L'étude de sûreté d'un stockage souterrain de déchets radioactifs passe, du point de vue de la géomécanique, par la caractérisation de la zone endommagée induite par le creusement du puits d'accès aux cavités de stockage. L'objet de cette thèse est donc de simuler la réponse hydro-mécanique des argilites de l'Est au creusement du puits d'accès au laboratoire souterrain de Meuse/Haute-Marne, en vue d'une comparaison avec les mesures qui seront acquise in situ en 2005 (expérimentation REP).<br/> Nous avons d'abord analysé l'ensemble des essais mécaniques qui ont été réalisés entre 1995 et 2001. Nous observons que chaque série d'essais a sa propre cohérence, que ce soit en termes de paramètres élastiques, de résistance à la rupture ou de capacité au fluage. Mais il existe de fortes différences entre les séries. Ces différences, qui sont dues au protocoles expérimentaux et non au matériau, nous ont permis de mettre en évidence trois résultats importants : les phases de resaturation imposées par plusieurs laboratoires ont dégradé les propriétés mécaniques des argilites de l'Est, l'existence d'une contrainte effective au sens de Biot n'est pas évidente pour ces argilites, et leur résistance à la rupture augmente nettement avec le séchage.<br/>D'après ces essais, nous avons distingué trois mécanismes de déformation irréversible : compaction, pré-rupture, rupture. Nous les avons décrits chacun par une loi de comportement élasto-plastique simple, fondée sur le critère de Mohr-Coulomb ou de Drücker-Prager, avec un écrouissage linéaire. On obtient alors une loi de comportement complète pour les argilites de l'Est en considérant les trois mécanismes simultanément (plasticité multi-critère).<br/>Enfin, les différentes modélisations que nous avons réalisées permettent de tirer les conclusions suivantes :la prise en compte des déformations irréversibles avant-rupture (compaction et pré-rupture) a pour effet de réduire considérablement l'extension de la zone en rupture qui apparaît autour du puits (par rapport au cas où le comportement est élastique jusqu'à la rupture) ; la diffusion des pressions interstitielles modifie peu la réponse mécanique du massif (en particulier, les déformations plastiques créées lors du déchargement mécanique n'évoluent pas au cours du drainage du massif) ; l'anisotropie des contraintes naturelles horizontales, dont par ailleurs nous confirmons l'existence, influence fortement la zone endommagée autour du puits (polarisation en azimut) ; enfin nous montrons qu'il n'est pas indispensable de simuler le détail des opérations de creusement du puits.

Ce mémoire est consacré à l'étude de la rétention d'eau et de la consolidation des sols non saturés dans un cadre thermo-hydro-mécanique. Il est organisé en deux parties qui concernent respectivement "l'effet de la déformation et de la température sur le comportement hydrique" et "l'effet de la température et de la succion sur le comportement mécanique" de sols non saturés. Dans la première partie, on montre la pertinence du concept de surface caractéristique d'un sol par opposition à la courbe de rétention dont la portée s'avère limitée dans le cas de milieux très déformables. Ce concept est illustré expérimentalement dans le cas d'un sable limoneux argileux. La modélisation mathématique de la surface caractéristique s'appuie sur une importante campagne expérimentale comprenant la mesure d'environ 240 triplets (indice des vides, teneur en eau, succion). Par ailleurs, un modèle de comportement thermo-hydrique est proposé afin de déterminer la surface caractéristique et la courbe de rétention à une température donnée. Ce modèle est validé dans le cas de deux matériaux (une céramique à base de terre cuite et un sable limoneux argileux) testés par l'auteur ainsi que dans le cas d'autres matériaux de la littérature. Enfin, on présente une application à la détermination de la perméabilité des sols non saturés prenant en compte la déformation et la température. Dans la deuxième partie, l'effet de la température et de la succion sur le comportement mécanique est examiné à partir d'essais de consolidation du limon de Sion. Ces essais sont réalisés à différents niveaux de température et de succion. Pour chacun de ces essais, les indices de gonflement et de compression ainsi que la contrainte de préconsolidation sont mesurés. On détermine ainsi l'influence de la température et de la succion sur ces paramètres essentiels du comportement mécanique. Enfin, on propose une fonction d'approximation modélisant l'évolution de la contrainte de préconsolidation en fonction de la température et de la succion.

The present work deals with the behavior of ancient railway sub-structure in France. A statistical study was firstly undertaken on problems occurred in the whole ancient French railway network. The analysis evidenced the particular importance of sub-grade quality for the performance of the sub-structure and the track geometry. Afterwards, an ancient railway line in the West of France was investigated. The analysis showed that the degradation speed of this line was correlated with different parameters such as the nature of sub-grades and the thickness of different layers. An increase trend of degradation speed with the increase in interlayer thickness was identified. The interlayer has a positive impact since it reduces the train-induced stress applied to the sub-grade. The hydro-mechanical behavior of interlayer soil under different conditions (water content, fines content, stress, number of cycles) was investigated. A set of triaxial tests and infiltration tests were performed for this purpose. By analyzing the shear strength properties, the permanent axial strain and the resilient modulus of interlayer soil, we found that the water content and the fines content must be considered together. Adding more fines into the interlayer presents a positive impact under unsaturated conditions thanks to the suction effect, but a negative impact under saturated conditions. The infiltration column tests with drying/wetting cycles showed that the hydraulic conductivity of interlayer soil is governed by fines fraction but did not change significantly with fines content. In order to study the mechanism of interlayer creation and mud pumping, a physical model of 550 mm inner diameter was developed. Soil samples representing the ancient French railway substructure with a ballast layer overlying an artificial silt layer (mixture of crushed sand and kaolin were tested. The effects of monotonic and cyclic loadings, water content and dry unit mass of sub-soil were investigated. It was found that the pore water pressure developed in the sub-soil and the sub-soil stiffness are the key factors for the migration of fine particles or the creation of interlayer/mud pumping. Water is the necessary condition, but it is the soil compressibility that governs the phenomenon to occur

M. Tech. (Chemical Engineering, Faculty of Engineering and Technology), Vaal University of Technology / Acid mine drainage (AMD) is a serious problem associated with mining activities, and it has the potential to contaminate surface and ground water. The aim of this study was to evaluate the performance of constructed wetland and photocatalysis in treating AMD. Three identical unvegetated upflow constructed wetlands packed with natural zeolite (clinoptilolite) and coarse silica sand were made of a cylindrical plastic pipe, and the slurry photocatalyst was prepared using quartz material. A hydro-alcohol thermal method was used to prepare an anatase core-void-shell TiO2 photocatalyst. The results showed that the three unvegetated upflow constructed wetlands (CW) had relatively similar percentage removal of heavy metals despite their varying concentrations within the AMD. The removals were: Fe (86.54 - 90.4%); Cr (56.2 - 64.5%); Mg (56.2 - 67.88%); Ca (77.1 - 100%); and 100% removal was achieved for Be, Zn, Co, Ni, and Mn. The removal of sulphate was also 30%. Heavy metals concentration in CW packing material was significantly higher in the outlet of the constructed wetlands than in the inlet. The adsorption isotherms revealed that the experimental data fitted the Langmuir Isotherms better, which suggested a monolayer coverage of heavy metals on the surface of the adsorbents; thermodynamic studies showed that the nature of adsorption taking place was physical; the kinetics models showed that the adsorption was first order reaction. A higher photocatalytic reduction (62%) of Cr(VI) was obtained at pH 2, 30 mg/l Cr(VI) initial concentration, and three hours of irradiation time. It was also found that the presence of Fe(III) enhanced the reduction of Cr(VI). The core-void-shell TiO2 photocatalyst showed a better activity than the commercial P25 Degussa for the reduction of Cr(VI) to Cr(III). The kinetic studies showed that the reduction of Cr(VI) was first order reaction. Photocatalytic reduction of Cr(VI) in real AMD sample was achieved only for the Douglas North Discharge (DND) sample (68%), and the Fe(III) reduction was found to be 83%. Therefore it was concluded that the combination of constructed wetland and UV/ TiO2 photocatalysis employing anatase core-void-shell TiO2 as a photocatalyst has a potential to reduce the toxicity of Cr(VI)-laden acid mine drainage.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Les sols argileux peuvent présenter des variations importantes de volume lors d’un changement hydrique, tel une période de sécheresse. Ce phénomène de retrait-gonflement des sols argileux est à l’origine de nombreux préjudices aux bâtis ce qui le situe, après les inondations, au second rang des aléas naturels français en matière de coût des dommages : 5 milliard d’euros entre 1988 et 2007. Les maisons individuelles sont les plus touchées par ce phénomène qui provoque un tassement différentiel du bâti à l’origine de sa dégradation (fissures dans les éléments de maçonnerie non armée en particulier). L’objectif de cette thèse est d’étudier la vulnérabilité des bâtis vis-à-vis de l’aléa retrait-gonflement à travers une analyse de l’interaction sol-structure. Ce travail s’est porté sur les trois grands volets suivants : 1 - le comportement hydromécanique des sols argileux, 2 - l’interaction sol-structure, 3 - l’évaluation des dommages structuraux. Le comportement hydromécanique des sols argileux a été modélisé par le concept de surface d’état et intégré dans un modèle d’interaction sol-structure inspiré du modèle de Winkler, avec des approches de plus en plus complexes : cas unidimensionnel tout d’abord, 2D ensuite en assimilant la structure à une poutre, puis en 3D en représentant la structure par une plaque. Ces modèles d’interaction sol-structure permettent de calculer la déflexion relative d’un bâti, en fonction d’une valeur de succion imposée et des propriétés mécaniques ou hydromécaniques de la structure et du sol d’assise. La déflexion relative du bâti est alors comparée à des valeurs seuils afin d’évaluer le dommage.La dernière partie de cette thèse consiste en une étude de faisabilité pour le développement de courbes de vulnérabilités adaptées à la problématique du retrait gonflement. Ces courbes représentent la moyenne des dommages d’un type de bâti conçu sur un type de sol gonflant pour une valeur de succion imposée. Ces courbes ont été développées à partir d’une typologie des sols gonflants et d’une typologie des bâtis issue des bases de données des maisons sinistrées. La moyenne des dommages est calculée par la méthode de Monte-Carlo, en prenant en compte la variabilité des paramètres du bâti. / Clayey soils can present large volumetric deformations in response of water content change. This phenomenon of shrinkage and swelling of clayey soils is recognized as a costly natural hazard throughout the world. In France, this cost is reported between 1988 and 2007 to 5 million Euros, ranking in second class of the French natural hazards in terms of cost of damage after the floods. The individual masonry buildings with shallow foundations are the most affected by this phenomenon that causes a differential settlement of the building leading to cracks in facades and structural elements, especially in unreinforced masonry elements.The objective of this thesis was to study the vulnerability of the building, against the shrink-swell hazard through an analysis of soil-structure interaction. This work was focused on three major points: - Hydro-mechanical behavior of clay soils - Soil-structure interaction - Evaluation of structural damage.The hydro-mechanical behavior of clay soils was considered by the concept of state surface and integrated into a soil-structure interaction model, based on the Winkler model, with increasingly complex approaches: 1D, 2D and 3D by modeling the building behavior respectively by a spring system, the beam element and the plate element. These models of soil-structure interaction are able to calculate the relative deflection of the building, according to the values of imposed suction, mechanical properties of the structure and hydro-mechanical properties of the soil. The relative deflection of the building is then compared to threshold values of the classical damage categories to assess the building damage.Finally a feasibility study was conducted on the development of vulnerability curves adapted to the problem of shrinkage – swelling of clayey soils. These curves represent the average of structural damage versus suction, for each type of building. These curves were developed based on a classification of expansive soils and a building typology outcome from databases of affected buildings. The average damage is calculated by the Monte-Carlo method, taking into account the variability of the building parameters.

ALa terre crue est l’un des principaux matériaux de construction utilisés depuis les temps les plus reculés. C’est un matériau abondant, qui nécessite très peu d'énergie pour sa fabrication et qui ne génère pas de déchets. Construire aujourd’hui avec des matériaux à base de terre crue nécessite de ces derniers des performances mécaniques remarquables. Pour atteindre ces performances, le traitement des sols aux liants est l’une des techniques utilisées pour améliorer la résistance mécanique et la durabilité de ces matériaux. On s’intéresse dans cette thèse à l’étude de la terre crue traitée aux liants pour deux applications différentes : un remblai expérimental pour une application en travaux publics (conception innovante de digue par l’utilisation de matériaux obtenus via un traitement à la chaux) et un béton de terre dénommé « Cématerre » pour une application en bâtiment (éléments structuraux et cloisons présentant de bonnes performances hygro-thermiques). Dans les deux cas, le but est de caractériser, et éventuellement d’améliorer, la résistance mécanique, la rigidité, les caractéristiques hydriques et hydrauliques, ainsi que les propriétés hygro-thermiques. Concernant le béton de terre « Cématerre », les études préliminaires menées selon un protocole expérimental établi conformément au cahier des charges du CSTB, ont permis sa qualification, matérialisée par l’obtention d’une ATEx A. La phase suivante a consisté à améliorer sa formulation avec comme objectif l’amélioration de la résistance mécanique du matériau. Les plans d’expériences utilisés ont permis d’établir des modèles de formulations ciblant les résistances mécaniques recherchées. L’étude du comportement hygro-thermique du béton de terre est abordé en analysant les transferts couplés de chaleur et d’humidité. Pour cela un certain nombre de paramètres hygro-thermiques du matériau Cématerre ont été déterminés au laboratoire. La mesure de ces paramètres a permis la réalisation de simulations hygro-thermiques dynamiques qui ont mis en évidence l’intérêt de ce matériau par rapport au béton « classique ». Concernant le limon traité à la chaux et compacté, les résultats ont montré que le module en petites déformations E augmente avec la contrainte de confinement et l’âge du matériau et décroit légèrement avec le niveau de déformation dans le domaine des contraintes testées. Une loi de type E = ßo1m décrit la variation du module, β et m étant des paramètres fonctions de l’âge et du niveau du déviateur. Par ailleurs, les coefficients de perméabilité saturée et non saturée n’évoluent pas avec le temps de cure. Le fluage volumique ne semble pas non plus être influencé par le temps de cure, autrement dit, l’augmentation de la rigidité du matériau liée au développement des réactions pouzollaniques n’a pas empêché le matériau de fluer autant à 28 jours qu’après un an de temps de cure. / AEarthen construction is one of the most common construction technique used since the earliest times. The raw material is abundant, requires very little energy to manufacture, and does not generate waste. Building today with raw materials made from the earth requires outstanding mechanical performance from such non-fired materials. To achieve this performance, the treatment of the soil with binders is one of the techniques used to improve the strength and durability of these materials. The aim of the present PhD dissertation is to study the treated soils with binders for two different applications: an experimental compacted embankment for application in public works ( a dam innovative design, through the use of materials obtained by treatment with lime ) and earthen concrete called " Cematerre " for application in building ( walls and structural elements with good hygrothermal performance). In both cases, the goal is to characterize and possibly improve the mechanical strength, stiffness, hydric and hydraulic characteristics and the hygrothermal properties. For the earthen concrete " Cematerre ", the preliminary studies according to an experimental protocol under CSTB specifications have led to the so-called “ATEx A” official qualification. The next phase was to improve the formulation with the aim of improving the mechanical strength of the material. The design of experiments has been used to establish models formulations targeting the sought strength. The study of hygrothermal behavior of earthen concrete is addressed by analyzing the coupled transfer phenomenon of heat and moisture. Hygrothermal parameters were determined in the laboratory. The measurement of these parameters has allowed the realization of dynamic thermal simulations that have highlighted the benefit of this material when compared with standard concrete. For silt treated with lime and compacted, the results showed that the small strain modulus E increases with the confining stress and the curing time and decreases slightly with the strain level in the range of stress tested. A power law E = ßo1m describes the variation of the modulus, β and m are functions of the curing time and the strain level. Moreover, the coefficients of saturated and unsaturated permeability do not change with the curing time. The volumetric creep does not appear to be influenced by the curing time, i.e. , the increase in stiffness due to the development of pozzolanic reactions did not prevent the material from creeping as much after 28 days as after a year of curing time.

A receita operacional de uma empresa de geração predominantemente hidrelétrica é composta de duas parcelas: a comercialização de seus contratos de energia e a liquidação na Câmara de Comercialização de Energia (CCEE). A parcela de receita de contratos é previsível, mas a receita proveniente da liquidação da CCEE é de difícil mensuração porque depende das alocações do Mecanismo de Realocação de Energia (MRE) e do Preço de Liquidação das Diferenças (PLD). O trabalho apresenta os conceitos gerais dos componentes que influenciam a receita do mercado de curto prazo e um modelo para sazonalização da energia assegurada que é um dos fatores determinantes para a alocação de MRE e para a liquidação das diferenças. O modelo foi detalhado e implementado em uma ferramenta computacional utilizando Algorítmos Genéticos para a minimização da perda esperada e do risco com a sazonalização. / The operating revenue of power generation companies has two different components: revenues arising from power purchase agreements and from spot market, managed by the Câmara de Comercialização de Energia - CCEE The income of contracts is predictable, but there are a lot of difficulties to do prognosis with the spot market revenue component, because it depends on both the Energy Reallocation Mechanism (MRE) and the spot price (PLD). This text presents the influences of some components in spot market incomes and a model to alocate the assured energy along the year since this is the main factor influencing the MRE and the spot market revenues. The model was formulated and implemented in a computational tool using Genetic Algorithms (AG) to minimize the expected losses and the sazonal risk.

The synthesis of 2,4,6,8-Tetramethylcyclotetrasiloxane (D4H), and Poly(methylhydrosiloxane) (PMHS) average molecular weight 1700-3200 g/mol, were functionalized with different repeat units of methoxy polyethylene glycol (PEG) (n = 8,12,17). These compounds act as polymer electrolytes with a backbone of siloxane and they were prepared via hydro-silylation reaction to be functionalized with different molecular weights of Ally-PEG. The compounds were confirmed by FT-IR, 1H-NMR and 13C NMR spectroscopy. A hydro-silylation reaction between the functionalized AllyPEG of different molecular weights produced four compounds with a low glass transition temperature that could improve comb like polymer electrolytes conductivity by reducing crystalline phase of PEO. Another way to increase the percentage of the amorphous phase of PEO is to blend it with other polymers. The blending method is considered to be an important method to improve the ionic conductivities and dimensional stability of polymer electrolytes. The main advantages of the blend systems are the simplicity of preparation and the ease to control the physical properties. A high molecular weight of poly 2- vinyl pyridine (Mw=200,000) was added to improve the dimensional stability. Differential scanning calorimetry (DSC) thermal analysis shows that all the blend systems will exhibit an increase in the glass transition temperature by increasing the salt content. The other novel synthesis of polymer electrolytes are triglyme borane and borosilicate. They were synthesized via hydro-boration. These compounds were characterized and confirmed by FT-IR, 1H-NMR 13C NMR spectroscopy. The ionic conductivity of both systems, pure and blend, of different compositions were determined at four temperatures i.e. 25°C, 40°C, 55°C and 70°C. A maximum ionic conductivity value of the siloxane blend is 9.1x10-4 S cm-1 and the pure triglyme borane is 2.14x10-3 S cm-1 at ambient temperature. The ratios of ethylene oxide to lithium salt of siloxane blend and pure triglyme borane were 10:1 and 35:1 respectively. These ratios were the highest conductivity obtained in all the electrolyte systems. The ionic conductivity increases with increasing temperature and salt content to reach optimum concentration. This behavior results in ionic transport, which is supported by the segmental motion of the polymer matrix host.

Os processos de união por soldagem entre peças e componentes metálicos são indispensáveis para nossa realidade tecnológica. O processo de soldagem por fricção com pino consumível conhecido como FHPP (Friction Hydro Pillar Processing) é um processo desenvolvido recentemente que ocorre no estado sólido através da fricção entre dois materiais e, com isso, reúne algumas vantagens sobre os processos convencionais de soldagem por fusão. Esta técnica apresenta grande potencial de aplicação na indústria de óleo e gás visando reparos de trincas e descontinuidades em equipamentos e estruturas de aços em geral. Apesar do grande potencial desta técnica, o estudo sobre a sua aplicação para produzir juntas com materiais dissimilares ainda é escasso se comparado com outras técnicas de soldagem. Desta forma, este trabalho tem como objetivo o desenvolvimento e a análise de juntas soldadas utilizando pinos com adição de níquel em chapas de aço com manganês, visando determinar a combinação entre material de pino e parâmetros de soldagem que forneça a junta com melhores características mecânicas e metalúrgicas. Os parâmetros de soldagem que variaram foram: velocidade de rotação e a força axial. Os materiais utilizados nos conjuntos soldados foram chapas de aço ao manganês, classificadas comercialmente como ASTM A516 grau 70, e barras de aço baixo carbono com adição de 3, 6 e 9% de níquel. A análise realizada sobre as juntas abrangeu a caracterização da microestrutura e das propriedades de dureza das regiões específicas da solda além dos ensaios mecânicos de dobramento, tração com micro-amostras e de tenacidade à fratura através do parâmetro CTOD. Todas as soldas tiveram bom preenchimento, porém alguns materiais de pino não proporcionaram boa ductilidade durante o dobramento. As falhas ocorridas durante o dobramento juntamente com os estudos da tenacidade à fratura na zona de ligação mostraram que o acúmulo de inclusões nesta região representa degradação das propriedades mecânicas localmente. Os ensaios de tração com micro-amostras indicam aumento da resistência mecânica na região do material depositado do pino e os valores de CTOD no material termomecânicamente afetado são significativamente maiores do que na zona de ligação, porém não alcançam os valores obtidos nos materiais como não processados. / The processes of union by welding between parts and metallic components are indispensable for our technological reality. The Friction Hydro Pillar Processing (FHPP) process is a newly developed process that occurs in the solid state through friction between two materials and thus has some advantages over conventional fusion welding processes. This technique presents great potential of application in the oil and gas industry aiming repairs of cracks and discontinuities in equipment and steel structures in general. Despite the great potential of this technique, the study of its application to produce joints with dissimilar materials is still scarce compared to other welding techniques. The aim of this work is the development and analysis of welded joints using rod with nickel addition in steel sheets with manganese, in order to determine the combination of rod material and welding parameters that provides the joint with better mechanical and metallurgical characteristics. The welding parameters that varied were: speed of rotation and axial force. The materials used in the welded assemblies were manganese steel plates, commercially classified as ASTM A516 grade 70, and low carbon steel with addition of 3, 6 and 9% nickel. The analysis of the joints included the characterization of the microstructure and the hardness properties of the specific regions of the weld in addition to the bend test, micro-tensile test and fracture toughness through the parameter CTOD. All welds were well filled, however, some rod materials did not provide good ductility during bend test. The failures during folding together with the fracture toughness studies in the bonding zone showed that the accumulation of inclusions in this region represents degradation of the mechanical properties locally. The micro-tensile test indicate increased mechanical strength in the region of the deposited material of the rod and the values of CTOD in the thermomechanically affected material are significantly higher than in the bonding zone, but do not reach the values obtained in the unprocessed material.