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Analyse und Konzeption von Messstrategien zur Erfassung der bodenhydraulischen VariabilitätMorgenstern, Yvonne 04 December 2007 (has links)
Die Berücksichtigung der flächenhaften bodenhydraulischen Variabilität gilt bei der Modellierung von Wasser- und Stofftransportprozessen als problematisch. Dies liegt vorrangig an ihrer Erfassung, die kosten- und zeitintensiv ist. Die vorliegende Arbeit untersucht verschiedene Messstrategien, die zur Abbildung der flächenhaften Bodenhydraulik mit wenigen, einfach zu bestimmenden und physikalisch begründeten Bodenparametern führen. Die Vorgehensweise erfolgt mit der Anwendung eines Ähnlichkeitskonzeptes, das die Böden in bodenhydraulisch ähnliche Klassen unterteilt. Innerhalb einer Klasse kann die Variabilität der Retentions- und hydraulischen Leitfähigkeitcharakteristik auf einen freien Parameter (Skalierungsparameter) reduziert werden. Die Analyse der Zusammenhänge zwischen Boden- und Skalierungsparametern führt letztendlich zu den geeigneten Parametern die eine flächenhafte Abbildung möglich machen. Diese Untersuchungen bilden die Grundlage für die weitere Entwicklung eines stochastischen Modellansatzes, der die Variabilität der Bodenhydraulik bei der Modellierung des Bodenwassertransportes im Feldmaßstab berücksichtigen kann. An Hand von drei Datensätzen unterschiedlicher Skalenausbreitung konnte dieses Konzept angewendet werden. Die Ergebnisse zeigen, dass die Beschreibung der hydraulischen Variabilität nur für die vertikale (Profil) nicht aber für die flächenhafte Ausbreitung mit einfachen Bodenparametern möglich ist. Mit einer ersten Modellanwendung konnte gezeigt werden, dass über die Variabilität der Bodenparameter Trockenrohdichte und Tongehalt auch die Variabilität der Bodenhydraulik und damit die Berechnung des Bodenfeuchteverlaufs am Standort darstellbar ist. / The consideration of the spatial variability of the unsaturated soil hydraulic characteristics still remains an unsolved problem in the modelling of the water and matter transport in the vadose zone. This can be mainly explained by the rather cumbersome measurement of this variability, which is both, time-consuming and cost-intensive. The presented thesis analyses various measurement strategies which aim at the description of the soil-hydraulic heterogeneity by a small number of proxy-parameters, which should be easily measurable and still have a soil-physical meaning. The developed approach uses a similarity concept, which groups soils into similar soil hydraulic classes. Within a class, the variability of the retention and hydraulic conductivity curves can be explained by a single parameter (scaling parameter). The analysis of the correlation between the soil parameters and the scaling parameters can eventually indicate which soil parameters can be used for describing the soil hydraulic variability in a given area. This investigation forms the basis for the further development of a stochastic model, which can integrate the soil-hydraulic variability in the modelling of the soil water transport. Three data sets, all covering different scales, were subsequently used in the application of the developed concept. The results show that depth development of the soil-hydraulic variability in a soil profile can be explained by a single soil parameter. Contrarily, the explanation of the horizontal variability of the soil-hydraulic properties was not possible with the given data sets. First model applications for a soil profile showed that including the variability of the soil parameters bulk density and clay fraction in the water transport simulations could describe the variability of the soil-hydraulic variability and thus, the dynamics of the soil water content at the investigated profile.
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Effects of Thermal Gradient and Fines Content on Frost Heave of an Alaska Base MaterialHomewood, Adam Ray 08 October 2010 (has links) (PDF)
The objective of this research was to investigate the effects of thermal gradient and fines content and the interaction between these two factors on the frost heave characteristics of a typical Alaska base material. The laboratory frost heave testing involved one type of aggregate base material, three thermal gradients, and three fines contents in a full-factorial experimental design with two replicates. The aggregate was classified in the American Association of State Highway and Transportation Officials soil classification system as A-1-a; the thermal gradients were 0.15, 0.30, and 0.45 ºC/cm; and the fines contents were 6, 8, and 10 percent. After frost heave testing, a stepwise regression analysis was performed to identify significant independent variables for each of nine separate dependent variables, including frost heave, heave-uptake ratio, steady-state frost heave rate, gravimetric water ingress, and gravimetric water content in each of the five individual lifts tested following frost heave testing. Soil suction, specific gravity, salinity, and hydraulic conductivity testing were also performed on samples prepared at each of the three fines contents to support numerical modeling of the frost heave test results using the computer program ICE-1. The results of the stepwise regression analysis indicate that thermal gradient is a significant predictor of six of the nine dependent variables and that the square of thermal gradient is a significant predictor of five of these six dependent variables. As the thermal gradient increased, the samples experienced decreasing amounts of water ingress and frost heave. However, the data show that neither fines content nor the square of fines content is a significant predictor of any of the dependent variables. Thus, although previous research has shown that higher fines contents are generally associated with greater susceptibility to frost heave, this effect is not manifest in the comparatively small increases in fines contents evaluated in this research. The interaction between thermal gradient and fines content is a significant predictor of only one independent variable. Differences between the modeled and measured frost heave values ranged from 0.01 to 0.92 cm, with the larger differences typically associated with the lowest thermal gradient and the lowest fines content.
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Swelling, Thermal, and Hydraulic Properties of a Bentonite-Sand Barrier in a Deep Geological Repository for Radioactive Wastes: Effect of Groundwater Chemistry, Temperature and Physical FactorsAlzamel, Mohammed 11 August 2022 (has links)
Electricity generation at nuclear power plants produces a large amount of high-level radioactive waste (HLW) every year, which has long-term detrimental effects on humans and the environment. Other applications of nuclear technology (e.g., medicine, research, nuclear weapons, industry) also produce radioactive waste (e.g., low-level radioactive waste, LLW, Intermediate-level waste, ILW). The potential of deep geological repositories (DGRs) as an option for disposal of radioactive waste (HLW, ILW, LLW) has been examined in several countries, including Bulgaria, Canada, China, Finland, France, Germany, India, Japan, Russia, Spain, Sweden, Switzerland, Ukraine and the United Kingdom and are still under discussion. In Ontario, Canada, DGRs with a multi-barrier system comprised of a sedimentary rock formation (i.e., a natural barrier) and an engineered barrier system (EBS) are currently under consideration. An EBS consists of various components, such as waste containers, buffer, backfill, and tunnel sealing materials, intended to prevent the release of radionuclides. Several engineered barrier materials, including a mixture of bentonite and sand, are currently being considered for use in DGRs for nuclear waste in Ontario. Bentonite has some advantageous physical and chemical properties, such as low permeability, high plasticity, and high swelling potential, which provide it with a good sealing ability and thus make it an effective barrier. However, interaction between the compacted bentonite–sand mixture and underground water chemistry fluids (chemical factor) in the DGR could significantly alter the favourable properties of bentonite (e.g., swelling potential), thus influencing its performance when used in an EBS and eventually jeopardizing the overall safety of DGRs. In addition, other parameters, such as the clay content, initial dry density and moisture content of the compacted barrier (physical factors), as well as the presence of salts in groundwater may affect the physical and physiochemical properties of barrier materials. Moreover, during the lifetime of a DGR for used spent fuel, the bentonite–based barrier material will not only be exposed to a broad range of groundwaters with different chemical compositions, but also to high temperatures (heat generated by the nuclear wastes) (thermal factor). Thus, the interaction between the compacted bentonite–sand mixture, the surrounding groundwater and the heat from the nuclear waste material could jeopardize the favourable properties of the bentonite-based (bentonite-sand) barrier material. Properties of a bentonite-sand barrier is an important characteristic to study while designing and constructing an EBS for a DGR. Thus, to understand and assess the operations of DGRs in Ontario, comprehensive studies must be performed on engineering properties like swelling behaviour, permeability, and thermal conductivity. The goal of this research study is to experimentally investigate the physical, chemical and thermal factors that influencing the engineering properties of a barrier material made up of bentonite-sand composite used in DGRs for nuclear waste in Ontario. Compacted samples are subjected to one-dimensional free swell test to understand the swelling behaviour of the material. Hydraulic conductivity was investigated using a flexible wall permeability test. Thermal conductivity and diffusivity were tested using Decangon KD2 Pro with TR-1 and and KS-1 sensors. The specimens contain different bentonite–sand mixture ratios (20:80, 30:70, 50:50, and 70:30 dry mass), and they are
tested under conditions with differing bentonite content, dry density, groundwater chemistry, and temperature. Additional tests were conducted to investigate the microstructure of the specimens. These tests include X-ray diffraction (XRD) analysis, mercury intrusion porosimetry (MIP), and thermogravimetric analyses (TG/DTG). The results reveal that the time and strain required to achieve maximum swelling of compacted bentonite–sand specimens increase with the increase of initial dry density. The simulated saline solutions of Guelph and Trenton groundwater are found to suppress the swelling of the bentonite–sand specimens. This in turn leads to the increase of hydraulic conductivity and decrease of thermal properties of the barrier material. However, the impact of the salinity is significantly reduced by increasing the dry densities and sand content of the compacted material. Moreover, the coupled effect of salinity and temperature decreases the swelling potential of the bentonite-sand mixture. Also, some transformation of Na-montmorillonite into Ca-Montmorillonite was observed. The results also indicate that some montmorillonites might have been transformed into illites, thereby further decreasing the swelling potential of the bentonite-based barrier.
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[pt] ENSAIOS DE PERMEABILIDADE DE LABORATÓRIO NA AREIA DA PRAIA DE IPANEMA E EM UMA AMOSTRA DE MICROESFERAS DE VIDRO / [en] LABORATORY PERMEABILITY TESTS ON IPANEMA BEACH SAND AND ON A SAMPLE OF GLASS MICROSPHERESBEATRIZ RODRIGUES SOARES 23 May 2022 (has links)
[pt] Esta pesquisa teve como principal objetivo contribuir para a avaliação da
influência da forma dos grãos na condutividade hidráulica (k) de areias. Para tanto,
ensaios de laboratório foram realizados em uma amostra da areia da Praia de
Ipanema (D10 = 0,28 mm, D30 = 0,34 mm, D50 = 0,41 mm, D60 = 0,45 mm, CNU =
1,61 e CC = 0,92), constituída por grãos subarredondados a arredondados
(esfericidade = 0,65 e arredondamento = 0,70), e em uma amostra de
microesferas de vidro, tipo Drop-On II A (esfericidade = 0,95 e arredondamento =
0,95), preparada com granulometria igual à da areia. O programa experimental
envolveu: (a) limpeza e tratamento das amostras; (b) análises microscópicas para
avaliação da forma dos grãos; (c) ensaios de granulometria por peneiramento; (d)
reconstituição granulométrica da amostra de microesferas de vidro; (e) densidade
relativa (Gs) das microesferas de vidro; (f) ensaios de índices de vazios máximo,
pelo método B da ABNT (2020), e ensaios de índices de vazios mínimo e
intermediários, pela método MSP de Miura e Toki (1982); e (g) ensaios de
permeabilidade sob carga hidráulica constante em permeâmetro de parede rígida
e em permeâmetro de parede flexível. Para ambas as amostras, verificou-se
experimentalmente a validade da relação linear entre a condutividade hidráulica
(k) e e(3)/(1+e), sendo e o índice de vazios, em consonância com as formulações
teóricas propostas por Kozeny-Carman (1927) e por Taylor (1948). Para um dado
índice de vazios, constatou-se que a condutividade hidráulica da amostra de
microesferas de vidro é maior do que a da amostra da areia da Praia de Ipanema. / [en] The main objective of this research was to contribute to the evaluation of
the influence of the grain shape on the hydraulic conductivity (k) of sands. For that,
laboratory tests were carried out on a sample from Ipanema Beach sand (D10 =
0.28 mm, D30 = 0.34 mm, D50 = 0.41 mm, D60 = 0.45 mm, CNU = 1.61 e CC = 0.92),
composed by sub-rounded to rounded grains (sphericity = 0.65 and roundness =
0.70), and on a sample of glass microspheres, Drop-On II A type (sphericity = 0.95
and roundness = 0.95), prepared with the same grain size distribution of the sand.
The experimental program comprised: (a) cleaning and processing of the samples;
(b) microscopic analysis to evaluate the grain shape; (c) grain-size analysis by
sieving; (d) reconstitution of the grain-size distribution of the glass microspheres
sample; (e) glass microspheres specific gravity (Gs); (f) maximum void ratio tests,
by method B of ABNT (2020), and minimum and intermediate void ratio tests, by
MSP method of Miura and Toki (1982); and (g) constant head permeability tests in
rigid-wall permeameter and in flexible-wall permeameter. For both samples, it was
experimentally verified the validity of the linear relationship between the hydraulic
conductivity (k) and e (3)/(1+e), being e the void ratio, in agreement with the
theoretical formulations proposed by Kozeny-Carman (1927) and by Taylor (1948).
For a given void ratio, it was observed that the hydraulic conductivity of the glass
microsphere sample is higher than that of the sample from Ipanema Beach sand.
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Characterization and Bioremediation Viability of Polycyclic Aromatic Hydrocarbon Contamination in the Banks of the Mahoning RiverBuffone, Steven A. 16 September 2015 (has links)
No description available.
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Soilless Substrate Hydrology and Subsequent Impacts on Plant-Water Relations of Containerized CropsFields, Jeb Stuart 03 February 2017 (has links)
Freshwater is a finite resource that is rapidly becoming more scrutinized in agricultural consumption. Specialty crop producers, especially ornamental crop producers, must continually improve production sustainability, with regards to water resource management, in order to continue to stay economically viable. Soilless substrates were initially developed to have increased porosity and relatively low water holding capacity to ensure container crops would not remain overhydrated after irrigations or rain events. As a result, substrates were selected that are now considered to be in efficient in regards to water resource management. Therefore, to provide growers with additional means to improve production sustainability, soilless substrate hydrology needs be innovated to provide increased water availability while continuing to provide ample air filled porosity to ensure productive and efficient water interactions. Historically, soilless substrates have been characterized using "static" physical properties (i.e. maximum water holding capacity and minimum air-filled porosity). The research herein involves integrating dynamic soilless substrate hydraulic properties to understand how substrate hydrology can be manipulated to design sustainable substrates. This task involved adapting new technologies to analyze hydrological properties of peat and pine bark substrates by employing evaporative moisture characteristic measurements, which were originally designed for mineral soils, for soilless substrate analyses. Utilizing these evaporative measurements provide more accurate measures of substrate water potentials between -10 and -800 hPa than traditional pressure plate measurements. Soilless substrates were engineered, utilizing only three common substrate components [stabilized pine bark (Pinus taedea L.), Sphagnum peatmoss, and coconut coir fiber], via particle fractionation and fibrous additions. The engineering process yielded substrates with increased unsaturated hydraulic conductivity, pore connectivity, and more uniform pore size distributions. These substrates were tested in a greenhouse with irrigation systems designed to hold substrates at (-100 to -300 hPa) or approaching (-50 to -100 hPa) water potentials associated with drought stress. Substrate-water dynamics were monitored, as were plant morphology and drought stress indicators. It was determined that increased substrate unsaturated hydraulic conductivity within the production water potentials, allowed for increased crop growth, reduction in drought stress indicators, while producing marketable plants. Furthermore, individual plants were produced using as low as 5.3 L per plant. Increased production range substrate hydraulic conductivity was able to maintain necessary levels of air-filled porosity due to reduced irrigation volumes, while providing water for plants when needed. The substrates were able to conduct water from throughout the container volume to the plant roots for uptake when roots reduced substrate water potential. Furthermore, increased substrate hydraulic conductivity allowed plants within the substrate to continue absorbing water at much lower water potentials than those in unaltered (control) pine bark. Finally, HYDRUS models were utilized to simulate water flux through containerized substrates. These models allowed for better understanding of how individual hydraulic properties influence substrate water flux, and provided insight towards proportions of inaccessible pores, which do not maintain sufficient levels of available water. With the models, researchers will be able to simulate new substrates, and utilize model predictions to provide insight toward new substrates prior to implementing production tests. It has been determined, that increasing substrate hydraulic conductivity, which can be done with just commonly used components, water requirements for production can be reduced, to produce crops with minimal wasted water resources. Concluding, that re-engineering substrate hydrology can ameliorate production sustainability and decrease environmental impact. / Ph. D.
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Analýza vzájemného vztahu dvou metod terénního měření infiltrace vody do půdy / Analysis of the mutual relationship between two methods of field measurement of water infiltration into the soilLarišová, Lucie January 2012 (has links)
This thesis deals with the theoretical description of the infiltration process and field measurements of infiltration in the cadastral territory of Bohaté Málkovice. The research work carried out in 2011 in an experimental area on Haplic Chernozem/FAO, medium-heavy loam soil. The experimental area was divided into two parts, the topsoil layer on these surfaces was processed by both classic and minimization technologies. The plots were sown by spring barley. The applied measurements of water infiltration into the soil were two-cylinder method and MiniDisc. Within the vicinity of the infiltration experiments with intact soil were collected samples for laboratory determination of saturated hydraulic conductivity. From the field measurements and laboratory experiments were determined values of hydraulic conductivity (saturated and unsaturated), and other infiltration characteristics, the cumulative infiltration and infiltration rate. To evaluate the infiltration of the heats was used three-paramether Philp type equation that provides a good estimate of saturated hydraulic conductivity. For the evaluation of the MiniDisc there was used the Zangova method that provides the unsaturated hydraulic conductivity. The laboratory evaluation of the saturated hydraulic conductivity was compared with the estimated values obtained from the field measurements. The values of the saturated hydraulic conductivity from the laboratory measurements are closely comparable with estimates obtained from the steady infiltration rates from the field experiments. The research results also showed that medium-heavy loam soil, when being processed by minimization including modification of the soil surface by digging, have a positive effect on the infiltration of water into the soil. This fact leads to a higher protection plants in the vegetative period and improvement of the retention and storage capacity of soil.
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Incorporação de Resíduos Urbanos e as Propriedades Físico-Hídricas de um Latossolo Vermelho Amarelo. / Urban Residues Incorporation and Soil Physico-Hidric Properties of a Red Yellow LatosolMarciano, Cláudio Roberto 14 May 1999 (has links)
Conduziu-se durante dois anos, em um Latossolo Vermelho Amarelo, em Piracicaba-SP (22o4100" S; 47o3900" O; 554 m de altitude), um experimento com a cultura da cana-de-açúcar. Foram utilizados 9 tratamentos com 4 repetições, implantados num delineamento em blocos ao acaso. Os tratamentos foram: tr1 - adubação mineral + calagem; tr2, tr3; tr4 e tr5 - doses de lodo de esgoto (respectivamente, 0; 33; 66 e 99 Mg ha-1, no primeiro ano, e 0; 37; 74 e 112 Mg ha-1, no segundo ano); tr6, tr7; tr8 e tr9 - doses de composto de lixo (respectivamente, 0; 20; 40 e 60 Mg ha-1, no primeiro ano, e 0; 24; 48 e 72 Mg ha-1, no segundo ano). Os resíduos foram aplicados manualmente na superfície do solo e incorporados com enxada rotativa, no primeiro ano em área total e no segundo apenas na entrelinha. Foram determinados, em cada parcela, os seguintes parâmetros do solo: composição granulométrica (amostras coletadas antes da implantação do experimento); o conteúdo de carbono orgânico (amostras coletadas em 15 datas durante os dois anos); conteúdo de argila dispersa em água, densidade e porosidade total (amostras coletadas ao final do primeiro e do segundo ano do ciclo da cultura); curva de retenção de água, condutividade hidráulica do solo saturado e condutividade hidráulica relativa (amostras coletadas ao final do primeiro ano do ciclo da cultura); e condutividade hidráulica do solo saturado e não saturado (determinada no campo ao final de dois anos do ciclo da cultura, utilizando o infiltrômetro de tensão). Os resultados obtidos mostraram que houve redução da densidade do solo e aumento da porosidade total com o aumento das doses dos resíduos, para a camada de 0 a 0,15 m de profundidade, no segundo ano de aplicação. Nas parcelas que receberam aplicações de ambos os resíduos, houve aumento da condutividade hidráulica do solo próximo à saturação e redução à medida que o solo se afasta da saturação, para a faixa de potencial mátrico estudada (0 a 1 kPa). O decaimento da condutividade hidráulica relativa, a partir da saturação, foi inicialmente mais acentuado nas parcelas que receberam aplicações de ambos os resíduos, quando comparadas às que não receberam resíduos. Verificou-se também, através de análises de regressão múltipla, que diferenças na retenção de água e no conteúdo de argila dispersa em água, que pela análise de variância convencional seriam atribuídas exclusivamente aos tratamentos, de fato eram parcial ou totalmente devidas a variações não casuais na composição granulométrica do solo. Pelos resultados pôde-se concluir que a aplicação de resíduos urbanos ao solo leva a modificações de propriedades como a densidade e porosidade total do solo, a condutividade hidráulica do solo saturado e a condutividade hidráulica do solo não saturado. Pôde-se concluir também que a casualização dos tratamentos na área experimental não garante a ausência de covariação entre os tratamentos e outras variáveis independentes, as quais podem interferir nas propriedades de interesse (variáveis dependentes) e, conseqüentemente, na eficiência da análise de variância feita de maneira convencional, sendo recomendado a realização de um "ensaio em branco" para verificar a eficiência desta casualização. / An experiment was carried out during two years on a Red Yellow Latosol cropped with sugar-cane, located in the country of Piracicaba-SP (22o4100" S; 47o3900" W; 554 m high). Nine treatments with 4 replications were used in a random-block experimental design. The treatments were: tr1 - mineral fertilization + CaCO3; tr2, tr3; tr4 and tr5 - levels of sewage sludge (respectively, 0; 33; 66 and 99 Mg ha-1, in the first year, and 0; 37; 74 and 112 Mg ha-1, in the second year); tr6, tr7; tr8 and tr9 - levels of composed of garbage (respectively, 0; 20; 40 and 60 Mg ha-1, in the first year, and 0; 24; 48 and 72 Mg ha-1, in the second year). The residues were manually applied on the soil surface and incorporated with a rotative plough. In the first year, the incorporation was done on the total area; in the second year only in inter-rows. The following soil parameters were determinated in each plot: particle size distribution (samples collected before the installation of the experiment); organic carbon content (15 samplings along the two years); natural clay content, soil bulk density and total soil porosity (sampling at the end of the first and second years of the growing cycle); water retention curves, saturated hydraulic conductivity and relative unsaturated hydraulic conductivity (samples collected at the end of the first year of the growing cycle); and saturated and unsaturated hydraulic conductivity (determined in situ at the end of the first and second years of the growing cycle, using tension infiltrometer). Results show a decrease the soil bulk density and increase of total porosity as the levels of residue application increased, for the 0 to 0.15 m soil layer, in the second year of application. On the plots that received applications of both residues, there was increase of the hydraulic conductivity near the soil saturation and decrease for the 0 to 1 kPa matric potential range. The decline of the relative hydraulic conductivity starting from the saturation, was initially more accentuated in the plots that received applications of both residues as compared with the ones that did not. It was also verified, through analyses of multiple regression, that differences in the water retention and in the natural clay content, that they would be attributed exclusively to the treatments by the conventional variance analysis, they were partially or totally owed to non casual variations in the particle size distribution of the soil. It could be concluded that the soil application of urban residues causes modifications of soil physical properties as saturated and unsaturated soil hydraulic conductivity. It could also be concluded that the randomization of the treatments in the experimental area does not guarantee the covariance absence between the treatments and other independent variables, which can interfere in the properties of interest (dependent variables) and, consequently, in the efficiency of the variance analysis done in a conventional way.
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Análise da variabilidade espacial da precipitação e parâmetros hidrológicos em bacia experimental: estudo da transformação da chuva em uma pequena bacia hidrográfica urbana / Analysis of the spatial variability of precipitation and of hydrologic parameters in experimental basin: study of rainfall-runoff transformation in a small urban hydrographic basinSilva, Karla de Andrade e 11 April 2003 (has links)
A primeira parte deste trabalho consistiu na instalação de pluviógrafos e linígrafos e levantamento de eventos hidrológicos com a obtenção de dados da distribuição espacial de precipitações observadas e hidrogramas resultantes. Experimentos de infiltração de água no solo foram realizados a partir de infiltrômetro de disco a fim de caracterizar a variabilidade espacial da condutividade hidráulica na bacia, obtendo-se dois conjuntos de dados que mostraram ser lognormalmente distribuídos com médias iguais a 15,8 mm/h e 5,47 mm/h. Estudo teórico foi conduzido na segunda parte do trabalho compreendendo o desenvolvimento de modelo hidrológico. A concepção do modelo parte da premissa de que toda a área da bacia possa ser representada por células derivadas de um modelo numérico de terreno (MNT), especificando-se em cada célula o equacionamento hidráulico-hidrológico. As heterogeneidades do solo e da precipitação foram estudadas através de simulação do modelo considerando-se distribuições espaciais diferentes para a condutividade hidráulica saturada e eventos de chuva. Os resultados mostraram que as diferenças entre as vazões de pico podem ser maiores que 100% , considerando-se graus de resolução máximo e mínimo quanto à precipitação, e reafirmaram o consenso de que o conhecimento da distribuição espacial da chuva é fundamental na calibração de modelos hidrológicos distribuídos. / In first part of this work consists on the installation of pluviographic, water-height graphs and surveying of hydrological events with obtained data from spatial distribution of precipitation observed and resultant hydrograms. Experiments of water infiltration in the soil were done by an infiltrometer disc to characterize the spatial variability of hydraulic conductivity and the losses of infiltration in the basin obtaining two sets of data that showed to be lognormally distributed in average equal to 15.8 mm/h and 5.47 mm/h. A theoric study was conduced in the second part of work comprehending the development of hydrologic model distributed. The conception of the model proceed from the premise that allbasin area can be represented by cells derived from a Digital Terrain Model (DTM) specifying in each cell the hydraulic equation - hydrologic. The soil heterogeneity and the precipitation were studied by model simulation considering spatial distributions different to the hydraulic conductivity satured of the soil and to pluvial events. The results pointed out the differences among peak outflow can be more than 100% considering minimum and maximumresolution degrees as the precipitation and affirmed the consensus that the acquaintance of the pluvial spatial distribution is fundamental in the adjustment of hydrologic models distributed.
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Investigação do comportamento geotécnico de misturas de solo arenoso com lodo da Estação de Tratamento de Água Cubatão. / Research on the geotechnical behavior of mixtures of sandy soil with sludge from Cubatão water treatment plant.Tejeda Montalvan, Edy Lenin 26 September 2016 (has links)
O descarte do lodo de ETA em corpos de água, como rios, tem sido ainda uma prática comum no Brasil. Alternativas frequentes de destinação têm sido a disposição do lodo em aterros sanitários ou industriais e na rede de esgoto. Porém, os padrões ambientais cada vez mais rígidos têm levado à procura de soluções mais econômicas e benéficas, com o aproveitamento do lodo de ETA como material para diversos usos. Uma das opções promissoras é a utilização do lodo de ETA misturado a solos naturais em obras geotécnicas, como revestimento de fundo e cobertura final de aterros sanitários e industriais, e na construção de aterros em geral. Nessa perspectiva, foram estudadas as propriedades geotécnicas de misturas de um solo laterítico arenoso com um lodo de ETA em três proporções solo:lodo (3:1, 4:1, e 5:1) em massa úmida. Foi realizada a caracterização química e mineralógica do solo e do lodo por meio de ensaios de difração de raios X, fluorescência de raios X, microscopia eletrônica de varredura, determinação de perda ao fogo, pH, capacidade de troca catiônica, soma de bases trocáveis, carbono orgânico, matéria orgânica, entre outros. Foram determinados a curva granulométrica, a massa específica dos grãos e os limites de consistência do solo, do lodo e das misturas. Ensaios de adensamento, permeabilidade e compressão triaxial foram realizados em corpos de prova compactados do solo e das misturas. A caracterização geotécnica das misturas mostrou que a adição de lodo não altera significativamente a granulometria, a massa específica dos grãos e os limites de consistência do solo. Por outro lado, a secagem prévia ao ar das misturas alterou os parâmetros de compactação: a massa específica seca máxima aumentou e o teor de umidade ótimo diminuiu com a redução do teor de umidade inicial no ensaio de compactação. Os índices de compressão das misturas apresentaram-se maiores que o do solo, enquanto as condutividades hidráulicas das misturas foram menores que a do solo. O ângulo de atrito efetivo das misturas apresentou aumento e a coesão efetiva diminuição a medida que a proporção de lodo acrescentado ao solo aumentou. As características e propriedades das misturas apresentaram valores aceitáveis para solos utilizáveis em aterros, o que possibilita o aproveitamento de lodo de ETA em misturas com solo a serem empregadas em obras geotécnicas. / In Brazil, WTS is mostly released in water bodies causing silting and deterioration of water quality, destined to treatment with sewage, or disposed of in sanitary landfills or disposal sites of sewage treatment plants mixed with sewage sludge after a partial dewatering process. An alternative for WTS destination is its application, in natura, treated or mixed with soil, as construction material for covers and bottom liners of sanitary and industrial landfills or in embankments in general. Addition of Water Treatment Sludge (WTS) to soils in earthworks may reduce land disposal of WTS and exploitation of natural soils. In this perspective, geotechnical properties of mixtures of a lateritic sandy soil with WTS in proportions 3:1, 4:1, and 5:1 (by wet weight) were evaluated. WTS and soil were subjected to chemical and mineralogical characterization by X-ray fluorescence and X-ray diffraction tests, and determination of loss on ignition, pH, organic matter content, cation exchange capacity, exchangeable bases, and other chemical parameters. Particle-size distribution curve, specific gravity of solids, and Atterberg limits were obtained for WTS, soil and mixtures. One-dimensional consolidation, permeability and undrained triaxial compression tests were carried out on compacted specimens of the soil and the soil-WTS mixtures. Geotechnical characteristics of the mixtures resulted slightly different from those of the soil, on the other hand, previous air-drying affected the compaction parameters of the mixtures, the maximum dry unit weight increased and the optimum water content decreased for a decrease in the initial water content of the compaction test. Compression index of the mixtures were higher than the soil, whereas hydraulic conductivity decreased with WTS addition for different confining pressures and hydraulic gradients. Effective friction angle of the mixtures increased and effective cohesion decreased when increasing the proportion of WTS added in the mixture. Some of those geotechnical parameter values were acceptable for a compacted soil and indicate high possibility of reuse of this waste in geotechnical works.
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