Human activities over the years, especially the unconventional exploitation of oil sands deposits, downstream on the Athabasca River (AR), might have affected the water quality and ecological integrity of the river basin, thereby presenting a threat to the environment and human health. There have been concerns that the oil sands process-affected waters stored in tailing ponds may be percolating to surface waters as well as underground waters, contaminating neighboring watersheds with a cocktail of chemicals including Polycyclic aromatic hydrocarbons (PAHs). PAHs are present both naturally and from human activities as pollutants in the environment. Forest fires, geologic activities, and oil seeps are examples of natural sources of PAHs in the environment. The major sources of PAHs in the Athabasca region are leaching of oil sands deposits and contamination from oil sands production. On occasions, forest fires contribute PAHs in the area. There has been no comparative data on the exposure of PAHs to fish along the AR and Slave River. I used an integrative monitoring of selected fishes as an indicator to achieve four objectives: i) describe the spatial and seasonal distribution of measurable concentrations of products of biotransformation of polycyclic aromatic hydrocarbons (PBPAH) in bile of fish; ii) determine the levels of parent PAHs in the muscle of fish, and extrapolate the data to estimate potential risk to human consumers, and to identify which species and geographic regions, if any, pose the greatest risk to humans; iii) use patterns of contamination to provide a scientific basis for elucidating the source of contamination; and iv) perform fish health investigation by collecting morphometric health measures and perform a systematic assessment of the occurrence of lesions in the fishes. I sampled whitefish (Coregonus clupeaformis), jackfish/northern pike (Esox luscius), walleye (Sander vitreus), goldeye (Hiodon alosoides) and burbot (Lota lota) from Fort McMurray, Fort McKay, and Fort Chipewyan in Alberta, and from Fort Smith and Fort Resolution on the Slave River in the Northwest Territories. The rationale for selecting fishes included: their abundance along the basin (some have short ranges, e.g., northern pike); their dietary/nutritional and cultural significance to communities in the area; their feeding strategy, such as benthic, supra-benthic, or pelagic, trophic status, and patterns of migration and habits of spawning. I addressed the first objective in Chapter 2, where the total PBPAHs were determined. Concentrations of products of biotransformation of 2 and 3-ringed, 4-ringed, and 5-ringed PAHs were measured using synchronous fluorescence spectroscopy. Spatial and seasonal differences were observed with greater concentrations of PBPAHs in samples of bile of fish collected from Fort McKay as well as greater concentrations of PBPAHs in bile of fish collected during summer compared to those collected in other seasons. Overall, PBPAHs were greater in fishes of lower trophic levels and fishes more closely associated with sediments. In particular, goldeye (Hiodon alosoides), consistently contained greater concentrations of all the PBPAHs studied. In Chapter 3, I achieved the second objective by measuring levels of parent PAHs in muscle of selected fishes and extrapolated the results to determine potential human health risks due to fish consumption. Dorsal muscle of fishes from upstream reaches of the AR close to oil sands extraction and upgrading activities, contained greater concentrations of individual PAHs than concentrations in muscle of fishes from further downstream in the Slave River. Risks posed by PAHs to humans were assessed using a B[a]P equivalents approach. According to the risk assessment results, the average lifetime risk of additional cancers for humans who consumed fish was less than 10-6. In Chapter 4, alkylated PAHs were also measured in fish muscle to achieve the third objective. The general presence of naphthalenes and phenanthrenes and the evaluation of molecular ratios (i.e., LMW/HMW alkyl-PAHs) allowed me to conclude that the major source of pollution is petrogenic, probably due to increases in oil sand activities around Fort McMurray and Fort McKay. I achieved the fourth objective in Chapter 5 by studying the health status and potential effects of industrial development on individuals of economically and culturally significant fishes. A resurgence in condition factor of all species after a low in 2011 was observed. Annual variation was also observed in condition factor and the incidence of anomalies or lesions. Morphometric data demonstrated relatively consistent health among fishes in both the Athabasca and Slave rivers. Analysis of condition factor and somatic indices did not demonstrate consistent differences along the river system. Overall, the health of fish as determined by the metrics employed in this study, does not appear to be adversely affected by the current level of development in the Alberta oil sands region. The data presented in this dissertation make invaluable contribution to the much needed monitoring program in the Athabasca and Slave Rivers. Overall, my findings provide baseline data on fish health, concentrations of parent and alkylated PAHs, and products of biotransformation of PAH in five species of large-bodied fishes consumed by humans in communities in the Lower Athabasca and Slave River basin. These results will be useful for establishing the status and trends and spatial distribution of PAHs during monitoring of the lower Athabasca basin and most importantly, as a valuable reference point before any potential permitted discharges of wastewaters from processing of oil sands to the AR.

Naphthenic acids (NA) are a highly complex mixture of aliphatic carboxylic acids that may contain multiple rings and unsaturated double bonds, and are a subset of the naphthenic acid fraction components (NAFC), which can contain heteroatoms, unsaturations, and aromatic structures. Mono-carboxylated NAs can be classically represented by CnH2n+zO2 where z is a negative integer representing the hydrogen deficiency. NAs and NAFCs are components of the acid extractable organics (AEO) frequently associated with increased toxicity and observed at elevated concentrations in oil sands process waters (OSPW). Numerous chromatographic and mass spectrometry techniques have recently emerged to probe the composition and concentrations of these components. This thesis reports the use of a capillary hollow fiber polydimethylsiloxane (PDMS) membrane mounted on a probe interface that can be immersed directly into an aqueous sample. A methanol acceptor phase passing through the lumen transports analyte to an electrospray ionization source and a triple quadrupole mass spectrometer. This technique, termed condensed phase membrane introduction mass spectrometry (CP-MIMS), allows for rapid screening of m/z profiles and on-line quantification of NAs in complex samples within minutes. This thesis reports parametric studies of several model carboxylic acids and a standard naphthenic acid mixture (Merichem) involving the effect of sample pH on membrane transport and acceptor phase pH on ionization enhancement. Several quantitative strategies are explored including the use of an internal standard in the acceptor phase to correct for ionization suppression and variations in instrument sensitivity, and the use of selected ion monitoring (SIM) experiments to increase analytical sensitivity and potentially target specific NA isomer classes for quantitation. Analytical performance measures such as the linear dynamic range (1-2300 ppb [NA]T as Merichem), sensitivity (~1 ppb [NA]T as Merichem detection limit), precision (~20 %RSD for replicates of a single OSPW) and accuracy are reported. Quantitative results for various OSPW samples in the ppb to ppm range are reported as equivalents of several surrogates, including 1-pyrenebutyric acid (PyBA), Merichem, and a large-volume extract of northern Alberta OSPWs. The variety of quantitation strategies allows results to be compared with several other published methods. CP-MIMS results for three mid-range northern Alberta OSPWs are compared to analysis by Environment Canada with an average -21% bias. Results for five archived OSPWs spanning a wider concentration are compared to data from AXYS Analytical, with an average -49% bias. Applications of CP-MIMS as an in-situ monitor of removal efficiencies of NAs on adsorbents and real-time mass profile changes are also presented, along with some interpretation of the resulting high-resolution kinetic data to obtain decay constants. Using the targeted SIM method, adsorption decay can be followed in real-time for various isomer classes within the Merichem mixture, and kinetic data extracted to obtain decay constants for each. CP-MIMS is also used to characterize adsorption behavior for two activated biochars, including % removals for various loadings of each when added to stirred Merichem solutions. Preliminary multi-loading experiments are conducted with one biochar, and the ability of CP-MIMS to characterize adsorbent behavior by constructing adsorption isotherm plots is demonstrated. / Graduate

Soil improvement methods are used to minimize the consequences of liquefaction by changing the characteristics and/or response of a liquefiable soil deposit. When considering sites with previous development, the options for soil improvement are limited. Traditional methods, such as compaction and vibratory techniques, are difficult to employ because of adverse effects on adjacent structures. One potential method for soil improvement against soil liquefaction in developed sites is accelerated drainage through in situ vertical drains. Vertical drains expedite the dissipation of excess pore water pressures by reducing the length of the pore water drainage path. For more than thirty years, vertical gravel drains or stone columns have been employed to ensure the excess pore water pressure ratio remains below a prescribed maximum value. In recent years, the use of prefabricated vertical drains (PVDs) has increased because the drains can be installed with less site disruption than with traditional soil improvement methods. To date, little-to-no field or experimental verification is available regarding the seismic performance of sites treated with PVDs. The effectiveness of PVDs for liquefaction remediation was evaluated via small-scale centrifuge testing and full-scale field testing. A small-scale centrifuge test was performed on an untreated soil deposit and on a soil deposit treated with small-scale vertical drains. Compared to the untreated condition, the presence of the small-scale vertical drains provided numerous benefits including smaller magnitudes of excess pore water pressure generation and buildup, smaller induced cyclic shear strains, reduced times for pore pressure dissipation, and smaller permanent horizontal and vertical displacements. In addition, full-scale in situ field experiments were performed in an untreated soil deposit and in a soil deposit treated with full-scale PVDs using a vibrating mandrel as the dynamic source. In the untreated test area, the maximum induced excess pore pressure ratio reached about 0.95. In the treated test area, the vibratory installation of the first few drains generated significant excess pore pressures; however, significant excess pore pressures were not generated during the vibratory installation of additional drains because of the presence of the adjacent drains. Additionally, the vibratory installation of the drains caused significant settlement and significantly altered the shear wave velocity of the sand. Dynamic shaking after installation of all of the drains induced small accelerations, small cyclic shear strains, and negligible excess pore water pressures in the soil. The results of the field experiment indicate that the prefabricated vertical drains were effective at dissipating excess pore water pressures during shaking and densifying the site. / text

Les polymères hydrosolubles sont utilisés dans diverses industries pour permettre la floculation, soit une séparation solide-liquide de particules présentes en suspension colloïdale. Afin de réduire les impacts environnementaux de l’exploitation des sables bitumineux en Alberta, l’industrie est à la recherche de nouveaux moyens et procédés pour traiter les résidus miniers permettant de séparer les matières solides et de récupérer l’eau. L’objectif des travaux présentés est d’améliorer la floculation, la densification et la déshydratation de ces résidus miniers aqueux par de nouveaux polymères synthétiques. Des homopolymères d’acrylamide de différentes masses molaires ont été synthétisés pour étudier l’influence de la masse molaire sur l’efficacité de floculation. Le taux initial de sédimentation (TIS) est le paramètre qui fut utilisé afin de comparer l’efficacité de floculation des différents polymères. Il a été possible de confirmer l’importance de la masse molaire sur l’efficacité de floculation et de déterminer une masse molaire minimale d’environ 6 MDa pour des polyacrylamides, afin d’obtenir l’efficacité de floculation maximale de suspensions colloïdales principalement composées de kaolin. Afin d’étudier l’effet des charges sur l’efficacité de floculation, des polymères anioniques et cationiques ont été synthétisés. Une série de copolymères d’acrylamide et d’acide acrylique ont été synthétisés comme polymères anioniques et deux séries de copolymères ont été synthétisés comme polymères cationiques, soit des copolymères d’acrylamide et de chlorure de diallyldiméthylammonium et des copolymères de 4-vinyl pyridine et de 1-méthyl-4-vinyl pyridinium. Il a été démontré que les charges anioniques des polymères avaient peu d’influence sur l’efficacité de floculation et que leur comportement en présence de sels était différent de ce que prévoyait la littérature. Il a aussi été démontré que les charges cationiques des polymères n’améliorent pas l’efficacité de floculation. Par la suite, des séries de copolymères amphiphiles, avec des monomères d’acrylamide, de N-alkylacrylamides et d’acrylonitrile, ont été synthétisés, pour étudier l’effet du caractère amphiphile sur la déshydratation des résidus miniers. Le pourcentage de déshydratation nette est le paramètre qui fut utilisé afin de comparer l’efficacité de déshydratation des différents polymères. Il a été possible de développer des copolymères amphiphiles qui améliorent l’efficacité de déshydratation par rapport à des homopolymères d’acrylamide. Il ne fut pas possible de déterminer une tendance entre la balance hydrophile/hydrophobe des copolymères amphiphiles et l’efficacité de déshydratation. / Water soluble polymers are extensively used in industry to achieve solid-liquid separations of particles in colloidal suspensions. In a way to reduce the environmental footprint of the mining exploitation, the oil sands industry is searching for new methods to treat tailings resulting from the extraction processes, by separating the solids and recycling the water. The objective of this work is to improve the flocculation and dewatering efficiency of the water-based tailings through the use of new synthetic polymers. Acrylamide homopolymers of different molecular weights were synthetized to study the effect of molecular weight on flocculation efficiency. Initial settling rate (ISR) was the parameter measured to characterize and compare the flocculation efficiencies. The important effect of polymer molecular weight on the flocculation efficiency was confirmed. The minimum molecular weight of polyacrylamide for optimal flocculation efficiency of kaolin colloidal suspensions has been determined to be around 6.8 MDa. To study the effect of charge on flocculation efficiency, anionic and cationic copolymers were synthetized. Copolymers of acrylamide and acrylic acid have been synthetized to study the effect of anionic charge, whereas copolymers of acrylamide and diallyldimethylammonium chloride and copolymers of 4-vinyl pyridine and 1-methyl-4-vinyl pyridinium have been synthetized to study the effect of cationic charge. Anionic copolymers have shown limited effect on the flocculation efficiency and their behaviour in salt solution was revealed to be different than expected from the literature. Cationic copolymers have shown no improvement in the flocculation efficiency. Amphiphilic copolymers were synthetized with acrylamide, N-alkylacrylamides and acrylonitrile monomers to study the effect of amphiphilicity on the dewatering efficiency of tailings. The net water release parameter was measured to compare the dewatering efficiency of the polymers. Amphiphilic copolymers that improve tailings’ dewatering, compared to polyacrylamide, were developed. Thus far, it was not possible to define a trend between hydrophilic/hydrophobic balance and dewatering efficiency of the copolymers.

Magister Scientiae - MSc / The objectives of this study were: To review and understand flow and transport processes in unsaturated zones. In this study, particular emphasis is placed on understanding mechanisms that cause non-uniform (preferential) flow for two casestudies, namely the Cape Flats sandy environment and the Mpumalanga Highveld fractured rock environment. To evaluate the adequacy of models, in particular MACRO 5.0, in simulating flow and transport in the vadose zone, by making use of two case study sites (Cape Flats and Mpumalanga Highveld). Of particular importance is the evaluation of transfer coefficients to represent fluid and solute exchange between macropores and matrix. To run a sensitivity analysis with MACRO 5.0 in order determine which input model parameters are the most relevant in describing the effects of preferential flow in water and solute transport.

Neste trabalho foram determinadas as concentrações dos radionuclídeos naturais 226Ra, 232Th e 40K em amostras de areias superficiais para 16 localizações ao longo da costa da Grande Vitória, região metropolitana do estado do Espírito Santo, sudeste do Brasil. As áreas de estudo compreendem as praias de Manguinhos e Jacaraípe no município da Serra, Camburi, Praia do Canto e Curva da Jurema no município de Vitória, Praia da Costa e Praia de Itapuã no município de Vila Velha, Praia de Setibão, Setibinha, Praia do Morro, Praia das Castanheiras e Praia da Areia Preta no Município de Guarapari e areia da Reserva Paulo Cesar Vinha também localizada no município de Guarapari. Para cada sítio de estudo, três amostras foram seladas em frascos de 100 ml de polietileno de alta densidade. Após espera de aproximadamente 4 semanas para atingir o equilíbrio secular das séries do 238U e 232Th, as amostras foram medidas por espectrometria gama de alta resolução e o espectro analisado com o software WinnerGamma. A correção da auto-absorção foi realizada para todas as amostras. A concentração do 226Ra foi determinada pela média ponderada das concentrações do 214Pb e 214Bi, a concentração de 232Th pela média ponderada das concentrações dos 228Ac, 212Pb e 212Bi e a concentração de 40K pela sua transição única de 1460 keV. O equivalente em rádio e o índice gama foram obtidos a partir das concentrações de 226Ra, 232Th e 40K. As concentrações de 226Ra variaram de 3 ± 1Bq.kg-1 a 738 ± 38Bq.kg-1, com o maior valor na localidade central da Praia de Camburi. As concentrações de 232Th variaram de 7 ± 3Bq.kg-1 a 7422 ± 526Bq.kg-1, com o maior valor na Praia da Areia Preta. As concentrações de 40K variaram de 14 ± 6Bq.kg-1 a 638 ± 232Bq.kg-1, com o maior valor na Praia da Areia Preta. O cálculo do equivalente em rádio e do índice gama mostrou duas faixas distintas. Na primeira, para a maioria das praias, o equivalente em rádio variou de 15 ± 6Bq.kg-1 a 257 ± 18Bq.kg-1, abaixo do limite inferior de 370Bq.kg-1 recomendado pela OECD como adequado para uso em material de construção e o índice gama externo foi inferior ao limite aceitável de 1 sugerido pelo UNSCEAR. Na segunda, para as praias de Setibinha, Curva da Jurema, Camburi Sul e Camburi Central e Praia da Areia Preta, o equivalente em rádio variou de 820 ± 40Bq.kg-1 até 11200 ± 580Bq.kg-1, excedendo de 2 a 30 vezes o limite mínimo recomendado para aplicação na construção civil e o índice gama superou de 3 até quase 40 vezes o limite sugerido pelo UNSCEAR. / In this work the concentrations of natural radionuclides 226Ra, 232Th and 40K were determined in superficial sand samples for 16 locations throughout the coast of the Great Victory, metropolitan region of the state of Espírito Santo, Southeast of Brazil. The assessed beaches were Manguinhos and Jacaraípe in Serra county, Camburi, Praia do Canto and Curva da Jurema in Vitória county, Praia da Costa and Itapuã in Vila Velha county, Setibão, Setibinha, Praia do Morro, Praia das Castanheiras and Areia Preta in Guarapari county and sand of the Paulo Cesar Vinha Reserve also located in Guarapari county. Three sand samples of each beach were sealed in 100 mL high density polyethylene flasks. After approximately 4 weeks in order to reach secular equilibrium in the 238U and 232Th series, the samples were measured by high resolution gamma spectrometry and the spectra analyzed with the WinnerGamma software. The selfabsorption correction was performed for all samples. The 226Ra concentration was determined from the weighted average concentrations of 214Pb and 214Bi, the 232Th concentration was determined from the weighted average concentrations of 228Ac, 212Pb and 212Bi and the concentration of 40K is determined by its single gamma transition of 1460 keV. The radium equivalent concentration and the external hazard index where obtained from the concentrations of 226Ra, 232Th and 40K. 226Ra concentrations show values varying from 3 ± 1Bq.kg-1 to 738 ± 38Bq.kg-1, with the highest values for the central locality of the Camburi beach. 232Th concentrations show values varying from 7 ± 3Bq.kg-1 to 7422 ± 526Bq.kg-1, with the highest values for Areia Preta beach. 40K concentrations show values varying from 14 ± 6Bq.kg-1 to 638 ± 232Bq.kg-1, with the highest values for Areia Preta beach. Calculation of the radium equivalent and the external hazard index showed two distinct groups. In the first one, for the majority of the beaches, the radium equivalent activities are in the range from 15 ± 6Bq.kg-1 to 257 ± 18Bq.kg-1, below the lower limit of 370Bq.kg-1 recommended by OECD for the safe use of building materials and external hazard index was below the acceptable limit of 1 suggested by UNSCEAR. In the second one, for Setibinha, Curva da Jurema, South and Central locations of Camburi and Areia Preta beaches, the radium equivalent results are in the range from 820 ± 40Bq.kg-1 to 11200 ± 580Bq.kg-1, exceeding 2 to 30 times the recommended minimum value for safe application in the civil construction industry and the external hazard index surpassed almost 3 to 40 times the UNSCEAR suggested limit.

Das mittlere Baruther Urstromtal und Umgebung zwischen Luckenwalde und Golßen (Brandenburg, Deutschland) ist reich an äolischen Bildungen (DE BOER, 1990). Aus einer Kombination der bekannten Dünentypen (Parabel-, Längs-, Quer- und Kupstendünen) wird eine Reihe von 6 Dünenkomplexen abgeleitet. Sie sind aus einem oder mehreren Dünentypen aufgebaut und haben eine unterschiedliche Genese, Unterschiede im Alter und der Alterssfolge sowie eine bestimmte topographische Lage. Die (oberflächig anstehenden) Talsande/Flug(deck)sande, die Alt- und die Jungdünensande werden von Fein- bis Mittelsanden gebildet. In den jeweiligen Vertikalprofilen ist nach dem Körnungsbild eine Dreiteilung zu erkennen: die "liegenden" (Urstromtalterrassen-)Sande, die Altdünensande und die "hangenden" Jungdünensande. Das Liegende der ältesten Binnendünen ähnelt den Terrassensanden sehr. Daher darf angenommen werden, daß die oberen Urstromtalsande eine starke äolische Komponente besitzen. Altersbestimmungen wurden durch relative Positionierung, Feststellungen zur Art der Bodenbildungen, archäologische Funde, Pollenanalysen sowie Karten- und Literaturstudien vorgenommen, ergänzt durch Radiokarbon- (14C-) und Thermolumineszenzdatierungen. Eine methodische Neuerung ist die automatisierte Bearbeitung der Dünnschliffbilder. Mit dem Quantimet-970-Bildverarbeitungssystem wurde die Einregelung der Längsachsen von Quarzkörnern ermittelt. Die Messungen ergaben, dass die (N)NO-(S)SW-, die ONO-WSW- und die SSO-NNW-Richtungen vorherrschen. Es ist zu vermuten, dass die wichtigsten dünenbildenden Winde im Weichselspätglazial und im Holozän aus den westlichen und südlichen Quadranten wehten, wobei Südwestwinde vorgeherrscht haben dürften. Auf Grund der Forschungsergebnisse werden 12 Phasen der Dünenbildung unterschieden. Sie vermitteln ein Bild der äolischen Prozesse und Landschaftsformen, welches mit Daten aus Niedersachsen und West-Polen größtenteils übereinstimmt. / The Central Baruth Ice-Marginal Valley and surroundings between Luckenwalde and Golßen (Brandenburg, Germany) is rich in aeolian deposits and aeolian landscape forms DE BOER (1990). From a combination of the well-known dune forms (longitudinal, transverse, parabolic and hummocky dunes) a series of 6 dune complexes can be identified. These dune complexes are built by one or several dune types and differ in genesis or building sequence, in age or age sequence as well as in topographic position. The (surficial) valley/aeolian sands, the cover sands and the drift sands are mainly composed of fine- to medium-grained fractions. Based on grain-size analysis three units can be distinguished in the studied vertical profiles: the underlying (valley terrace) sands, the cover sands ("Altdünensande") and the overlying drift sands ("Jungdünensande"). The sands of the substratum of the oldest inland dunes are very similar to these dune sands. Therefore it is accepted that the upper parts of the valley sands contain a strong aeolian component. A modernization is the automated method of long axes orientation measurements on elongated quartz grains in thin sections with the Quantimet-970 Image Analyzer. The results showed that the (N)NE-(S)SW-, the ENE-WSW- and the SSE-NNW-directions dominated. It is to be expected that the most important dune building winds during the Weichselian Late Glacial and during the Holocene were winds from the western and southern quadrants, with southwest winds most likely being the most important. Dating was done by means of relative positioning, palaeosols, archaeological finds, pollen analysis, cartographic and literature research as well as by means of the 14C- and thermoluminescence dating methods. Based on the results of this research 12 dune-forming phases have been distinguished. They give an impression of aeolian processes and landscape forms that are in accordance with dates obtained from dunes in Niedersachsen and west Poland.

A adoção de técnicas de melhoramento de solos é prática cada vez mais recorrente em obras geotécnicas, contudo, os critérios de dosagem e parâmetros de previsão do comportamento desses solos parecem não acompanhar a evolução tecnológica das referidas técnicas. O parâmetro de estado para areias (ψ) não consegue representar o comportamento de areias artificialmente cimentadas, por levar em consideração apenas a influência do índice de vazios e do estado de tensões. Propõe-se, neste estudo, instituir o índice porosidade/teor volumétrico de cimento (η/Civ) como um parâmetro de estado para areias artificialmente cimentadas, por ser um critério racional que relaciona a porosidade da mistura compactada com o teor volumétrico de cimento adicionado. A partir da utilização desse parâmetro, é possível calibrar a quantidade de cimento e a energia de compactação utilizada, a fim de proporcionar uma mistura que atenda aos requisitos de projeto e que seja viável de executar em obra com os recursos materiais e financeiros disponíveis. O programa experimental compreendeu a realização de 17 ensaios triaxiais, drenados e não drenados, analisados em conjunto com resultados já obtidos em estudos anteriores. Análises do comportamento tensão-deformação, variação volumétrica-deformação axial, geração de poropressão, trajetórias de tensões drenadas e não drenadas, envoltórias de resistência, comportamento tensão-dilatância, da aplicação da teoria do estado crítico e uma breve análise estatística embasaram a comprovação de que o parâmetro η/Civ é adequado para previsão do comportamento de corpos de prova de areia artificialmente cimentados. / The adoption of soil improvement techniques is becoming more frequent in geotechnical works, however, the dosage criteria and the parameters used to predict the soil behavior do not seem to follow the technological evolution of these techniques. The state parameter for sands (ψ) cannot represent the behavior of artificially cemented sands because it considers only the influence of the void ratio and the stress state. It is proposed to establish the porosity/volumetric content of cement (η/Civ) as a state parameter for artificially cemented sands, since it is a rational criterion which relates the porosity of the compacted mixture to the volumetric content of cement added. By using this parameter, it is possible to calibrate the amount of cement and the compaction energy used in order to provide a mixture that meets the design requirements and that is feasible to perform on site construction with the material and financial resources available there. The experimental program included the realization of 17 triaxial testes, performed in the drained and undrained conditions, analyzed simultaneously with other results obtained from previous studies. Analysis of stress-strain behavior, volumetric variation-axial strain, pore pressure development, drained and non-drained stress paths, resistance envelope, stress-dilatation behavior, the application of the critical state theory, and a brief statistical analysis supported that the η/Civ parameter is suitable for predicting the behavior of artificially cemented sand specimens.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Devido a sua grande extensão latitudinal, a costa brasileira é influenciada por diferentes regimes climáticos e oceanográficos. Adicionalmente, a distribuição da população brasileira é caracterizada por uma alta concentração nas capitais litorâneas. Todos esses fatores levam à construção de inúmeras estruturas de engenharia que podem de alguma forma impactar o transporte de sedimento e consequentemente o balanço sedimentar de algumas praias. Uma das formas mais eficientes de recuperar esse balanço sedimentar é a alimentação artificial de praias, com sedimentos provenientes da plataforma continental com características semelhantes. Os métodos geofísicos acústicos permitem mapear de forma eficiente o fundo e o subfundo marinho para a busca de áreas fontes para a lavra de forma eficiente. O objetivo deste estudo é a identificação de padrões geoacústicos a partir de analises quantitativas e qualitativas, para a caracterização de áreas fontes de areias siliciclásticas compatíveis com sedimentos de praias em erosão na cidade do Rio de Janeiro. O mapeamento foi realizado na plataforma continental interna do Rio de Janeiro, em área adjacente à praia de Itaipuaçu (Maricá, RJ). As análises evidenciaram depósitos, localizados entre 19 e 30 metros, de areias com granulometria, textura e selecionamento em condições ideias para a recomposição de praias do Rio de Janeiro. / The Brazilian coast is afected by different oceanographic characteristics, mainly due to its large latitudinal extention. Additionally, the distribution of the Brazilian population is characterized by a high concentration in the coastal capital. These facts generate a large number of coastal engineering structures that may impact the sediment transport and consequently the sediment balance in some beaches. All these factors impact some sand beaches and the best choice for its mitigation and recovering is the beach nourishment - with sediments from the continental shelf with similar characteristics. However to find a good place for dredging in the shelf, we need to use geophysical methods that allow to map the bottom and sub bottom environments more efficiently. The objective of this study is the identification of geoacoustics patterns, following qualitative and quantitative analyzes, for characterizing source areas of siliciclastic sands in ideal conditions for recovering eroded beaches in Rio de Janeiro. The mapping was done in the shelf in front of Itaipuaçu beach (Maricá, RJ). The quantitative results showed well sorted median sand placers seaward of the closure depth, located between 19 and 30 meters, ideal for Rios beaches recovering.

Neste trabalho foram determinadas as concentrações dos radionuclídeos naturais 226Ra, 232Th e 40K em amostras de areias superficiais para 16 localizações ao longo da costa da Grande Vitória, região metropolitana do estado do Espírito Santo, sudeste do Brasil. As áreas de estudo compreendem as praias de Manguinhos e Jacaraípe no município da Serra, Camburi, Praia do Canto e Curva da Jurema no município de Vitória, Praia da Costa e Praia de Itapuã no município de Vila Velha, Praia de Setibão, Setibinha, Praia do Morro, Praia das Castanheiras e Praia da Areia Preta no Município de Guarapari e areia da Reserva Paulo Cesar Vinha também localizada no município de Guarapari. Para cada sítio de estudo, três amostras foram seladas em frascos de 100 ml de polietileno de alta densidade. Após espera de aproximadamente 4 semanas para atingir o equilíbrio secular das séries do 238U e 232Th, as amostras foram medidas por espectrometria gama de alta resolução e o espectro analisado com o software WinnerGamma. A correção da auto-absorção foi realizada para todas as amostras. A concentração do 226Ra foi determinada pela média ponderada das concentrações do 214Pb e 214Bi, a concentração de 232Th pela média ponderada das concentrações dos 228Ac, 212Pb e 212Bi e a concentração de 40K pela sua transição única de 1460 keV. O equivalente em rádio e o índice gama foram obtidos a partir das concentrações de 226Ra, 232Th e 40K. As concentrações de 226Ra variaram de 3 ± 1Bq.kg-1 a 738 ± 38Bq.kg-1, com o maior valor na localidade central da Praia de Camburi. As concentrações de 232Th variaram de 7 ± 3Bq.kg-1 a 7422 ± 526Bq.kg-1, com o maior valor na Praia da Areia Preta. As concentrações de 40K variaram de 14 ± 6Bq.kg-1 a 638 ± 232Bq.kg-1, com o maior valor na Praia da Areia Preta. O cálculo do equivalente em rádio e do índice gama mostrou duas faixas distintas. Na primeira, para a maioria das praias, o equivalente em rádio variou de 15 ± 6Bq.kg-1 a 257 ± 18Bq.kg-1, abaixo do limite inferior de 370Bq.kg-1 recomendado pela OECD como adequado para uso em material de construção e o índice gama externo foi inferior ao limite aceitável de 1 sugerido pelo UNSCEAR. Na segunda, para as praias de Setibinha, Curva da Jurema, Camburi Sul e Camburi Central e Praia da Areia Preta, o equivalente em rádio variou de 820 ± 40Bq.kg-1 até 11200 ± 580Bq.kg-1, excedendo de 2 a 30 vezes o limite mínimo recomendado para aplicação na construção civil e o índice gama superou de 3 até quase 40 vezes o limite sugerido pelo UNSCEAR. / In this work the concentrations of natural radionuclides 226Ra, 232Th and 40K were determined in superficial sand samples for 16 locations throughout the coast of the Great Victory, metropolitan region of the state of Espírito Santo, Southeast of Brazil. The assessed beaches were Manguinhos and Jacaraípe in Serra county, Camburi, Praia do Canto and Curva da Jurema in Vitória county, Praia da Costa and Itapuã in Vila Velha county, Setibão, Setibinha, Praia do Morro, Praia das Castanheiras and Areia Preta in Guarapari county and sand of the Paulo Cesar Vinha Reserve also located in Guarapari county. Three sand samples of each beach were sealed in 100 mL high density polyethylene flasks. After approximately 4 weeks in order to reach secular equilibrium in the 238U and 232Th series, the samples were measured by high resolution gamma spectrometry and the spectra analyzed with the WinnerGamma software. The selfabsorption correction was performed for all samples. The 226Ra concentration was determined from the weighted average concentrations of 214Pb and 214Bi, the 232Th concentration was determined from the weighted average concentrations of 228Ac, 212Pb and 212Bi and the concentration of 40K is determined by its single gamma transition of 1460 keV. The radium equivalent concentration and the external hazard index where obtained from the concentrations of 226Ra, 232Th and 40K. 226Ra concentrations show values varying from 3 ± 1Bq.kg-1 to 738 ± 38Bq.kg-1, with the highest values for the central locality of the Camburi beach. 232Th concentrations show values varying from 7 ± 3Bq.kg-1 to 7422 ± 526Bq.kg-1, with the highest values for Areia Preta beach. 40K concentrations show values varying from 14 ± 6Bq.kg-1 to 638 ± 232Bq.kg-1, with the highest values for Areia Preta beach. Calculation of the radium equivalent and the external hazard index showed two distinct groups. In the first one, for the majority of the beaches, the radium equivalent activities are in the range from 15 ± 6Bq.kg-1 to 257 ± 18Bq.kg-1, below the lower limit of 370Bq.kg-1 recommended by OECD for the safe use of building materials and external hazard index was below the acceptable limit of 1 suggested by UNSCEAR. In the second one, for Setibinha, Curva da Jurema, South and Central locations of Camburi and Areia Preta beaches, the radium equivalent results are in the range from 820 ± 40Bq.kg-1 to 11200 ± 580Bq.kg-1, exceeding 2 to 30 times the recommended minimum value for safe application in the civil construction industry and the external hazard index surpassed almost 3 to 40 times the UNSCEAR suggested limit.