The Mw 6.2 February 22nd 2011 Christchurch earthquake (and others in the 2010-2011 Canterbury sequence) provided a unique opportunity to study the devastating effects of earthquakes first-hand and learn from them for future engineering applications. All major events in the Canterbury earthquake sequence caused widespread liquefaction throughout Christchurch’s eastern suburbs, particularly extensive and severe during the February 22nd event. Along large stretches of the Avon River banks (and to a lesser extent along the Heathcote) significant lateral spreading occurred, affecting bridges and the infrastructure they support. The first stage of this research involved conducting detailed field reconnaissance to document liquefaction and lateral spreading-induced damage to several case study bridges along the Avon River. The case study bridges cover a range of ages and construction types but all are reinforced concrete structures which have relatively short, stiff decks. These factors combined led to a characteristic deformation mechanism involving deck-pinning and abutment back-rotation with consequent damage to the abutment piles and slumping of the approaches. The second stage of the research involved using pseudo-static analysis, a simplified seismic modelling tool, to analyse two of the bridges. An advantage of pseudo-static analysis over more complicated modelling methods is that it uses conventional geotechnical data in its inputs, such as SPT blowcount and CPT cone resistance and local friction. Pseudo-static analysis can also be applied without excessive computational power or specialised knowledge, yet it has been shown to capture the basic mechanisms of pile behaviour. Single pile and whole bridge models were constructed for each bridge, and both cyclic and lateral spreading phases of loading were investigated. Parametric studies were carried out which varied the values of key parameters to identify their influence on pile response, and computed displacements and damages were compared with observations made in the field. It was shown that pseudo-static analysis was able to capture the characteristic damage mechanisms observed in the field, however the treatment of key parameters affecting pile response is of primary importance. Recommendations were made concerning the treatment of these governing parameters controlling pile response. In this way the future application of pseudo-static analysis as a tool for analysing and designing bridge pile foundations in liquefying and laterally spreading soils is enhanced.

Les travaux de recherche présentés portent sur l'utilisation des produits de la liquéfaction des écorces d'épicéa dans le phénol pour la préservation du bois. Les produits de la liquéfaction permettent la synthèse d'une résine thermodurcissable de type phénolique. Les résines formulées sont imprégnées dans le bois suivi d'un durcissement in situ. Un prétraitement est mis au point dans le but d'enrichir la fraction phénolique des écorces. Ce prétraitement consiste à hydrolyser les polysaccharides principalement la cellulose et les hémicelluloses dans une solution acide. Ce prétraitement permet d'obtenir un taux de lignine dans les écorces de 60 %, et un taux de cellulose de 28 %. Un procédé de liquéfaction dans un système composé de phénol, d'eau et d'éthanol est optimisé dans le but d'obtenir des taux de liquéfaction supérieur à 85 %, et un taux d'écorces liquéfiées par rapport à la masse de phénol supérieur à 50 %. Les produits de la liquéfaction présentent l'avantage de polymériser sans ajout de formaldéhyde. La durabilité conférée au bois par les résines est bonne, surtout pour les résines phénol/formaldéhyde. Les résines sont peu lessivables. L'imprégnation du bois par les résines provoque un gonflement du bois ce qui améliore la stabilité dimensionnelle de ce dernier / This work focuses on the use of liquefaction products of spruce bark in phenol for the wood preservation. The liquefaction products allow the synthesis of phenolic thermosetting resins. The formulated resins were impregnated into the wood followed by in situ polymerization. A pretreatment was developed in order to increase the phenolic compounds in the spruce bark. This step is an acid hydrolysis of polysaccharides. This pretreatment allowed obtaining a Klason lignin content of 60 %, and a cellulose content of 28 %. A liquefaction process was developed in a mixture of solvent composed of phenol, ethanol, and water. The optimized experimental conditions allowed obtaining a liquefaction yield superior to 85 %, with liqui?ed bark/phenol ratio superior to 50 %. The lique?ed products had the advantage to polymerize without formaldehyde. The resins enhanced the wood durability especially for the phenol/formaldehyde resins. The leaching was low. The wood impregnation allowed a wood swelling, thereby the impregnated wood had a better dimensional stability

Les déchets de bois traités représentent 27% du gisement des déchets dangereux en France. Ces déchets sont incinérés dans des installations classées pour la protection de l’environnement (ICPE). Néanmoins, leur incinération nécessite des équipements robustes et coûteux pour le lavage des gaz et des fumées toxiques. Dans ce contexte, le présent travail a pour objectif d’élaborer et de mette en oeuvre d’autres voies de valorisation énergétique des déchets de bois traités par des procédés thermochimiques. Pour cela, les procédés de pyrolyse et d’hydroliquéfaction ont été mis en oeuvre principalement pour la valorisation énergétique des déchets de bois traités aux sels de CCB (cuivre-chrome-bore) qui représentent 8750 tonnes/an en France. Le bois imprégné de sels de CCB dans nos laboratoires conformément au traitement industriel, a été étudié afin de maîtriser le bilan des métaux dans les différents produits de pyrolyse et d’hydroliquéfaction. Une étude préliminaire de son comportement thermique a été menée par analyse thermogravimétrique dans le but de déterminer l’intervalle de température effectif à sa dégradation massique. Dans cet intervalle de température, les paramètres expérimentaux de pyrolyse lente ont été optimisés pour piéger les métaux dans le charbon. Par la suite, une étude paramétrique par la méthode des plans d’expérience a été réalisée pour la conversion du charbon en bio-huile. De plus, l’optimisation de l’hydroliquéfaction pour la conversion du bois traité en bio-huile a été effectuée. Les résultats montrent que les métaux initialement présents dans le bois traité sont répartis entre la bio-huile et le coke quelque soit la voie de valorisation énergétique empruntée (hydroliquéfaction/pyrolyse+hydroliquéfaction). Cependant la bio-huile présente des caractéristiques proches de celles des biodiesels. L’utilisation de catalyseur au cours de l’hydroliquéfaction du charbon de pyrolyse améliore non seulement la qualité de la bio-huile mais aussi le bilan d’énergie sur le procédé. / The amount of treated-wood waste was estimated to 27% of the deposit of hazardous waste in France. These wastes are incinerated in specials incineration plants “installations classées pour la protection de l’environnement”. However, incineration produces harmful residues and contaminated gases released into the atmosphere inevitably. In this context, this work aims to develop and implement other ways of energy recovery from treated-wood waste using thermo-chemical processes. For this, the pyrolysis and hydroliquefaction processes were performed for energy recovery from CCB treated wood waste (copper-chromium-boron) representing 8750 t / year in France. Natural wood were impregnated with salts of CCB in our laboratories according to industrial processing to control the balance of metals in pyrolysis and hydroliquefaction products. A preliminary study was carried out by thermogravimetric analysis in order to determine the temperature range for effective mass degradation of CCB treatedwood. In this temperature range, the experimental parameters of slow pyrolysis have been optimized to concentrate metals in charcoal. Subsequently, a parametric study was conducted by the method of experimental design for the conversion of coal into bio-oil. In addition, the optimization of the conversion hydroliquefaction treated wood into bio-oil was performed. The results show that the metals initially present in the treated wood are divided between the bio-oil and coke whatever the processes energy recovery used (hydroliquefaction / pyrolysis + hydroliquefaction). However, the immediate characteristics of bio-oil and biodiesel are quite similar. The use of catalyst during charcoal conversion improves the quality of the bio-oil but also the energy balance of the process.

De nombreux tremblements de terre ont provoqué l’effondrement de structures importantes. La conception des structures résistant aux séismes dépend fortement de l’interaction sol-fondation-structure. Cette interaction implique la prise en compte simultanée des mouvements relatifs et des mécanismes de transfert de charge. En ce qui concerne les sols liquéfiables, la génération des pressions interstitielles doit également être prise en compte.Le renforcement des sols compressibles par des pieux est une solution très utilisée pour supporter les structures dans des zones sismiques. Plus récemment, la technique de renforcement par inclusions rigides a été utilisée. La différence entre les deux techniques réside dans le fait que, dans la technique du renforcement par inclusions rigides, un matelas de transfert de charge est intercalé entre la structure et les têtes des inclusions rigides. L’utilisation du matelas permet la dissipation d’énergie liée au séisme.Ce travail de thèse étudie le comportement sismique des sols compressibles renforcés par des pieux (système sol-pieux-structure) et des inclusions rigides (système sol-inclusions-matelas-structure). L’étude est effectuée à l’aide d’une modélisation numérique tridimensionnelle par différences finies avec le code Flac3D. Plusieurs types de sol ont été considérés en prenant en compte des états drainés et non drainés. Pour les cas non drainés, les analyses ont été réalisées à l'aide de simulations hydro-mécaniques couplées. Des modèles constitutifs simples et complexes ont été utilisés pour représenter le comportement du sol. Un amortissement de type Rayleigh a été appliqué pour fournir un amortissement supplémentaire à la partie élastique lorsque des modèles constitutifs élastoplastiques simples ont été considérés.L’objectif de ce travail est d’identifier l’impact des facteurs importants sur la réponse des systèmes analysés. Des nombreux paramètres comme le type de fondation, la fréquence du chargement, les caractéristiques dynamiques de la structure, le profil de sol et la densité relative ont été étudiés. En tenant compte des fondations sur pieux et des inclusions rigides, les conditions aux extrémités des pieux, la configuration du groupe de pieux, la longueur des pieux et l'encastrement des fondations ont également été investigués.Des aspects importants relatifs aux modèles numériques ont également été explorés tels que la géométrie du modèle, les frontières absorbantes, la taille des éléments du maillage, les éléments d'interface, les éléments structurels et le chargement dynamique.Les mouvements et contraintes dans le sol, les structures et les éléments rigides de renforcement ont été analysés et ont permis de mettre en évidence l’influence des divers paramètres étudiés. Cette étude a permis de mettre en évidence l’influence de certains paramètres dans la réponse (accélérations, déplacements, efforts, contraintes, pression interstitielle) des systèmes évalués. Le type de rupture dans les éléments des systèmes étudiés ont également été mis en évidence.Mots-clés: pieux; inclusion rigide; modélisation numérique; analyse dynamique; interaction de la structure du sol; liquéfaction / A great amount of earthquakes have caused the collapse of important structures along the history. The design of earthquake-resistant structures depends greatly of the soil-structure interaction. This interaction implies the consideration of relative movements and load transfer mechanism simultaneously. Dealing with liquefiable soils the generation of pore pressure should also be considered.Pile system constitutes a common foundation of structures resting on soil layers of low stiffness and strength in seismic zones. More recently rigid inclusion systems were utilized. The difference is that in the rigid inclusion systems, the rigid elements are separated from the foundation slab by an earth platform that is able to transfer the surface loads and dissipate energy coming from the seismic loading.This manuscript studies the behavior, through numerical models, of inclusions systems (soil-inclusion-platform-structure) and pile systems (soil-pile-structure) considering soft soils under seismic loadings. Finite difference numerical models were developed using Flac3D. Several types of soils were utilized in drained and undrained conditions. For the undrained cases, the analyses were carrying out using dynamic coupled fluid-mechanical simulations with accuracy the behavior of soils. The Rayleigh damping approach was applied to provide additional damping in the elastic part when simple elasto-plastic constitutive models were considered.The objective of the investigation is the identification of the impact of important factors in the response of the analyzed systems. Factor such as the foundation type, the frequency of the input motion, the dynamic characteristics of the structure, the soil profile and the relative density were investigated. Considering the pile and rigid inclusion foundations, the support conditions, the pile group configuration, the pile length, the embedment of the foundation were also examined.Additional and important aspects of numerical model were also explored like the model geometry, dynamic boundary conditions, element size, interface elements, structural element types, dynamic loading.Results in terms of movements and stresses in the soil, superstructure and rigid elements were obtained. They show the great influence of some parameters in the response (accelerations, displacements, efforts, strains, pore pressure) of the evaluated systems. Others highlight the importance of a type of failure in the elements of the system.Keywords: pile; rigid inclusion; numerical modelling; dynamic analysis; soil structure interaction; liquefaction

A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy, 2016 / The performance in tailings storage facilities (TSFs) of three methods based on the cone penetration test (CPT) to assess liquefaction potential is explored. For two of these methods the investigation highlights potential limitations mostly related with the experimental data that supports some of the equations used by the methods. However, the methodologies yielded mostly correct performance predictions when implemented on TSF case histories in which an undrained response is believed to have occurred. The positive performance of both methodologies must be tempered by the limitations identified in the methods. The steady state line (SSL) is an input of the third method considered. Accordingly, the correlation between the SSL and soil index parameters was investigated using a database of 151 non-plastic soiltypes compiled from data previously reported in the literature. The SSLs were modelled in void ratio (e) - mean effective stress (p') space, using a logarithmic equation. The y-intercept of the SSL is termed Γ, and the slope is termed λ. A direct, and linear (R2 = 0.74) correlation between the minimum void ratio (emin) and Γ was found. Although previous research has explored the effect of non-plastic fines on the SSL, the analysis presented herein shows that the Γ-emin correlation is independent of fines content. The correlation is also independent of the angularity of the particles provided that these are bulky, as opposed to platy. A direct λ-emin correlation was also found; however this correlation is much weaker and probably obscured by uncertainties in void ratio measurements. Triaxial testing was conducted to determine the SSLs of three tailings soiltypes obtained from a single TSF. The trends observed in the resulting SSLs are in agreement with the Γ-emin and λ-emin correlations from the database. An assessment was made of the sensitivity of the third method, which is based on a state parameter (ψ), to variations in λ throughout a single TSF. It was found that in some TSFs, the variations of λ are small enough to be disregarded without significantly affecting the accuracy of ψ. However, in other TSFs it is necessary to estimate how λ varies throughout the deposit. iii / CK2017

Os escorregamentos causados por precipitação intensa ocasionam grandes prejuízos a cada estação chuvosa no sudeste brasileiro. Essa dissertação estudou 2 amostras de solos da região serrana do Rio de Janeiro sob uma nova ótica de análise para escorregamentos. As amostras foram coletadas 4 meses após a ocorrência do megadesastre, onde chuvas com precipitação de 325mm em 48 horas causaram mais de 1500 mortes. Em relatos e vídeos obtidos de movimentos de massa que ocorreram nesse evento foi possível observar que o solo apresentou comportamento de um líquido denso e viscoso, escoando pelas encostas da cidade, ou seja, o solo, encharcado pelas chuvas intensas que ocorreram na região, sofreu liquefação. Esse material viscoso formado pela mistura de solo+água que foi caracterizado através da utilização da reologia. Para isso foram apresentados os conceitos da reologia e dos ensaios reométricos, e as possíveis aplicações para solos e na caracterização de corridas de lama. Foram utilizados três ensaios para caracterizar o solo no estado fluido, que foi o squeeze flow, o reômetro de torque com reometria planetária, e o reômetro de placas paralelas. O principal objetivo para utilização desses ensaios é a praticidade para realização dos ensaios, que tem como características: a rapidez na execução, a coleta de dados é realizada automaticamente, apresentam receptibilidade e a facilidade na execução. Com os resultados obtidos foi possível observar a mudança de comportamento do solo (de um material com comportamento elástico para um material como um fluxo de lama) com a elevação da umidade, para os dois ensaios. Os resultados demonstram que o valor do limite de liquidez calculado através do aparelho de Casagrande é confirmado com esses novos aparelhos, ii sendo que, para esses aparelhos é visível a mudança de comportamento que define o limite de liquidez. Através dos resultados também foi possível determinar que o solo em estado fluido tem seu comportamento regido pelo modelo de Herschel Bulkley. Para tornar os resultados obtidos aplicáveis foi apresentado um capítulo ligando os resultados obtidos da reometria com a possibilidade do solo sofrer liquefação, aliado com os resultados obtidos dos ensaios de caracterização geotécnica. Sendo realizadas análises de estabilidade com os resultados obtidos, correlacionando a inclinação do talude, o nível dágua e a ocorrência da liquefação. / Landslide caused by rainfalls cause major damage each rainy season in southeastern Brazil. This dissertation studied two soil samples from the mountainous region of Rio de Janeiro in a new light analysis for landslides. Samples were collected four months after the occurrence of disaster, when rainfall with intensity of 325mm in 48 hours caused more than 1,500 deaths. In reports and video obtained from mass movements that occurred at this event was observed that the soil responded as a dense liquid, viscous draining the citys landscape. The drenched soil, by heavy rains that occurred in the region, suffered liquefaction. This viscous material formed by mixture of soil and water that was characterized by the use of rheology. In this dissertation was presented the concepts of rheology and rheometric tests for application in soils and characterization of fluid movements. Tree different rheometric tests were performed to characterize the soil in the fluid state, which was the squeeze flow, torque rheometer with planetary geometry and parallel plate rheometer. The main objective of these tests is to use the convenience for the tests, that presents the follow characteristics: the speed of execution, data collection is performed automatically and the testes present repeatability apart from ease of application. With the results we observed the change of soil behavior (of a material with elastic properties for a material that presents the behavior as a mud flow) with increasing humidity for the tests. The results show that the value of the liquidity limit calculated by the Casagrande apparatus is confirmed with these new devices, furthermore with the use of these devices is visible the behavior change that defines the liquid limit. iv Was determined that the Herschel Bulkley model is the one that best represents the behavior of the soil in the fluid state. Was presented a chapter with an application of the results obtained by adding the results of the rheometer with the results of geotechnical characterization tests to determine the possibility of soil suffer liquefaction. To this aim, were performed stability analysis considering the results obtained, correlating the slope inclination, the water level and the occurrence of liquefaction.

Geotechnical engineers are commonly faced with the need to perform ground improvement techniques to achieve the necessary bearing capacity for a project. Some of the most common techniques involve the excavation and replenishment of problematic geomaterial with one of better quality. Common projects, such as road embankments and retaining walls, also require the selection of backfill material. The guidelines for selecting backfill material are typically limited to complying with certain gradation bands, relative densities and allowable fines content. Round-grained silica sand, and beach sand from Boca Raton, FL, were used to generate a total of 16 binary granular mixtures containing different amounts of finer material, for which a series of direct shear tests were conducted. Based on the experimental results, it may be possible to provide an alternative criteria for selecting backfill material based on granulometric parameters and the amount of finer material. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection

Made available in DSpace on 2017-07-21T18:53:13Z (GMT). No. of bitstreams: 1 Maria Carolina Santos.pdf: 831482 bytes, checksum: 8053abff10699b2f862586aa8a3301e7 (MD5) Previous issue date: 2006-01-27 / The application of clean technology concept aims to optimize the extraction process in order to obtain maximum juice, to decrease loss and to manage the generated residue applicability. The use of enzymatic complexes, of cellulases and pectinases, during juice extraction process allows to modify physical-chemical characteristics of the products and to minimize residue generation. This work aimed to study the fermentative behavior of apple juice obtained through the use of clean technology concept, called enzymatic liquefaction. Process and liquefaction products characteristics were compared to extraction by pressing. An increase of 28.43% in total acidity, 28.6% in total nitrogen and 39.38% in phenolic compounds was found in the juice obtained by liquefaction. The pomace presented a decrease of 23.35% in pectine, an increase of 38.3% in ether extract and was not observed statistical difference for total alimentary fiber values. By using enzymatic liquefaction process was observed a decrease of 19% of humid residue, when compared to pressing process. The juices obtained by enzymatic liquefaction and pressing process were submitted for fermentation, in defined conditions of temperature and time, when was undertaken the analysis of biomass production kinetics, ethanol, flavor volatile compounds formation and the total sugar reductor consume. The superior alcohol sum for fermented obtained from liquefaction and pressing was 133.6mg.L-1 and 130.4mg.L-1, respectively. Methanol average levels, resulting from pectin desmetoxilation by pectinesterase activity were 486.24mg.L-1 for liquefaction process and 13.95mg.L-1 for pressing process. / A aplicação do conceito da tecnologia limpa visa otimizar o processo de extração para que o máximo de suco seja obtido, diminuir perdas e gerenciando a aplicabilidade do resíduo gerado. A utilização de complexos enzimáticos, constituídos por celulases e pectinases, na extração de suco permite além de modificar características físico-químicas dos produtos, minimizar a geração de resíduos. Estudar o comportamento fermentativo do suco de maçã obtido a partir o conceito da tecnologia limpa, usando a liquefação enzimática, foi o objetivo deste trabalho. As características do processo e dos produtos da liquefação foram comparadas à extração por prensagem. Foi verificado um aumento em 28,43% na acidez total, 28,6% para o nitrogênio total e 39,38% nos compostos fenólicos no suco obtido por liquefação. No bagaço proveniente da liquefação foi obtida uma diminuição de 23,35% de pectina, um aumento no extrato etéreo de 38,3% e não foi verificada diferença estatística entre os valores obtidos para fibra alimentar total. Com a utilização do processo de liquefação enzimática foi verificada uma redução de 19% na quantidade de resíduo úmido gerado, quando comparado ao processo de prensagem. Os sucos provenientes tanto da liquefação enzimática quanto da prensagem foram submetidos à fermentação, em condições padrão de temperatura e tempo, sendo analisada a cinética de produção de biomassa, etanol, formação dos compostos voláteis do aroma e o consumo de açúcares redutores totais. A soma dos álcoois superiores foi de 133,6mg.L-1 e 130,4mg.L-1 para os fermentados obtidos da liquefação e prensagem, respectivamente. Os teores médios de metanol, resultantes da desmetoxilação da pectina pela atividade da pectinesterase foram de 486,24mg.L-1 para o fermentado obtido da liquefação e 13,95mg.L-1 para o fermentado proveniente da prensagem.

Os escorregamentos causados por precipitação intensa ocasionam grandes prejuízos a cada estação chuvosa no sudeste brasileiro. Essa dissertação estudou 2 amostras de solos da região serrana do Rio de Janeiro sob uma nova ótica de análise para escorregamentos. As amostras foram coletadas 4 meses após a ocorrência do megadesastre, onde chuvas com precipitação de 325mm em 48 horas causaram mais de 1500 mortes. Em relatos e vídeos obtidos de movimentos de massa que ocorreram nesse evento foi possível observar que o solo apresentou comportamento de um líquido denso e viscoso, escoando pelas encostas da cidade, ou seja, o solo, encharcado pelas chuvas intensas que ocorreram na região, sofreu liquefação. Esse material viscoso formado pela mistura de solo+água que foi caracterizado através da utilização da reologia. Para isso foram apresentados os conceitos da reologia e dos ensaios reométricos, e as possíveis aplicações para solos e na caracterização de corridas de lama. Foram utilizados três ensaios para caracterizar o solo no estado fluido, que foi o squeeze flow, o reômetro de torque com reometria planetária, e o reômetro de placas paralelas. O principal objetivo para utilização desses ensaios é a praticidade para realização dos ensaios, que tem como características: a rapidez na execução, a coleta de dados é realizada automaticamente, apresentam receptibilidade e a facilidade na execução. Com os resultados obtidos foi possível observar a mudança de comportamento do solo (de um material com comportamento elástico para um material como um fluxo de lama) com a elevação da umidade, para os dois ensaios. Os resultados demonstram que o valor do limite de liquidez calculado através do aparelho de Casagrande é confirmado com esses novos aparelhos, ii sendo que, para esses aparelhos é visível a mudança de comportamento que define o limite de liquidez. Através dos resultados também foi possível determinar que o solo em estado fluido tem seu comportamento regido pelo modelo de Herschel Bulkley. Para tornar os resultados obtidos aplicáveis foi apresentado um capítulo ligando os resultados obtidos da reometria com a possibilidade do solo sofrer liquefação, aliado com os resultados obtidos dos ensaios de caracterização geotécnica. Sendo realizadas análises de estabilidade com os resultados obtidos, correlacionando a inclinação do talude, o nível dágua e a ocorrência da liquefação. / Landslide caused by rainfalls cause major damage each rainy season in southeastern Brazil. This dissertation studied two soil samples from the mountainous region of Rio de Janeiro in a new light analysis for landslides. Samples were collected four months after the occurrence of disaster, when rainfall with intensity of 325mm in 48 hours caused more than 1,500 deaths. In reports and video obtained from mass movements that occurred at this event was observed that the soil responded as a dense liquid, viscous draining the citys landscape. The drenched soil, by heavy rains that occurred in the region, suffered liquefaction. This viscous material formed by mixture of soil and water that was characterized by the use of rheology. In this dissertation was presented the concepts of rheology and rheometric tests for application in soils and characterization of fluid movements. Tree different rheometric tests were performed to characterize the soil in the fluid state, which was the squeeze flow, torque rheometer with planetary geometry and parallel plate rheometer. The main objective of these tests is to use the convenience for the tests, that presents the follow characteristics: the speed of execution, data collection is performed automatically and the testes present repeatability apart from ease of application. With the results we observed the change of soil behavior (of a material with elastic properties for a material that presents the behavior as a mud flow) with increasing humidity for the tests. The results show that the value of the liquidity limit calculated by the Casagrande apparatus is confirmed with these new devices, furthermore with the use of these devices is visible the behavior change that defines the liquid limit. iv Was determined that the Herschel Bulkley model is the one that best represents the behavior of the soil in the fluid state. Was presented a chapter with an application of the results obtained by adding the results of the rheometer with the results of geotechnical characterization tests to determine the possibility of soil suffer liquefaction. To this aim, were performed stability analysis considering the results obtained, correlating the slope inclination, the water level and the occurrence of liquefaction.

A geração de resíduos provocada pela atividade mineradora é revestida de considerável preocupação ambiental, tanto em função da área envolvida no depósito deste material, quanto pelos impactos causados por eventuais rupturas que possam a ocorrer nestes reservatórios. O método de disposição de resíduos, frequentemente utilizado pelas mineradoras, consiste no bombeamento do material por via úmida até os reservatórios de alteamento contidos através de diques ou barragens. Este processo pode tornar estas áreas suscetíveis à ocorrência de rupturas causadas por liquefação do material. Quando este tipo de evento acontece, tem-se um aumento repentino da poropressão, com consequente redução da resistência ao cisalhamento. A verificação do potencial de liquefação de resíduos de mineração é, portanto, imprescindível à prevenção de impactos ambientais, além de colaborar na execução de projetos geotécnicos mais seguros e econômicos. Neste trabalho são analisados três reservatórios distintos, sendo um composto por resíduo de mineração de ouro e os outros dois por resíduo de mineração de bauxita. Os resultados de ensaios realizados em campo (SCPTU/CPTU e SDMT) são utilizados na avaliação geotécnica dos resíduos, buscando-se verificar a compatibilidade com avaliações já realizadas através de ensaios de laboratório. O potencial de liquefação estática dos materiais é observado em laboratório para baixos níveis de tensões, demonstrando que os resíduos são suscetíveis à liquefação estática. Este comportamento é verificado também na interpretação de ensaios de campo, interpretados através de correlações de natureza semiempírica baseadas na combinação de uma medida representativa de pequenas deformações (módulo cisalhante) combinado a uma medida obtida à grandes deformações (resistência à penetração) que, combinadas, permitem a determinação do parâmetro de estado do material. A primeira proposta consistiu na definição de uma fronteira entre materiais de comportamento contrátil e dilatante no espaço G0/qc versus p’/pa. Esta proposta apresentou uma resposta adequada, entretanto, a concentração de todos os pontos referentes aos resíduos analisados, possivelmente suscetíveis ao fenômeno de liquefação estática, numa mesma região gráfica, somente foi possível no espaço G0/qc versus qc1. Neste espaço a separação entre materiais de comportamento dilatante e contrátil foi possível com a inserção de uma fronteira empírica. Este estudo demonstrou a boa sensibilidade dos parâmetros G0 e qc ao fenômeno de liquefação estática. A suscetibilidade à liquefação cíclica dos resíduos de mineração de ouro e bauxita também foi verificada através de correlações com resultados de ensaios de campo. Esta análise indicou a possibilidade de ocorrência do fenômeno para os mais baixos níveis de magnitude de sismo atuante. / Waste generation caused by mining activity emerges as an environmental concern, both because of the large area involved in deposits of this material, as well as the possible impacts caused by occasional failures that may occur in these deposits. The method of waste disposal, often used by mining companies, consists by pumping wet material in sequence until completion of the reservoirs contained by dikes or dams. This process makes these areas susceptible to the occurrence of the liquefaction failures. When this type of event happens there is a sudden increase in pore pressure with consequent reduction shear strength, which can result is risk of containment structures. Therefore, verification of liquefaction potential of these materials is essential in the prevention of environmental impacts. The present work analyzes three different reservoirs, one consisting of gold mining tailings and the other two of bauxite mining tailings. The results of field tests (SCPTU/ CPTU and SDMT) are used in geotechnical evaluation of tailings in order to verify the compatibility with evaluations already carried out through laboratory tests. The static liquefaction potential observed in laboratory at low levels of stresses is consistent with field assessment from in situ tests. Semiempirical correlations based on field tests are based on small strain measurements (shear modulus) combined with large strain measurements (penetration resistance), that are used to defined the state parameter of the material. The first proposal consisted in defining a boundary between materials of contractive and dilatant behavior in space G0/qc versus p’/pa. The proposal presented an appropriate response, however, the concentration of all analyzed points, possibly susceptible to static liquefaction phenomenon, in the same graphical region was only possible in space G0/qc versus qc1. In this space the separation between materials of contractive and dilatant behavior was possible with the inclusion of an empirical boundary. This study demonstrated the good sensitivity of the parameters G0 and qc to the static liquefaction phenomenon. The cyclic liquefaction susceptibility of the gold and bauxite mining tailings was also verified by correlation with field tests results. This analyzes indicated the possibility of occurrence of the phenomenon to the lowest levels of earthquake magnitude.