SEEP/W de considérer l'évapotranspiration. Toutefois, compte tenu des hypothèses raisonnables dans les simulations et en utilisant les données de la littérature, on a essayé de réduire ces limitations. En utilisant les résultats des expériences et des simulations numériques, des étapes et des considérations de conception pour la sélection du matériau de MOL et de la pente d'interface ont été proposées. En effet,le comportement hydraulique non saturé des matériaux serait intégré dans les nécessités de conception pour un BOPM efficace, de sorte que la capacité maximale possible d'oxydation du méthane du matériau de la MOL soit exploitée. / Abstract : Implementation of passive methane oxidation biosystems (PMOB) is a cost effective and sustainable solution to eliminate the methane emissions of landfills to the atmosphere and ensuing global warming effects. PMOBs consist of two main layers: methane oxidation layer (MOL) and gas distribution layer (GDL). The oxidation of methane occurs in MOL through the biochemical reactions of methanotrophic bacteria, and GDL is constructed beneath the MOL to intercept and distribute the fugitive biogas emissions at the base of MOL. Basically, the efficiency of a PMOB is defined based on the methane oxidation efficiency in MOL. Therefore, it is indispensable to provide adequate conditions for the bacterial activities of methanotrophs. In addition to the environmental parameters, the intensity and the distribution of the biogas reaching the MOL material influence the efficiency of PMOBs, and they may cause the MOL material possessing great capacity to host the bacterial activities to be unserviceable in terms of in field methane oxidation. The capillary barrier effect along the GDL MOL interface may provoke localized surface methane emissions, resulted from the restricted and/or non uniform distribution of upward flow of biogas at the base of MOL. The main focus of present study is to incorporate the unsaturated hydraulic behavior of PMOBs into the design of PMOBs, providing adequate ease and distribution of upward flow of biogas at the base of MOL. The air permeability functions of the materials used to construct the MOL of experimental PMOBs at the St Nicephore landfill (Quebec, Canada), along with other materials from the technical literature, were studied to evaluate the unsaturated gas flow behavior of the materials and to identify the threshold of unrestricted gas migration. This latter threshold was introduced as a design parameter based on which the recommended design criterion herein, i.e. the length of unrestricted gas migration (LUGM), was defined. LUGM is considered as the length along the GDL MOL interface along which biogas can migrate upwards without restriction. Performing sets of numerical simulations in SEEP/W, the effect of slope of interface and the parameters defining the water retention curve and hydraulic conductivity function of MOL material on value of LUGM (representing the ease of upward flow of biogas at the interface) and distribution of moisture (and therefore biogas) along the GDL MOL interface were assessed. The saturated hydraulic conductivity and the pore size distribution of the MOL material were the most influencing parameters in distribution of moisture along the interface. The latter parameter influences also the value of degree of saturation and therefore, the ease of biogas at the base of MOL. Dry density of MOL material is another parameter that controls the ease of upward flow of biogas. The main limitations of the present study are associated with the number of tested MOL materials and the inability of SEEP/W in considering the evapotranspiration. However, considering reasonable assumptions in simulations and using the data from the literature, it was attempted to reduce the limitations. Based on the results of experiments and numerical simulations, some design steps and considerations for selection of the MOL material and the slope of interface were suggested that incorporate the unsaturated hydraulic behavior into the design necessities for an efficient PMOB so that the maximum possible methane oxidation capacity of MOL material is exploited.

Non-overflow flow-through rockfill structures are river engineering elements used to attenuate and delay inflow hydrographs. They represent expedient places to deposit rather enormous quantities of waste rock at mountainous mine sites. Their application has become so common that matters of safety regarding their design have been laid out in Section 8.5 of the Canadian Dam Safety Guidelines (CDA 2007). The research described herein was directed at investigating the different aspects of the hydraulics of these flow-through rockfill structures. In order to assess the potential for an unraveling failure of flow-through rockfill dams, a systematic study of the hydraulic design of these structures was conducted and the non-linear nature of flow through these structures was dealt with using a p-LaPlacian-like partial differential equation. Subsequently, factors of safety against this type of failure are presented for a range of downstream slopes, thus showing the unsafe combinations of embankment slope and particle diameter. Three different index gradients within the toe of such structures were investigated. In this regard, the gradient most suitable for independently computing the height of the point of first flow emergence on the downstream face is examined and a method for independently computing the variation in hydraulic head within that vertical (which allows for the toe of the structure to be isolated) is presented. An additional gradient that allows for the independent estimation of the default tailwater depth is proposed. In order to provide better tools to assess the behavior of these embankments at the toe, laboratory and analytical studies were undertaken. In this regard, the hydraulics associated with the zone of the downstream toe were studied. The depth variation of the seepage-face was computationally modeled, and two approaches for solving the spatially varied flow (SVF) condition problem within the toe region undertaken. The results show that a dual linear variation in depth can be used to good accuracy, without inducing any unrealistic exit gradients in the zone of primary concern with respect to unraveling. It is hoped that these techniques and computational tools provided herein will aid in facilitating the design and assessment of these flow-through rockfill structures.

No description available.