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Zhu, Liping. "Utilisation de la simulation moléculaire pour mieux évaluer la déformation et la rupture des roches riches en argile." Thesis, Université de Lille (2018-2021), 2021. https://pepite-depot.univ-lille.fr/ToutIDP/EDENGSYS/2021/2021LILUN038.pdf.
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La compréhension des caractéristiques mécaniques des matériaux à base d'argile est essentielle en sciences de la terre et dans diverses applications industrielles. L'argile, en tant que composant principal de ces matériaux hétérogènes, joue un rôle important dans le comportement mécanique de ces matériaux. A travers la simulation de la Dynamique Moléculaire (DM), la présente thèse est consacrée à l'étude des comportements mécaniques des minéraux argileux gonflants à l'échelle atomique en mettant l'accent sur les influences de la teneur en eau, du chemin de chargement, de l'anisotropie et de la contrainte moyenne. La thèse est composée de trois parties principales. La première partie se concentre essentiellement sur les propriétés mécaniques de la Na-montmorillonite sèche (MMT) qui est soumise à un chargement triaxial de compression et d'extension avec différentes contraintes moyennes constantes. Une série de simulations de dynamique moléculaire a été réalisée respectivement dans les directions parallèle et perpendiculaire aux couches cristallines. Les effets de la trajectoire de chargement, de la contrainte moyenne et de l'anisotropie sur les propriétés mécaniques de la MMT sèche à l'échelle atomique sont étudiés et analysées en détail.La deuxième partie étudie les influences de la teneur en eau sur les propriétés physiques et mécaniques sous compression triaxiale avec une contrainte moyenne constante. Dans un premier temps, la propriété de gonflement est caractérisée par la relation entre la distance inter-couches et le degré d'hydratation. Puis, la relation contrainte-déformation est obtenue. De plus, la microstructure et la connexion inter couche des systèmes MMT hydratés à une, deux ou trois couches entre l'état initial et l'état de défaillance ont été entièrement analysées. Enfin, les mécanismes essentiels déclenchant leur rupture à l'échelle atomique sont caractérisés et analysés. La troisième partie est consacrée à la description des déformations de fluage de la MMT. Grâce à la simulation MD, les trois phases caractéristiques de fluage ont été clairement identifiées. Les effets du niveau de contrainte appliqué, Tension de dérive, de la température et des orientations du chargement sur les réponses dépendantes du temps de la MMT ont été étudiésUnderstanding the mechanical characteristics of clay-based materials is critical in earth sciences and a variety of industrial applications. Clay, as the main component in these heterogeneous materials, plays a significant role in the mechanical behavior of such materials. Through the Molecular Dynamics (MD) simulation, the present thesis is devoted to investigating the mechanical behaviors of swelling clay minerals at atomic scale by putting the emphasis on the influences of water content, loading path, crystal structure anisotropy and mean stress. The thesis is composed of three parts. The first part mainly focuses on the mechanical properties of dry Na-montmorillonite (MMT) which is subjected to triaxial compression and extension loading with different constant mean stresses. A series of Molecular Dynamics (MD) simulations have been carried out respectively in the parallel and perpendicular directions to crystal layers. The effects of loading path, mean stress and anisotropy on mechanical properties of dry MMT at atomic scale are fully studied and discussed. The second part investigates the influences of water content on the physical and mechanical properties under triaxial compression with a constant mean stress. At first, the swelling property is characterized by the relationship between inter-layer distance and the extent of hydration. Secondly, the stress-strain relationships are obtained for different water contents. In addition, the micro-structure and inter-layer connection of the dry, one-, two-, three-layer hydrated MMT systems between initial and failure states have been analyzed in-depth. At last, the key mechanisms triggering their failure at the atomic scale are identified and analyzed. The third part is devoted to describing the creep deformation of MMT. Through the MD simulation, three representative creep stages have been clearly characterized. The effects of applied stress level, deviatoric stress, the temperature and microstructure orientation on the time dependent responses of MMT have been investigated
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Geddes, Jill. "Quantification of swelling clays in mineral mixtures and rocks using infrared spectroscopy." Thesis, Sheffield Hallam University, 2006. http://shura.shu.ac.uk/19682/.
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The use of a chemometric method, partial least squares (PLS) regression and the infrared technique, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was developed for the quantification of minerals in synthetic mixtures and sandstone rocks. Particular emphasis was directed towards quantifying swelling clays since the proportion of swelling minerals present in a reservoir rock influence the composition of fluids injected into the rock to enhance oil recovery. In the first study, the capability of PLS with DRIFTS was demonstrated when low quantities of swelling mineral, smectite, were determined in synthetic mixtures with the non-swelling mineral, kaolinite, and an additional mineral, calcite. A substantial improvement in the detection limit of smectite was found using this method since lower quantities could be determined (with a maximum error of 3.8 wt%) than had been determined by previous workers using a peak fitting technique. An initial investigation of seven different types of sandstone rocks was carried out by visual inspection of XRD traces of powder and rock samples. In this work mineralogical heterogeneity was found along the length of the different sandstone cores investigated. Ideally a representative sample would be one collected from a of ball milled sample of a large portion of a core. The main programme of research was the development of a PLS model consisting of eleven mineral components, to resemble the composition of a real sandstone. This PLS model was used for the quantification of components in synthetic mineral mixtures using their DRIFTS spectra. The maximum error for predicting all the components was +/-2.8 wt%. This was in the same order as errors reported by other workers for quantification of minerals using XRD.The same PLS model was used to quantify components in seven different types of sandstone and the results have been compared with studies by independent investigators using different techniques. The PLS model predicted components in the sandstones which contained relatively high concentrations of feldspars and clays, accurately, with all components predicted within +/-2.8 wt%. PLS model was optimized in order to obtain more accurate quantification of components in the sandstones, in particular for the "cleaner" sandstones, i.e. those which contained low concentrations of feldspars and clays. Some improvement in accuracy was found. The PLS model developed in this thesis, however, was most accurate for prediction of components in sandstones which contained higher concentrations of feldspars and clays.
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Andrea, Martijn. "The anisotropic elastic properties of clay-rich rocks." Thesis, Imperial College London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243413.
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Kemaloglu, Sarp. "Numerical Analysis Of Settlement, And Stress Concentration Ratio In Clayey Soils Reinforced By Floating Single Aggregate Piers." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605190/index.pdf.
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This study discusses the results of numerical modeling aspect of aggregate pier foundations (aggregate piers) in soft, compressible soils. FLAC 2D (Fast Lagrangian Analysis of
Continua), a finite difference code is utilized in the analyses. Use of axisymmetry enabled to visualize a three dimensional model throughout this research.
The primary objective of this research is to make comparisons for stress concentration ratio &lsquon&rsquo
, and settlement reduction ratio b for given variables consisting of length, diameter, elastic modulus of the aggregate piers, and foundation pressures. Analyses have been carried out with 1, 1.5, 2, and 3 m long piers with diameters of 60 cm, and 80 cm, placed under a circular footing in 1.30 m diameter. Two values for elastic modulus of the piers have been used to reflect the effect of pier stiffness on settlement behavior. Analysis and design methodology have been carried out in three stages. The first stage consists of modeling the matrix soil with an elastic constitutive model and exerting foundation pressures to first check the accuracy of the mesh by comparing the effective vertical stress and settlement values by analytical methods. Once satisfactory results are achieved, modeling of a rigid foundation is carried out. Consequently, aggregate piers are modeled and loaded. For foundation pressures, a range of values consisting of 25, 50, 75, and 100 kPa have been chosen to see the behavior of piers under variable foundation pressures. There are solid outcomes of this study. It concludes by stating that the settlement behavior of piers having L/d ratios greater than 3.75, are alike. Thus, there is almost no additional settlement improvement achieved with piers longer than 3 m with 60 cm pier diameter.
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Acaba, Joseph Michael. "Primary Sediment Production from Granitic Rocks in Southeastern Arizona." Thesis, The University of Arizona, 1992. http://hdl.handle.net/10150/231212.
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Isolated granitic rock bodies (granites, granodiorites, quartz monzonites) in the vicinity of Benson in southeastern Arizona were studied to trace the behavior of rock weathering. Thin sections of fresh granites were examined to characterize the original mineralogy which consisted mainly of quartz, feldspars, and micas. The weathering products show up on the granites as grus and soil profiles as well as down slope in the basin deposits. X -ray diffraction studies of the < 2 micrometers fraction of the weathering products proved illite, smectite, illite-smectite mixed layer, and kaolinite to be the dominant clays; quartz and feldspar also persisted into this size fraction. Silt sized material produced similar results. The quartz monzonite of Texas Canyon afforded a special study of the initial weathering stages of feldspars and micas. In the < 2 micrometers fraction obtained from granitic material placed in an ultra sonic bath, the feldspars weathered to a Na-montmorillinite while biotite weathered to vermiculite.
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Sharma, Alok. "Molecular Dynamics simulation of rock and clay minerals to estimate their mechanical properties." Thesis, Virginia Tech, 2006. http://hdl.handle.net/10919/40928.
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Macroscopic analyses of rocks have produced acceptable results for many problems. These problems are simple, involving normal conditions. But a need is arising to study these rocks under extreme conditions, like high temperatures, projectile penetration and extreme pressures. Behavior of rocks under these conditions cannot be predicted using common macroscopic analyses at normal conditions. Nanostructure of the rock governs the behavior of rock under such situations. Hence, there is a need to study these materials using micro molecular mechanics.
There is also a theory that failure in a rock mass is governed by the formation and propagation of microscopic cracks. The development of these can be observed and studied using the nanoscale analyses. A new science is emerging which deals with manipulating the nanostructure of materials. It may be possible in near future to improve the properties of materials into more desirable ones, by changing their nanofabric. These prospects make the nanoscopic analyses of rocks very intriguing.
This research aims at developing methods to analyze rocks, clays and other geotechnical materials to study their nanolevel properties. Molecular Dynamics simulation is the most commonly used method in molecular mechanics. A software program TINKER was used for developing the simulation. Using this, MD simulation was performed on a (14,1) carbon nanotube for validation purposes. Later on simulations were performed on rock minerals such as quartz, albite and calcite and clays such as kaolinite and palygorskite. The simulated results are compared with published data on mechanical properties of rock and clay minerals.Master of Science
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Bagheri, Meghdad. "Experimental investigation of the time- and rate-dependent behaviour of unsaturated clays." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/55534/.
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With the aim to achieve a better understanding of the time- and rate-dependent behaviour of unsaturated clays, particularly stiff natural clays, a critical review of the literature and a program of laboratory testing were carried out as part of this research. With emphasis on examining the effect of suction on viscous response, mainly primary and secondary consolidation (creep), stress-relaxation, and rate-dependency, a series of conventional multi-stage loading (MSL) oedometer tests, long-term single-stage loading (SSL) oedometer tests, and advanced constant-rate-of-strain (CRS) oedometer tests were carried out on natural and corresponding reconstituted specimens of a stiff clay namely, London Clay, retrieved from a site in the Isle of Sheppey, UK. The results obtained provide a significant contribution to the existing database and address important knowledge gaps highlighted from the literature review. The experimental studies performed included; a) An investigation of the effect of water reservoir surface roughness on the cavitation mechanism and performance of a newly designed high-capacity tensiometer (HCT), with regard maximum sustainable suction (smax) and maximum duration of measurements (tmax). b) An examination of the influence of soil suction on the primary and secondary consolidation of natural and reconstituted London Clay from a set of MSL and SSL oedometer tests. c) Characterisation of the stress-relaxation behaviour of the reconstituted London Clay subjected to suction and strain-rate variations from a set of CRS oedometer tests in an in-house designed suction-monitored cell. d) An examination of the coupled effects of suction and strain-rate on one-dimensional (1D) stress-strain response of reconstituted London Clay. Based on the experimental findings, the validity of the empirical relationships proposed in the literature for correlating time- and rate-dependency coefficients was examined and necessary modifications were proposed. The main experimental findings can be outlined as: - The mechanism of cavitation in tensiometers is indeed influenced by the surface roughness of the water reservoir. The new approach for expanding the range and duration of suction measurements for a newly designed HCT, based on hydrophilic coating of the reservoir walls, sounds promising. - The compression index (Cc) and creep index (Cαe) and the ratio α = Cαe/Cc for Sheppey London Clay are stress- and suction-dependent. The hypothesis of constant α for natural clays, as suggested by Mesri et al. (1994), is therefore rejected. - The volumetric creep deformations of unsaturated stiff clays appear to be relatively simply modelled by a creep law based on a power function. - A coupled effect of suction and strain-rate on 1D compression response was identified. At a constant suction, the higher the strain-rate, the higher the apparent preconsolidation pressure (σ'p). Similarly, at a constant strain-rate, the higher the suction, the higher the σ'p. - The values of relaxation coefficient (Rα) differ in saturated and unsaturated states. However, a clear relationship between Rα and suction was not found. The Rα = Cαe/Cc relationship, suggested by Yin et al. (2014) for saturated soft clays, appears, with an approximation, to be valid for the unsaturated stiff London Clay in the range of applied vertical stresses and soil suctions in this study. - The process of stress-relaxation in unsaturated clays is highly influenced by factors such as soil suction, pre-relaxation strain, stress, and strain-rate.
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Hart, Megan Leanore. "Membrane properties of intact rock cores of Burlington Limestone, Jefferson Dolomite, Darrington Phyllite, and low permeability concrete." Diss., Rolla, Mo. : Missouri University of Science and Technology, 2009. http://scholarsmine.mst.edu/thesis/pdf/Hart_09007dcc80699aec.pdf.
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Thesis (Ph. D.)--Missouri University of Science and Technology, 2009.Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed August 21, 2009) Includes bibliographical references.
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Jones, Marilyn Gail 1963. "Clay mineralogy and petrology of the Lower Cretaceous fine-grained clastic rocks, southeastern Arizona." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/558100.
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Kishimoto, Angelica Mariko Naka. "Hydraulic Performance and Chemical Compatibility of Mineral Barriers to Mitigate Natural Contamination from Excavated Rocks." 京都大学 (Kyoto University), 2014. http://hdl.handle.net/2433/188879.
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Webber, J. Beau W., Philip Bland, John H. Strange, Ross Anderson, and Bahman Tohidi. "Why you can’t use water to make cryoporometric measurements of the pore size distributions in meteorites – or in high iron content clays, rocks or concrete." Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-191847.
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Many porous materials have high susceptibility magnetic gradients in the pores, due to the presence of iron or other magnetic materials. Thus if probe liquids are placed in the pores they exhibit fast decaying signals with a short T2*. Usually the actual T2 of the liquids is also reduced, due the presence of paramagnetic ions in the pore walls.
The usual solution in NMR is to measure an echo (or echo train) at short times. However, recent work [J. Phys.: Condens. Matter 19, 415117, 2007.] has shown that water/ice systems near a pore wall form rotator phase plastic ice, with T2 relaxation times in the region of 100 to 200 ms. Thus if a NMR cryoporometric measurement is attempted with a measurement time significantly less than 1 or 2 milli-seconds, the result is to make a measurement based on the phase properties of the brittle to plastic ice phase transition, not that of the brittle ice to water phase transition. This gives rise to artefacts of small pore sizes that may not actually be present. This work successfully uses a-polar liquids instead.
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Webber, J. Beau W., Philip Bland, John H. Strange, Ross Anderson, and Bahman Tohidi. "Why you can’t use water to make cryoporometric measurements of the pore size distributions in meteorites – or in high iron content clays, rocks or concrete." Diffusion fundamentals 10 (2009) 3, S. 1-3, 2009. https://ul.qucosa.de/id/qucosa%3A14092.
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Many porous materials have high susceptibility magnetic gradients in the pores, due to the presence of iron or other magnetic materials. Thus if probe liquids are placed in the pores they exhibit fast decaying signals with a short T2*. Usually the actual T2 of the liquids is also reduced, due the presence of paramagnetic ions in the pore walls.
The usual solution in NMR is to measure an echo (or echo train) at short times. However, recent work [J. Phys.: Condens. Matter 19, 415117, 2007.] has shown that water/ice systems near a pore wall form rotator phase plastic ice, with T2 relaxation times in the region of 100 to 200 ms. Thus if a NMR cryoporometric measurement is attempted with a measurement time significantly less than 1 or 2 milli-seconds, the result is to make a measurement based on the phase properties of the brittle to plastic ice phase transition, not that of the brittle ice to water phase transition. This gives rise to artefacts of small pore sizes that may not actually be present. This work successfully uses a-polar liquids instead.
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Skinner, Damien. "A comparison of electrical methods for the detection of hydraulic pathways in a fractured rock aquifer, Clare Valley, South Australia /." Title page, contents and abstract only, 2001. http://web4.library.adelaide.edu.au/theses/09SB/09sbs6285pdf.
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Xu, Wenjie. "Investigation of Gas Migration in saturated Argillaceous Rock." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-132511.
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Gas migration in saturated argillaceous rock is studied in this work. Dependent on the pressure level the gas transport process is controlled by different mechanisms. Gas injection tests have been carried to investigate the gas transport process in low permeable argillaceous rock. We focus on the Opalinus Clay, which has been widely researched and is important for searching possible host rock of the radioactive waste disposal. Gas injection tests at different scales (laboratory, in-situ borehole and in-situ tunnel test) are intensively investigated in this work. The measurements of the tests are analysed and interpreted with numerical modelling method.
A coupled multi-phase flow and mechanical model has been developed and implemented in the scientific computed codes OpenGeoSys (OGS). In the applied numerical model the relationship between capillary pressure and water saturation degree is described with van Genuchten model. The Darcy’s law is used for the phase flux, and the relative permeability of both water and gas phase is considered. The deformation process is calculated with elastic perfect-plastic model. The anisotropic hydraulic and mechanic behaviours of the Opalinus Clay are involved in the numerical model. The hydraulic anisotropy is controlled by the permeability tensor. The elastic deformation process is modelled by generalized Hooke’s law. The plastic behaviour is calculated with return mapping algorithm, and the anisotropy is considered with a so called microstructure tensor method. The permeability change during the gas injection is described using pressure dependent or deformation dependent approach. With considering the permeability evolution the measured data can be in the numerical model quantitatively represented, and test observations can be interpreted.
Under laboratory condition it can be determined that the specimen permeability is reduced during compression. The significant permeability increase takes places when the gas injection pressure higher than the confining pressure. By the in-situ tests damage zone can be generated due to the drilling of boreholes and tunnel. The highly permeable areas dominate the hydraulic process. Fluid flows through the damaged zone into the not sealed section, e.g. the seismic observation boreholes by the in-situ borehole tests and the section out of the megapacker by the in-situ tunnel tests.
In this work, the two phase flow controlled and pathway dilatancy controlled gas migration mechanisms are successfully simulated. The developed numerical model can be used to investigate the gas injection tests at different scales and conditions.
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Gray, Stuart. "Groundwater remediation using a coal washery discard permeable reactive wall." Access electronically, 2005. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20061017.133840/index.html.
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Giouse, Hélène. "Proprietes petrophysiques et resistivite des gres argileux petroliferes." Paris, ENMP, 1987. http://www.theses.fr/1987ENMP0060.
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La presence d'argile dispersee dans les reservoirs de petrole greseux pose un probleme d'interpretation des diagraphies de resistivite a cause de leur conductivite de surface. On presente une revue bibliographique des phenomenes physiques mis en jeu au sein du reservoir et une analyse critique des formations existantes: on examine en particulier les formules de waxman et smits et celle du dual water. L'etude experimentale des proprietes petrophysiques des roches magasins met en evidence l'importance de la texture de l'argile. Une nouvelle equation "double conducteur-double effet" est proposee. Des mesures de resistivite sur echantillons partiellement satures en huile ont montre qu'il est necessaire de distinguer plusieurs domaines de saturation en eau avec des lois differentes
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Bonnelye, Audrey. "Etude des propriétés physiques et mécaniques des argilites : de la déformation en laboratoire aux failles naturelles." Thesis, Cergy-Pontoise, 2016. http://www.theses.fr/2016CERG0858.
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Les argilites, sont définies comme étant des roches comportant une large fraction de minéraux argileux. Leurs propriétés physiques et mécaniques présentent un intérêt pour l’étude du comportement hydro-mécanique des failles dans la partie supérieure de la croûte mais aussi pour la compréhension des roches couvertures de réservoirs d’hydrocarbures ou pour l’expertise de la pérennité du stockage de déchets radioactifs.Cette thèse propose deux approches afin de comprendre l’organisation de la déformation dans ce type de matériau, une première purement mécanique sur des échantillons intacts et la seconde s’intéressant aux propriétés physiques de matériaux déformés. Pour cela, nous avons étudié les argilites de Tournemire (Tunnel expérimental de l'IRSN, Aveyron, France).La première partie consiste en une série d’essais triaxiaux. Nous avons déterminé les enveloppes de rupture de trois groupes d’échantillons carottés avec des orientations différentes par rapport au litage (0°, 45°, et 90°). Pour chaque orientation, sept expériences ont été réalisées à différentes pressions de confinement (2.5, 5, 10, 20, 40, 80, 160 MPa). L’influence de la vitesse de déformation a été établie en comparant des expériences réalisées avec des vitesses de déformation différentes (10-7 s-1 et 10-5 s-1). Pendant les expériences, les vitesses d’ondes P et S ont été enregistrées selon différents angles par rapport au litage afin de quantifier l’évolution de l’anisotropie des propriétés élastiques.Cette partie permet de mettre en évidence l’importance de l’orientation du litage par rapport à la contrainte principale sur la résistance mécanique de nos échantillons. De plus, un modèle micromécanique basé sur le « wing crack » permet d’expliquer l’anisotropie mécanique de nos argilites par l’anisotropie de la ténacité KIC.Par ailleurs, on constate que l’évolution de l’anisotropie des propriétés élastiques dépend elle aussi de l’orientation considérée. Lors de la compression, l’orientation 90° présente d’importantes variations pouvant aller jusqu’à une inversion de l’anisotropie, alors que les vitesses n’évoluent que très peu pour l’orientation 0°. Ces variations ont été quantifiées par les paramètres de Thomsen. L’étude des vitesses élastiques et celle des microstructures, permettent de mettre en évidence l’importance des processus plastiques comme la réorientation des minéraux au cours de la déformation.La seconde partie consiste en une étude pétrophysique (vitesses des ondes P, ASM, densité, saturation, porosité) d’échantillons provenant d’un forage traversant une zone de faille. Le but est de quantifier la variation de ces propriétés à l’approche du cœur de faille.Un protocole d’échantillonnage et de mesure a été mis en place. Le protocole comporte une première série de mesures directement sur le terrain afin de s’affranchir des problématiques liées à la préservation des échantillons (notamment pour les mesures de porosité/densité/saturation). Par la suite, des échantillons ont été prélevés pour réaliser des mesures à la fois dans le cadre de cette thèse (vitesses des ondes P et ASM) mais aussi dans d’autres laboratoires (étude de la composition minéralogique, CT-scan).A partir des observations, on caractérise :• Une zone saine caractérisée par des échantillons ne présentant pas ou très peu de fracturation• Une zone endommagée qui présente un grand nombre de fractures calcifiées• Une zone de cœur caractérisée par une déstructuration totale (pas de bedding apparent) et des variations de couleur.Notre étude met en évidence une signature physique propre à chaque zone de cette faille avec notamment une diminution de l’anisotropie des échantillons en zone endommagée fortement marquée. De plus, des mécanismes de rotation de la stratigraphie similaires à ceux observés à l’échelle des microstructures lors de la déformation expérimentale ont été observésShales or clays are defined as rock having a large proportion of clay minerals. Their physical and mechanical properties are of interest for the study of the hydro-mechanical behavior of faults in the uppermost crust but also for the understanding of the cap rocks of hydrocarbon reservoirs or for the expertise of the durability of radioactive waste storage.This thesis proposes two complementary approaches to understand the organization of the deformation in this type of material, a first purely mechanical on undisturbed samples and the second focusing on the physical properties of deformed materials. During this thesis, we studied Tournemire shales (IRSN tunnel, Aveyron, France).The first part consists in triaxial tests. We determined the failure envelopes of three sets of core samples with different orientations with respect to bedding (0 °, 45 ° and 90 °). For each orientation, seven experiments were performed at different confining pressures (2.5, 5, 10, 20, 40, 80, 160 MPa). The influence of the strain rate was determined by comparing experiments with different strain rates extending over two orders of magnitude (between 〖10〗^(-7) s^(-1) and 〖10〗^(-5) s^(-1)). During the experiments, the P and S wave velocities were recorded from different angles with respect to the bedding to quantify the evolution of the anisotropy of the elastic properties according to the imposed stress.This section allows to highlight the importance of the orientation of bedding relatively to the principal stress applied on our samples. It is noted for example that the weakest orientation is 45 ° and 90 ° the strongest orientation. In addition, a micromechanical model based on the "wing crack" theory helps to explain the mechanical anisotropy of our argillites by the anisotropy of the fracture toughness K_Ic.Moreover, it is found that changes in the anisotropy of the elastic properties also depends on the bedding orientation. During compression, the 90 ° orientation has significant variations up to a reversal of the anisotropy, whereas the elastic wave velocities show little changes for 0 ° orientation. These variations were quantified by Thomsen parameters. The study of elastic velocities and of microstructures of our samples highlight the importance of the plastic processes such as reorientation of minerals during deformation.The second part consists of a petrophysical study (P wave velocities, ASM, density, saturation, porosity) of samples from a borehole drilled through a fault zone. The goal here is to quantify the variation of these properties as we approach the fault core.A protocol of sampling and measurement was established to realize a complete study of drillings. The protocol includes a first serie of measures directly in the field in order to overcome the problems linked to the preservation of samples (especially for porosity measurements / density / saturation). Subsequently, samples were taken for measurements both in the context of this thesis (P wave velocities and ASM), but also in other laboratories (study of the mineralogical composition, CT-scan).Three fault zones were identified from field observations:• An intact zone characterized by samples with no or very little fracturing• A damaged zone that includes a large number of calcified fractures• A fault core zone characterized by a complete breakdown (no apparent bedding) and color variations.Although these areas were determined on observation criteria, our study demonstrates an own physical signature for each zone of this fault with an important decrease in the anisotropy of the samples from fault core. In addition, bedding rotation with similar mechanisms to those observed at the microstructural scale during the experimental deformation was observed
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Shahraeeni, Mohammad Sadegh. "Inversion of seismic attributes for petrophysical parameters and rock facies." Thesis, University of Edinburgh, 2011. http://hdl.handle.net/1842/4754.
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Prediction of rock and fluid properties such as porosity, clay content, and water saturation is essential for exploration and development of hydrocarbon reservoirs. Rock and fluid property maps obtained from such predictions can be used for optimal selection of well locations for reservoir development and production enhancement. Seismic data are usually the only source of information available throughout a field that can be used to predict the 3D distribution of properties with appropriate spatial resolution. The main challenge in inferring properties from seismic data is the ambiguous nature of geophysical information. Therefore, any estimate of rock and fluid property maps derived from seismic data must also represent its associated uncertainty. In this study we develop a computationally efficient mathematical technique based on neural networks to integrate measured data and a priori information in order to reduce the uncertainty in rock and fluid properties in a reservoir. The post inversion (a posteriori) information about rock and fluid properties are represented by the joint probability density function (PDF) of porosity, clay content, and water saturation. In this technique the a posteriori PDF is modeled by a weighted sum of Gaussian PDF’s. A so-called mixture density network (MDN) estimates the weights, mean vector, and covariance matrix of the Gaussians given any measured data set. We solve several inverse problems with the MDN and compare results with Monte Carlo (MC) sampling solution and show that the MDN inversion technique provides good estimate of the MC sampling solution. However, the computational cost of training and using the neural network is much lower than solution found by MC sampling (more than a factor of 104 in some cases). We also discuss the design, implementation, and training procedure of the MDN, and its limitations in estimating the solution of an inverse problem. In this thesis we focus on data from a deep offshore field in Africa. Our goal is to apply the MDN inversion technique to obtain maps of petrophysical properties (i.e., porosity, clay content, water saturation), and petrophysical facies from 3D seismic data. Petrophysical facies (i.e., non-reservoir, oil- and brine-saturated reservoir facies) are defined probabilistically based on geological information and values of the petrophysical parameters. First, we investigate the relationship (i.e., petrophysical forward function) between compressional- and shear-wave velocity and petrophysical parameters. The petrophysical forward function depends on different properties of rocks and varies from one rock type to another. Therefore, after acquisition of well logs or seismic data from a geological setting the petrophysical forward function must be calibrated with data and observations. The uncertainty of the petrophysical forward function comes from uncertainty in measurements and uncertainty about the type of facies. We present a method to construct the petrophysical forward function with its associated uncertainty from the both sources above. The results show that introducing uncertainty in facies improves the accuracy of the petrophysical forward function predictions. Then, we apply the MDN inversion method to solve four different petrophysical inverse problems. In particular, we invert P- and S-wave impedance logs for the joint PDF of porosity, clay content, and water saturation using a calibrated petrophysical forward function. Results show that posterior PDF of the model parameters provides reasonable estimates of measured well logs. Errors in the posterior PDF are mainly due to errors in the petrophysical forward function. Finally, we apply the MDN inversion method to predict 3D petrophysical properties from attributes of seismic data. In this application, the inversion objective is to estimate the joint PDF of porosity, clay content, and water saturation at each point in the reservoir, from the compressional- and shear-wave-impedance obtained from the inversion of AVO seismic data. Uncertainty in the a posteriori PDF of the model parameters are due to different sources such as variations in effective pressure, bulk modulus and density of hydrocarbon, uncertainty of the petrophysical forward function, and random noise in recorded data. Results show that the standard deviations of all model parameters are reduced after inversion, which shows that the inversion process provides information about all parameters. We also applied the result of the petrophysical inversion to estimate the 3D probability maps of non-reservoir facies, brine- and oil-saturated reservoir facies. The accuracy of the predicted oil-saturated facies at the well location is good, but due to errors in the petrophysical inversion the predicted non-reservoir and brine-saturated facies are ambiguous. Although the accuracy of results may vary due to different sources of error in different applications, the fast, probabilistic method of solving non-linear inverse problems developed in this study can be applied to invert well logs and large seismic data sets for petrophysical parameters in different applications.
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Schmeide, Katja, Katharina Fritsch, Holger Lippold, Maria Poetsch, Johannes Kulenkampff, Johanna Lippmann-Pipke, Norbert Jordan, et al. "Joint project: Retention of radionuclides relevant for final disposal in natural clay rock and saline systems." Helmholtz-Zentrum Dresden - Rossendorf, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-197327.
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The objective of this project was to study the influence of increased salinities on interaction processes in the system radionuclide – organics – clay – aquifer. For this purpose, complexation, redox, sorption, and diffusion studies were performed under variation of the ionic strength (up to 4 mol/kg) and the background electrolyte.
The U(VI) complexation by propionate was studied in dependence on ionic strength (up to 4 mol/kg NaClO4) by TRLFS, ATR FT-IR spectroscopy, and DFT calculations. An influence of ionic strength on stability constants was detected, depending on the charge of the respective complexes. The conditional stability constants, determined for 1:1, 1:2, and 1:3 complexes at specific ionic strengths, were extrapolated to zero ionic strength.
The interaction of the bacteria Sporomusa sp. MT-2.99 and Paenibacillus sp. MT-2.2 cells, isolated from Opalinus Clay, with Pu was studied. The experiments can be divided into such without an electron donor where biosorption is favored and such with addition of Na-pyruvate as an electron donor stimulating also bioreduction processes. Moreover, experiments were performed to study the interactions of the halophilic archaeon Halobacterium noricense DSM-15987 with U(VI), Eu(III), and Cm(III) in 3 M NaCl solutions.
Research for improving process understanding with respect to the mobility of multivalent metals in systems containing humic matter was focused on the reversibility of elementary processes and on their interaction. Kinetic stabilization processes in the dynamics of humate complexation equilibria were quantified in isotope exchange studies. The influence of high salinity on the mobilizing potential of humic-like clay organics was systematically investigated and was described by modeling.
The sorption of Tc(VII)/Tc(IV) onto the iron(II)-containing minerals magnetite and siderite was studied by means of batch sorption experiments, ATR FT-IR and X-ray absorption spectroscopy. The strong Tc retention at these minerals could be attributed to surface-mediated reduction of Tc(VII) to Tc(IV). An influence of ionic strength was not observed.
The influence of ionic strength (up to 3 mol/kg) and background electrolyte (NaCl, CaCl2, MgCl2) on U(VI) sorption onto montmorillonite was studied. The U(VI) sorption is influenced by the background electrolyte, the influence of ionic strength is small. Surface complexation modeling was performed applying the 2SPNE SC/CE model. Surface complexation constants were determined for the NaCl and CaCl2 system and were extrapolated to zero ionic strength. Surface complexation in mixed electrolytes can be modeled applying surface complexation constants derived for pure electrolytes.
The influence of citrate on U(VI) diffusion in Opalinus Clay was studied using Opalinus Clay pore water as background electrolyte. The diffusion parameter values obtained for the HTO through-diffusion and the U(VI) in-diffusion in the absence of citric acid were in agreement with literature data. In the presence of citric acid, U(VI) diffusion was significantly retarded, which was attributed to a change in speciation, probably U(VI) was reduced to U(IV).
Larger-scale heterogeneous material effects on diffusive transport were investigated with PET. Diffusion parameters were derived by optimum fit of a FEM-model to the measurement. These parameters are in accordance with the results from 1D-through-diffusion experiments. Deviations from the simple transversal-isotropic behavior, which are identified as residuals from the model, are indications for heterogeneous transport on the mm-scale.
PET measurements were also conducted in order to display the improvement of the EDZ with waterglass injections. These experiments enable to draw conclusions on the complex reactive transport process and thus an estimation of the achieved improvement of the barrier function. The image reconstruction procedure was largely improved, mainly with the aid of Monte-Carlo simulations, and now allows quantitative analysis and error estimation.
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Valentin, Johann. "Suivi de glissements rocheux et de coulées dans les roches argileuses à partir de méthodes sismiques et photogrammétriques." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAU016/document.
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Les roches argileuses, très sensibles à la dégradation par les agents atmosphériques, se caractérisent par des mécanismes de glissement complexes, impliquant des glissements/éboulements de versants et la reprise ultérieure des matériaux argileux glissés et déstructurés par des laves torrentielles. Ce double mécanisme, très fréquent dans les Alpes, pose un problème aux responsables de l'aménagement du territoire, en raison de la soudaineté et de la dangerosité des éboulements et des laves torrentielles en cas de forte pluviométrie. Récemment, les méthodes de traitement du bruit sismique acquis en continu sur des mouvements de terrain rapides (éboulements et glissements coulées dans les sols argileux) ont montré qu'il était possible de mesurer des variations de paramètres sismiques (fréquences de résonance, vitesse de propagation des ondes S) de la zone instable. Dans deux cas d'étude (éboulement et coulée), le suivi temporel de ces paramètres à partir du bruit sismique a montré une variation significative avant le déclenchement d'un évènement gravitaire, pouvant être interprétée comme un signal précurseur. Le projet présenté vise à mettre au point une méthodologie de suivi temporel des mouvements complexes affectant les roches argileuses à partir de mesures de bruit sismique et d'acquisitions photogrammétriques. Des capteurs sismiques ont été implantés à la fois dans la zone de départ des éboulements et dans les ravines qui canalisent le matériau éboulé, afin d'étudier les variations de différents paramètres sismiques avant des instabilités de versant et le déclenchement de laves torrentielles. Ces mesures de bruit sismique ont été couplées à des campagnes d'acquisition photogrammétrique, ce qui a permis de déterminer les taux d'érosion des versants par éboulement et d'évaluer les volumes de matériaux déstabilisés susceptibles d'être affectés par des laves torrentiellesClay-rich rocks are very sensitive to weathering and are affected by complex sliding mechanisms, involving both slope sliding/falling and debris flows in a second stage. This double mechanism often occurs in the Alps and raise a problem for land managers, because of the suddenness of falls and flows. Recent studies have showed that continuous ambient vibration recordings could be used to infer seismic parameters (e.g. resonance frequency, shear wave velocity) that characterize the unstable mass. In both cases (falls and flows), the monitoring of these parameters evidences a significant variation before the triggering of gravitational movements, which has been interpreted as a precursory signal. We develop and test a monitoring methodology for such complex movements affecting clay-rich rocks, from ambient vibration measurements and photogrammetric acquisitions. We installed seismic sensors both in the scarp area and in the gullies, in which the material deposits, in order to study variations in seismic parameters before the triggering of movements. By combining these seismic measurements with regular photogrammetric acquisitions, we determine slope erosion rates and evaluate the material volumes likely to be affected by debris flows
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Yazici, Veysel. "Stabilization Of Expansive Clays Using Granulated Blast Furnace Slag (gbfs), Gbfs-lime Combinations And Gbfs Cement." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12604946/index.pdf.
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Expansive clays undergo a large swell when they are subjected
to water. Thus, expansive clay is one of the most abundant problems faced in geotechnical engineering applications. It causes heavy damages in structures, especially in water conveyance canals, lined reservoirs, highways, airport runways etc., unless appropriate measures are taken. In this thesis, Granulated Blast Furnace Slag (GBFS), GBFS - Lime combinations and GBFS Cement (GBFSC) were utilized to overcome or to limit the expansion of an artificially prepared
expansive soil sample (Sample A). GBFS and GBFSC were added to Sample A in proportions of 5 to 25 percent. Different GBFS-Lime combinations were added to Sample A by keeping the total addition at 15 percent. Effect of stabilizers on grain size distribution, Atterberg limits, swelling percentage and rate of swell of soil samples were determined. Effect of curing on swelling percentage and rate of swell of soil samples were also determined. Leachate analysis of GBFS, GBFSC and samples stabilized by 25 percent GBFS and GBFSC was
performed. Use of stabilizers successfully decreased the amount of swell while increasing the rate of swell. Curing samples for 7 and 28 days resulted in less swell percentages and higher rate of swell.
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Muñoz, Juan Jorge. "Thermo-hydro-mechanical analysis of soft rock. Application to a large scale heating test and large scale ventilation test." Doctoral thesis, Universitat Politècnica de Catalunya, 2007. http://hdl.handle.net/10803/6244.
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Esta Tesis está dirigida al análisis teórico y experimental de problemas acoplados Termo-Hidro Mecánico (THM) que se desarrollan en formaciones geológicas profundas destinadas al almacenamiento de residuos radiactivos de alta actividad. En las últimas décadas, han sido estudiadas las formaciones arcillosas para ser utilizadas como barreras geológicas debido a su reducida conductividad hidráulica. La degradación de las rocas arcillosas producida por efectos de temperatura y por efectos de variación en el grado de saturación, es un factor de fundamental importancia, que es actualmente investigado en ensayos in situ a gran escala, como así también en ensayos de laboratorio.En ésta tesis, la roca Opalinus Clay ha sido ampliamente caracterizada mediante ensayos de laboratorios. Desde un punto de vista macro-estructural se ha obtenido la curva de retención de agua, conductividad hidráulica, resistencia y deformación. El análisis micro-estructural está enfocado a la caracterización mineralógica obtenida por difracción de rayos X, la distribución del tamaño de los poros determinada por porosimetría de mercurio (MIP) y microscopía electrónica (SEM).
La tesis describe también un ensayo in situ de calentamiento diseñado para analizar la interacción entre la barrera de ingeniería (bloques de bentonita compactada) y la barrera geológica (Opalinus clay). Esta interacción ha sido analizada a través de simulaciones numéricas realizadas con el código de elementos finitos CODE_BRIGHT. Una célula termo-hidráulica fue especialmente diseñada para observar el comportamiento THM de la roca en condición drenada y no drenada, a través de pulsos de calor. Parámetros térmicos e hidráulicos de la roca fueron determinados por retro análisis a través de simulaciones numéricas realizadas con CODE_BRIGHT.
Desde el punto de vista mecánico, un modelo constitutivo ha sido formulado en 3D e implementado en CODE_BRIGHT con el objetivo de reproducir el comportamiento mecánico anisótropo y rotura frágil de las rocas arcillosas. El modelo es formulado en un marco viscoplástico y considera la resistencia y deformabilidad de la matriz y de las juntas. El criterio de falla de la matriz y de las juntas es definido por superficies de fluencias hiperbólicas en el espacio de tensiones p-J y τ−σ, respectivamente. El comportamiento frágil de las rocas arcillosas es simulado por un reblandecimiento isótropo y cinemático definido en términos de trabajo de deformación plástico. El modelo constitutivo ha sido calibrado mediante ensayos triaxiales de laboratorio realizados en especimenes con diferentes ángulos de buzamiento. El modeloconstitutivo anisótropo ha sido aplicado a la simulación numérica en 3D de un ensayo de calentamiento in-situ. Una simulación numérica en 3D de un ensayo de ventilación in-situ realizado en un micro-túnel sin recubrimiento ha sido realizada para reproducir el brusco cambio de permeabilidad por efectos de secado de la roca. En este caso, un modelo hidráulico que considera la apertura de las juntas por efectos de secado ha sido implementado para reproducir los cambios de permeabilidad en excavaciones subterráneas.
This thesis deals with the theoretical and experimental analysis of the coupled Thermo- Hydro-Mechanical (THM) processes developed in geological formations suitable for the repository of radioactive waste of high activity. In the last decades, the argillaceous formations have been studied to be used as geological barriers, due to its reduced hydraulic conductivity. The degradation of clay shales induced by temperature and saturation effects is an important factor which is currently being investigated in large scale in situ tests as well as in laboratory studies. In this thesis, the Opalinus clay rock has been widely characterized by means of laboratory tests.
From a macro-structural point of view, the water retention curve, hydraulic conductivity, strength and deformability parameters have been determined. The micro-structural analysis is focused to the mineralogical characterization obtained by means of X ray diffraction, pore size distribution (PSD) determined by means of mercury intrusion porosimetry (MIP) and scanning electronic microscopy (SEM).
The thesis describes also a large scale heating in situ test designed to analyze the interaction between the engineer barrier (compacted bentonite blocks) and by the geological barrier, (Opalinus clay). This interaction has been analyzed by means of numerical simulations performed with the finite element code CODE_BRIGHT. A thermo hydraulic cell was specially designed to observe the coupled THM behaviour of the clay shale rock under drained and undrained conditions by means of heat pulses. Thermal and hydraulic parameters of rock were determined by means of back-analysis performed with the help of CODE_BRIGHT. In order to reproduce the anisotropic and brittle behaviour of the clay shale, a 3D mechanical constitutive model has been formulated and implemented in CODE_BRIGHT.
The constitutive model is formulated in a viscoplastic framework and it considers the strength and deformability of both matrix and discontinuities (joints). The failure criterion of the matrix and the joints is defined by means of hyperbolic yield surfaces in the p-J and τ-σ stress space, respectively. The brittle behaviour of clay shale is simulated by means of isotropic and kinematic softening defined in terms of a workhardening criterion. The anisotropic constitutive model has been calibrated against triaxial laboratory tests performed on specimens with a main family of discontinuities having different dip angles. The constitutive model has been applied to a 3D numerical simulation of an "in-situ" heating test. A 3D numerical simulation of a ventilation test performed in an unlined micro tunnel was also performed in order to reproduce the changes of the rock permeability by drying effects. In this case, a hydraulic model able to consider the changes in joint thickness by drying effects has been developed to reproduce the changes of permeability in underground excavations.
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Dantas, Ant?nio de P?dua Arlindo. "Utiliza??o de res?duos de rochas ornamentais na produ??o de cer?mica branca." Universidade Federal do Rio Grande do Norte, 2009. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15554.
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Previous issue date: 2009-10-06The marble and granite waste come from the process of mining of those ornamental rocks for use in the building industry. Brazil is one of the largest producers of blocks or finished products of ornamental rocks, extracting about 5.2 tons / year. The largest national producers are the states of Esp?rito Santo, Minas Gerais and Bahia which account for 80% of the Brazilian production. However, the waste total amount during processing of these blocks reaches 40% of the total. The use of the waste produced by this industry in white ceramics could be a form of disposition, because these materials, are thrownasa mud directly at decantation ponds, wastelands or in rivers, without any treatment. The present work has as main purpose to study the influence that reject of the ornamental rocks on the physical and mechanical properties of white ceramics. X-Ray characterizations of raw materials by were performed X-Ray fluorescence, X-Ray diffraction, granulometric, thermogravimetric and thermodiferencial analysis, five formulations were made (0, 10, 20, 30, 40% in granite weight) wich were burned at three temperatures: 1100?C, 1150?C and 1200?C with 60 minutes of sorling time. After sintering, the samples were submitted to different analyser absorption of water, linear retraction, apparent porosity, apparent specific mass, flexival stronght, and scanning were obtained microscopy. Compatible technological properties within the limits demanded for the production of porcelainized stoneware
Os rejeitos de granito s?o provenientes do processo de minera??o dessas rochas ornamentais para uso na ind?stria da constru??o civil. O Brasil ? um dos maiores produtores de blocos ou produtos acabados de rochas ornamentais, extraindo cerca de 5,2 milh?es toneladas/ano. Os maiores produtores nacionais s?o os estados do Esp?rito Santo, Minas Gerais e Bahia que respondem por 80% da produ??o nacional. Por?m o desperd?cio em todo o processo de desmonte destes blocos chega a incr?veis 40% do total. O uso dos detritos produzidos por esta ind?stria na cer?mica branca poderia ser uma forma de disposi??o desse material, visto que estes materiais, sob forma de lama, s?o lan?ados diretamente em lagoas de decanta??o, terrenos baldios ou jogados em rios, sem nenhum tratamento. O presente trabalho tem como prop?sito principal estudar a influ?ncia que o rejeito das rochas ornamentais exerce sobre as propriedades f?sicas e mec?nicas da cer?mica branca. Para isso, foram feitas as caracteriza??es das mat?rias-primas por fluoresc?ncia de Raios-X, difra??o de Raios-X, an?lise granulom?trica, an?lise termogravim?trica e an?lise termodiferencial, elaborando-se cinco formula??es (0, 10, 20, 30, 40% em peso de granito) que foram queimadas em tr?s temperaturas: 1100?C, 1150?C e 1200?C com 60 minutos de patamar. Ap?s a queima, os corpos-de-prova foram submetidos a ensaios de absor??o de ?gua, retra??o linear, porosidade aparente, massa espec?fica aparente, resist?ncia ? flex?o, microscopia eletr?nica de varredura. Foram obtidas propriedades tecnol?gicas compat?veis com os limites m?nimos exigidos para a fabrica??o de um gr?s porcelanato
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Gautam, Tej P. "An Investigation of Disintegration Behavior of Mudrocks Based on Laboratory and Field Tests." Kent State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=kent1352922708.
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Ispir, Mustafa Erdem. "A Laboratory Study Of Anisotropy In Engineering Properties Of Ankara Clay." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613779/index.pdf.
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Anisotropy in engineering properties of soils occurs due to the depositional process forming the soil fabric and/or different directional stresses in soil history. This study investigates the anisotropy in undrained shear strength and drained compressibility of preconsolidated, stiff and fissured Ankara Clay. The compressibility behavior is determined using standard oedometer testing while the shear strength anisotropy is investigated through large diameter unconsolidated-undrained triaxial testing on undisturbed samples taken in vertical and horizontal directions from several deep excavation sites along the Konya Road in Çukurambar-Balgat Area, Ankara. According to the results achieved, Ankara Clay is slightly anisotropic in compressibility, with an anisotropy ratio between 0.72 and 1.17 in terms of coefficient of volume compressibility for several pressure ranges between 50 kPa and 1600 kPa. On the other hand, while a slight anisotropy in undrained shear strength at a ratio ranging between 0.87 and 1.19 in terms of deviator stress can be observed in Ankara Clay, considering the great variation in the test results of samples in same direction which mostly overlaps with the range of results obtained in the other direction, it has been concluded that the Ankara Clay located in this area can be regarded as isotropic in terms of shear strength for practical purposes.
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Schmeide, Katja, and Gert Bernhard. "Joint Project: Interaction and transport of actinides in natural clay rock with consideration of humic substances and clay organics - Characterization and quantification of the influence of clay organics on the interaction and diffusion of uranium and americium in the clay." Helmholtz-Zentrum Dresden-Rossendorf, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-85396.
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The objective of this project was the study of basic interaction processes in the systems actinide - clay organics - aquifer and actinide - natural clay - clay organics - aquifer. Thus, complexation, redox, sorption and diffusion studies were performed.
To evaluate the influence of nitrogen, phosphorus and sulfur containing functional groups of humic acid (HA) on the complexation of actinides in comparison to carboxylic groups, the Am(III) and U(VI) complexation by model ligands was studied by UV-Vis spectroscopy and TRLFS. The results show that Am(III) is mainly coordinated via carboxylic groups, however, probably stabilized by nitrogen groups. The U(VI) complexation is dominated by carboxylic groups, whereas nitrogen and sulfur containing groups play a minor role. Phosphorus containing groups may contribute to the U(VI) complexation by HA, however, due to their low concentration in HA they play only a subordinate role compared to carboxylic groups. Applying synthetic HA with varying sulfur contents (0 to 6.9 wt.%), the role of sulfur functionalities of HA for the U(VI) complexation and Np(V) reduction was studied. The results have shown that sulfur functionalities can be involved in U(VI) humate complexation and act as redox-active sites in HA for the Np(V) reduction. However, due to the low content of sulfur in natural HA, its influence is less pronounced.
In the presence of carbonate, the U(VI) complexation by HA was studied in the alkaline pH range by means of cryo-TRLFS (-120°C) and ATR FT-IR spectroscopy. The formation of the ternary UO2(CO3)2HA(II)4− complex was detected. The complex formation constant was determined with log β0.1 M = 24.57 ± 0.17.
For aqueous U(VI) citrate and oxalate species, luminescence emission properties were determined by cryo-TRLFS and used to determine stability constants. The existing data base could be validated.
The U(VI) complexation by lactate, studied in the temperature range 7 to 65°C, was found to be endothermic and entropy-driven. In contrast, the complex stability constants determined for U(VI) humate complexation at 20 and 40°C are comparable, however, decrease at 60°C.
For aqueous U(IV) citrate, succinate, mandelate and glycolate species stability constants were determined. These ligands, especially citrate, increase solubility and mobility of U(IV) in solution due to complexation.
The U(VI) sorption onto crushed Opalinus Clay (OPA, Mont Terri, Switzerland) was studied in the absence and presence of HA or low molecular weight organic acids, in dependence on temperature and CO2 presence using OPA pore water as background electrolyte. Distribution coefficients (Kd) were determined for the sorption of U(VI) and HA onto OPA with (0.0222 ± 0.0004) m3/kg and (0.129 ± 0.006) m3/kg, respectively. The U(VI) sorption is not influenced by HA (50 mg/L), however, decreased by low molecular weight organic acids (> 1×10-5 M), especially by citrate and tartrate. With increasing temperature, the U(VI) sorption increases both in the absence and in the presence of clay organics.
The U(VI) diffusion in compacted OPA is not influenced by HA at 25 and 60°C. Predictions of the U(VI) diffusion show that an increase of the temperature to 60°C does not accelerate the migration of U(VI). With regard to uranium-containing waste, it is concluded that OPA is suitable as host rock for a future nuclear waste repository since OPA has a good retardation potential for U(VI).
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Engin, Kursat Harun. "An Experimental Study Of Vertical And Inclined Soil Nails Under Footings As Settlement Reducers." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12605775/index.pdf.
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Vertical and inclined soil nails under footings as settlement &ndashreducing elements is investigated using a physical 1g model in the laboratory. Nails are not connected to footing, they are not so long and vertical settlement of nails is very large compared to usual limits encountered for piles or micropiles. Following the settlement of footing, they share the load together with the footing. The skin friction is mostly mobilized and end-bearing failure occurs continuously during the settlement. The system of footing- soil nail is studied by model square footings of 30 mm x 30 mm and 50 mm x 50 mm breadth dimensions and remoulded kaolin clay consolidated under constant controlled stress of 50 kPa in 200 mm cube boxes. In the first section of the testing series 4, 5, 9 and 12 nails were inserted into soil in 3B, 2.4B, 1.33B and B lengths, respectively. In the second section, 4 and 6 nails in 1.5B and 2B lengths were tested for vertical and 15 degrees and 30 degrees inclined cases. Settlements of footings were measured under constant footing pressure for all groups. Several tests were repeated in each group of testing series. It is concluded that keeping the total nail length constant, decreasing the nail number thus using longer individual nails is more effective in decreasing the footing settlements. 15 degrees inclined nails decrease total settlements more.
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Lundberg, Emil. "2D and 3D Reflection Seismic Studies over Scandinavian Deformation Zones." Doctoral thesis, Uppsala universitet, Geofysik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-211215.
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The study of deformation zones is of great geological interest since these zones can separate rocks with different characteristics. The geometry of these structures with depth is important for interpreting the geological history of an area. Paper I to III present 2D reflection seismic data over deformation zones targeting structures in the upper 3-4 km of the crust. These seismic profiles were acquired with a crooked-line recording geometry. 2D seismic processing assumes a straight recording geometry. Most seismic processing tools were developed for sub-horizontally layered structures. However, in the crystalline rocks in Scandinavia more complex structures with contrasting dip directions and folding are common. The crooked-line recording geometries have the benefit of sampling a 3D volume. This broader sampling can be used to gain knowledge about the true geometry of subsurface structures. Correlation with geological maps and other geophysical data along with seismic data modeling can be used to differentiate reflections from faults or fracture zones from other reflectivity, e.g. mafic bodies. Fault and fracture zones may have a large impedance contrast to surrounding rocks, while ductile shear zones usually do not. The ductile shear zones can instead be interpreted based on differing reflectivity patterns between domains and correlations with geology or magnetic maps. Paper IV presents 3D reflection seismic data from a quick-clay landslide site in southern Sweden. The area is located in a deformation zone and structures in unconsolidated sediments may have been influenced by faults in the bedrock. The main target layer is located at only 20 m depth, but good surface conditions during acquisition and careful processing enabled a clear seismic image of this shallow layer to be obtained.The research presented in this thesis provides increased knowledge about subsurface structures in four geologically important areas. The unconventional processing methods used are recommended to future researchers working with data from crooked-line recording geometries in crystalline environments. The imaging of shallow structures at the quick-clay landslide site shows that the 3D reflection seismic method can be used as a complement to other geophysical measurements for shallow landslide site investigations.
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Stavropoulou, Eleni. "Comportement différé des interfaces argilite/béton : caractérisation et modélisation." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAI077/document.
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La gestion des déchets radioactifs est une question environnementale importante, en particulier dans les pays où l'énergie nucléaire est générée. L'Andra (Agence Nationale pour la gestion des Déchets RAdioactifs) étudie la solution d'un stockage géologique profond dans un couche d'argilite Callovo Oxfordienne (COx). L'étanchéité des galeries souterraines est partiellement assurée par une barrière mécanique en béton qui est directement en contact avec l'argilite. Tels projets nécessitent une prédiction de déformations irréversibles dans le temps sur une grande échelle, afin d'évaluer la durabilité de l'accouchement. Même si les propriétés physiques de la plupart des matériaux impliqués (argilite et béton par exemple) sont maintenant raisonnablement connues, ils existent que quelques études sur le comportement des interfaces de contact entre ces matériaux. Ce sujet est d'une grande importance pour prédire une durée de vie provisoire des installations de stockage de déchets nucléaires.Au cours de cette thèse, le comportement mécanique de l'interface argilite / béton a été étudié. Le Callovo Oxfordian est considéré comme une barrière géologique idéale grâce à sa très faible perméabilité. Cependant, son comportement est gouverné par un couplage thermo-hydro-mécanique de haute complexité, qui est en cours d'investigation avec des expériences en laboratoire et textit{in-situ}. Avec la préparation des échantillons d'interface, une étude courte sur l'absorption d'eau liquide dans la non-confinée argilite, a été réalisée. Afin de caractériser le comportement à court terme de l'interface, plusieurs essais de cisaillement direct ont été effectués sous différentes conditions limites, en utilisant le dispositif expérimental BCR-3D situé dans 3SR.Pour l'étude du comportement mécanique à long terme de l'interface, la conception et développement d'un nouvel appareil expérimental. Une des parties les plus importantes de ce travail, comprend la conception et le développement de SInC Box - Shearing Interfaces Creep Box - un dispositif original pour l'étude des déformations différées des interfaces. Plusieurs essais de fluage ont été effectués sur des éprouvettes d'interface, permettant d'étudier le comportement différé de l'interface en cisaillement. Le comportement mécanique post-fluage de l'interface argilite / béton a également été exploité. Les résultats expérimentaux de la réponse différé ont également été analysés selon des modèles analytiques viscoélastiques et simulations numériquesThe management of radioactive waste is an important environmental issue, in particular in the countries where nuclear power is generated. In Eastern France, The French National Radioactive Waste Management Agency (ANDRA) is investigating the behaviour of a deep geological repository in Callovo Oxfordian clay-rock (COx). The sealing of the underground repository tunnel, is partly ensured by a mechanical barrier made of concrete, directly in contact with the rock. Such projects require prediction of irreversible deformations over a large time scale, in order to assess the durability of the confinement. Even though the physical properties of most of the materials involved (rock and concrete for example) are now reasonably known, there have been only a few studies of the behaviour of the contact interfaces between these materials. This subject is of great importance for predicting a tentative life-time of nuclear waste storage facilities.During this PhD work the mechanical behaviour of the clay-rock/concrete interface has been investigated. The Callovo Oxfordian is considered as an ideal geological barrier because of its extremely low permeability. However, it is governed by a thermo-hydro-mechanical behaviour of high complexity, which is continuously under investigation with both laboratory and in-field experiments. The preparation of the interface samples involved a short study on the liquid water uptake in the unconfined clay-rock. In order to characterise the short-term behaviour of the interface, direct shear tests have been performed under different boundary conditions, using the BCR3D experimental device located in 3SR.The investigation of the long-term mechanical behaviour of the interface required the design of a new experimental apparatus. One of the most important parts of this study includes the conception and development of SInC Box -- Shearing Interfaces Creep Box -- an original device for the study of delayed deformations of interfaces. Different sets of creep tests have been performed on the interface samples allowing the investigation of the interface's delayed behaviour in shear. The post-creep mechanical behaviour of the clay-rock/concrete interface has also been exploited exhibiting great interest. The experimental results of the delayed response have been further analysed using analytical visco-elastic models and numerical simulations
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Rivard, Camille. "Contribution à l'étude de la stabilité des minéraux constitutifs de l'argilité du Callovo-Oxfordien en présence de fer à 90° C." Thesis, Vandoeuvre-les-Nancy, INPL, 2011. http://www.theses.fr/2011INPL090N/document.
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Dans le contexte de stockage des déchets radioactifs en profondeur, des interactions entre le fer métal d’une part et la roche du Callovo-Oxfordien (COx), sa fraction argileuse purifiée (SCOx) ou des phases argileuses pures (kaolinite, illite, smectites) d’autre part, sont réalisées à 90°C sous atmosphère anoxique en solution chlorurée-salée. Le rôle des minéraux non argileux du COx est également étudié. L'oxydation rapide du fer métal entraine une libération d’ions fer en solution, une augmentation du pH et une diminution du Eh (réducteur). Une dissolution partielle des phases argileuses ainsi que la précipitation de serpentines ferrifères (odinite ou berthiérine, principalement) et de magnétite en faible quantité sont alors observées. En cas d’apport d'O2 au système, les serpentines ferrifères sont déstabilisées. L'exsolution du fer permet la formation d'oxydes et d’hydroxydes de fer et des particules argileuses proches des phases initiales précipitent. Lorsque du quartz est ajouté à SCOx, la dissolution partielle de ce minéral est responsable de la modification des chemins réactionnels. La formation de magnétite est alors limitée et les serpentines ferrifères sont enrichies en silice. Dans le cas de la kaolinite, DRX, MET, XPS et analyses texturales mettent en évidence la croissance des serpentines ferrifères (berthierines majoritairement) sur la surface basale des kaolinites, formant des particules kaolinite-serpentines-Fe démixées. Les techniques spectroscopiques (Mössbauer, XAS et STXM) permettent de déterminer les rapports Fe2+/Fe3+ et AlIV/AlVI jusqu'au niveau des particules élémentaires et de proposer des formules structurales pour ces serpentines ferrifèresIn the context of underground disposal of high-level radioactive waste, interactions between metallic iron and Callovo-Oxfordian rock (COx), its purified clay fraction (SCOx) or pure clay phases (kaolinite, illite, smectites) were investigated at 90°C under anoxic atmosphere in chlorine solution. Role of COx non clay minerals in these reactions was also studied. Rapid metallic iron oxidation conducts to iron cations release in solution, pH increase (8-10) and Eh decrease (reducive conditions). The partial dissolution of initial clay phases and the crystallization of Fe-serpentines (odinite or berthierine mainly) and of low amount of magnetite were observed. The introduction of O2 into the system leads to Fe-serpentines destabilisation. Iron exsolution conducts to iron oxides and hydroxides formation and clay particles with composition close to the initial ones precipitate. Addition of quartz into the system leads to the partial dissolution of this mineral and to the modification of reaction pathways. Precipitation of magnetite is reduiced and Fe-serpentines are silica enriched. In the case of kaolinite-metallic iron interaction, combinated used of XRD, MET, XPS and textural analyses evidences the growth of berthierine on the basal face of kaolinites, resulting in Fe-serpentine-kaolinite demixed particles. Through the used of spectroscopic analyses (Mössbauer, XAS and STXM), we were able to determine Fe2+/Fe3+ and AlIV/AlVI ratio in elementary particles, which allows proposing structural formulae for the Fe-serpentines
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Fauchille, Anne-Laure. "Déterminismes microstructuraux et minéralogiques de la fissuration induite par dessiccation dans les argilites de Tournemire : apports couplés de la pétrographie quantitative et de la corrélation d'images numériques." Thesis, Poitiers, 2015. http://www.theses.fr/2015POIT2252/document.
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Ce travail de thèse s’est inséré dans la problématique du stockage de déchets radioactifs en formation argileuse profonde. Il porte en particulier sur l’étude de la fissuration hydrique induite par la désaturation et resaturation de la roche en paroi des galeries de la station expérimentale de Tournemire (Averyon, France). Cette étude a visé à identifier les déterminismes microstructuraux et minéralogiques de la fissuration hydrique des argilites de Tournemire, en couplant au laboratoire la Corrélation d’Images Numériques (CIN) et la Microscopie Electronique à Balayage (MEB). Deux échantillons d’argilite de Tournemire ont été soumis à des variations d’humidités différentes par chocs et par paliers progressifs. La CIN a permis de mettre en évidence l’influence de l’humidité et de la teneur en eau sur l’amplitude de l’ouverture des fissures et des déformations à différentes échelles. Cette étude a également permis de mettre en lumière l’influence du chargement hydrique sur l’organisation des réseaux de fractures. Une cartographie minéralogique sur un champ plurimillimétrique en haute résolution a été également mise en œuvre au MEB sur ces deux échantillons d’argilites. Cette cartographie a permis d’apporter des données qualitatives et quantitatives sur l’anisotropie microstructurale et minéralogique de la roche argileuse et de proposer une estimation de la surface élémentaire représentative du système grain/matrice pour des zones à tendance argileuse.Le couplage de la CIN avec le MEB a révélé l’importance des hétérogénéités microstructurales relatives à la proportion, taille, élongation et orientation moyennes des inclusions rigides présentes dans la matrice argileuse de la roche, sur la localisation des fissures hydriquesThis study is included in the issues of a nuclear waste storage in deep geological clay formations. It concerns the cracking phenomenon due to desaturation and saturation processes of the argillaceous medium on gallery walls of the Underground Laboratory of Tournemire (Aveyron, France). The work presented here aims to identify in laboratory the different mineralogical factors which control the cracking generated by humidity variations, coupling two methods: the Digital Image Correlation (DIC) and the Scanning Electron Microscopy (SEM).Two clay rock samples were submitted to swelling/shrinkage processes by fast bumps or gradual humidity variations. The DIC method enabled to reveal the influence of humidity and water content on crack widths and deformations intensity to different scales. This study highlighted the part of humidity variations on evolution and width of crack networks while comparing the results obtained by different conditions of humidity variations.A mineralogical map was investigated on a millimeter field with high resolution on two clay rock samples. It allowed to: quantify the microstructural anisotropy of the rock, and estimate the size of a representative elementary surface of a microstructural system composed of coarse grains and clay matrix, for argillaceous areas.The DIC-SEM approach has shown the closed relation between the location of microstructural heterogeneities such as local proportion of coarse grains and clay matrix, medium size, length ratio and orientation of coarse grains, with the position of the hydric cracks
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Faivre, Pierre. "Lessivage et planosolisation dans les séquences de sols caractéristiques des milieux intrandins de Colombie (Amérique du sud)." Nancy 1, 1988. http://www.theses.fr/1988NAN1A002.
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Étude des couvertures pédologiques complexes des versants des dépressions andines qui sont organisées en climatoséquences et développées à partir de pyroclastiques. On retrouve des andosols, des ferrisols (sombritropepts, sombrihumults), brunizem (argiudolls, arguistolls) et des planosols (haplustalfs, naturstafs). Tout le long du profil le cortège argileux est constitué d'halloysite. Les facteurs intensifiant le lessivage vers l'aval sont étudiés. Dans les couvertures anciennes des caractères polygénétiques sont décelables dans certains profils de planosols. Une étude des isotopes stables du carbone permet d'établir le sens des variations paléoécologiques et paléoclimatologiques
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Гоптарьова, Н. В. "Геолого-фізичні чинники деформаційних процесів породних масивів і експлуатаційних колон свердловин нафтогазових родовищ внутрішньої зони Передкарпатського прогину." Thesis, Івано-Франківський національний технічний університет нафти і газу, 2003. http://elar.nung.edu.ua/handle/123456789/3980.
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Дисертація присвячена вивченню геолого-фізичних чинників, що впливають на деформаційні процеси породних масивів та на технічний стан експлуатаційних колон свердловин нафтогазових родовищ Внутрішньої зони Передкарпатського прогину. За результатами геолого-промислового матеріалу побудовано карти-схеми геотехногенної порушеності родовищ і визначено зони активізації деформаційних процесів, які відрізняються інтенсивністю проявів тектонічних рухів та деформацій осадових товщ. Побудовано графічні та встановлено аналітичні залежності зміни пористості гірських порід від зміни пластового тиску. Встановлено, що виникнення деформацій і зсувів масиву гірських порід пов’язано із зниженням пластового тиску в процесі розробки родовищ та із зміною термогідродинамічних параметрів у покладах. Побудовано графіки розподілу напруг зсуву з віддаленням від зони дренажу свердловини у межах родовищ та показано зміну вологості глинистих порід в залежності від пластової температури і розподіл її в пристовбурній зоні. Запропоновано ряд заходів щодо уникнення порушення експлуатаційних колон свердловин з метою підвищення ефективності доопошукування, дорозвідки та дорозробки нафтогазових родовищ.На основании анализа промышленных характеристик буровых скважин, многочисленных геолого-геофизических и литературных материалов, а также соответствующих фактических данных для Долинского, Северодолинского, Оров-Уличнянского и Битков-Бабченского месторождений установлено, что в пределах месторождений существуют отдельные зоны активизации деформационных процессов, которые отличаются литолого-фациальными особенностями пород, интенсивностью проявлений тектонических движений, обусловленных геодинамическими и термогидродинамическими процессами. Построены карты-схемы геотехногенного нарушения месторождений, которые разрешают выявить закономерности смятия обсадных колон скважин в зависимости от геологического строения месторождений. Нарушение эксплуатационных колонн буровых скважин и соответственно снижение добычи нефти и газа есть следствием активизации деформационных процессов, вызванных геодинамическими и термогидродинамическими изменениями в залежах в период разработки месторождений. Из вышесказанного вытекают соответствующие предложения относительно закладывания эксплуатационных буровых скважин с целью увеличения термина их работы, которые имеют большое практическое значение.
The dissertation is devoted to study of the geology-physical factors, which influence on a deformation processes of rocks and a technical condition of operational columns of wells in oil and gas fields of an Internal zone of the Precarpathian deflection. By results of a geology-industrial material the maps-schemes of geotekhnogenic break of fields are constructed and is determined zones of activization of deformation processes, which differ by intensity of displays of tectonic movements and deformations of rocks. Are constructed graphic and the analytical dependencies of change rock’s porosity from change of pressure are established. Is established, that the occurrence of deformations and shifts of rocks is connected to decrease of pressure during development of deposits and with change of a thermohydrodinamic processes in deposits. The diagram of distribution of pressure of shift with a distance from deposits is constructed within the limits of deposits and the change of humidity of clay rocks is shown graphically depending of temperature and distribution it into a well zone. A number of measures on avoidance of infringement of operational columns of wells is offered with the purpose of increase of efficiency of searches, investigation and development of oil and gas fields.
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Mathis, Benoît. "Diagraphies et sédimentologie : traduction du message diagraphique et reconnaissance des systèmes sédimentaires : exemples des faciès hypersiliceux paléogènes et crétacés de l'offshore gabonais." Nancy 1, 1988. http://www.theses.fr/1988NAN10184.
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Après un rappel des différents types de diagraphies existants et leur méthode d'interprétation, on présente des systèmes d'analyse et de tracé de courbes automatiques. Plusieurs programmes automatiques d'étude des faciès et des séquences sédimentaires sont mentionnés. Puis, on applique ces méthodes au cas des faciès hypersiliceux de l'ouzouri et de l'anguille : opalite, chert, grès, silt et argiles siliceux, carbonates siliceux et argiles opalifères. On montre l'intérêt des diagraphies dans la détermination de la qualité des réservoirs potentiels. L'organisation spatio-temporelle des dépôts gabonais est caractéristique d'une mégaséquence d'ouverture océanique
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Moulin, Gérard. "Etat limite d'une argile naturelle : l'argile de pornic." Nantes, 1988. http://www.theses.fr/1988NANT2028.
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Description d'une naturelle, l'argile de pornic, suivant les concepts d'etat limite et d'etat critique. On realise une serie d'essais triaxiaux axisymetriques sur argile consolidee et on met en evidence la courbe d'etat limite du materiau, intersection de la surface d'etat limite et de la surface dite "d'etat surconsolide". La representation des chemins contraintes-deformations dans un diagramme original ou dans le diagramme normalise permet de cartacteriser leur reciprocite et de suivre leur evolution au passage de la courbe d'etat limite. L'etude de l'influence du temps ou de la vitesse de deformation demontre que les enveloppes de fluage se contractent dans l'espace des contraibntes quand le temps augmente et qu'une unique fait defaut pour caracteriser reciproquement les chemins de contraintes draines et non-draines en fonction des vitesses de sollicitations
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Ktari, Mohamed. "Contribution à la détermination des caractéristiques mécaniques des sols aux faibles déformations en régime dynamique." Paris 6, 1986. http://www.theses.fr/1986PA066512.
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Ben, Ohoud Mohsine. "Etude comparative de l'organisation des materiaux argileux en termes de dimensions fractales." Orléans, 1988. http://www.theses.fr/1988ORLE2002.
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Caracterisation structurale et texturale des materiaux argileux selon une nouvelle approche reposant sur l'idee que l'organisation des elements de la texture a une echelle donnee se retrouve adaptes a chaque echelle. Formalisation de cette approche dans le cadre de la theorie des fractals. On montre aue kaolinite, argiles fibreuses et illite relevent d'une description triviale, basee sur un assemblage tridimensionnel desordonne, alors que les montmorillonites sont des materiaux a texture fractale. On analyse les correlations entre dimensions fractales de surface et de porosite des montmorillonitesm deshydratees et les proprietes des suspensions (permeabilite, retention en eaum rheologie)
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Koksalan, Ali Okan. "A Preliminary Study On Construction Of A High Capacity Tensiometer And Its Use In Measurement Of Matric Suction In Unsaturated Soils." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615637/index.pdf.
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Soil suction is one of the main state parameters that governs unsaturated soil behaviour. Tensiometers are the only type of probe that can measure soil suction directly, but only up to 90 kPa. In the past two decades, a new type of tensiometer with much greater measurement range (up to 2 MPa) has appeared in the literature. The measurement range (i.e. capacity) of a tensiometer is limited by (i) how well it is saturated, and (ii) the air entry value of its porous interface.
In this study, the first high capacity tensiometer of Turkey was designed and built. For the purpose of increasing the measurement capacity of the tensiometers, a novel saturation setup that uses a hydraulic pressurization system with capacity of 10 MPa was designed and built. A vacuum-and-pressure saturation procedure was developed. To calibrate the 10 MPa pressure transducers that form the core of the tensiometers, a high-pressure calibration setup capable of pressurizing up to 11 MPa was designed and built. By varying designs of tensiometer bodies, porous interfaces and seals, ways of increasing the suction capacity are investigated. Over a dozen tensiometer design variations are developed, and tried by exposing to atmospheric evaporation. A maximum suction measurement of 870 kPa was achieved with a conventional designhowever, none of the new designs were successful. 3 successful designs were also briefly tried on soil samples
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Godon, Nicole. "Effet des materiaux d'environnement sur l'alteration du verre nucleaire r7t7 : influence des argiles." Orléans, 1988. http://www.theses.fr/1988ORLE2045.
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On a entrepris des essais comparatifs sur differents materiaux argileux et on a suivi la cinetique de l'interaction eau/verre/materiau pendant 1 an. La presence d'argile a ete correlee avec la vitesse de corrosion du verre nucleaire et on a recherche le meilleur materiau pour elaborer des barrieres ouvragees empechant cette alteration
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CAPELLE, THIERRY. "Penetration libre dans les sediments marins : etude du comportement dynamique et rheologique d'une argile reconstituee." Toulouse 3, 1988. http://www.theses.fr/1988TOU30045.
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Etude de la penetration libre dans les sediments marins afin d'en evaluer les capacites de resistance au cisaillement ou pour determiner des profondeurs d'enfouissement maximales. Les phenomenes limitant l'enfouissement sont du a la portance et au frottement. On determine les proprietes rheologiques et dynamique de l'argile a partir d'une serie de tirs de projectiles effectues en fosse d'essais. L'etude du decelerogramme d'essai distingue les phases ou le comportement du sol au contact du penetreur varie depuis l'hydrodynamique jusqu'a la visco-plasticite
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Clement, Corinne. "Etude de coulis hydrauliques pour la retention des cations polluants pb, cd, hg, sr, cs." Paris, ENMP, 1988. http://www.theses.fr/1988ENMP0091.
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BEAREZ, CHRISTINE. "Transformation catalytique de composés représentatifs de la matière organique sédimentaire sur minéraux naturels et synthétiques." Poitiers, 1985. http://www.theses.fr/1985POIT2022.
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Influence catalytique des mineraux naturels sur l'evolution de composes naturels importants: le cholesterol et l'acide stearique. Les transformations de ces composes ont ete etudiees sur diverses roches: argiles, calcite, dolomite et anhydrite et sur des catalyseurs connus dans des conditions aussi representatives que possible du milieu naturel. Quel que soit le solide considere la transformation catalytique est beaucoup plus rapide que la reaction thermique
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Vu-Do, Laurence. "Influence de la matière organique naturelle mobile sur la rétention de l’europium sur l’argilite de Bure." Thesis, Paris 11, 2013. http://www.theses.fr/2013PA112022/document.
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Dans le contexte du stockage profond des déchets radioactifs de haute et moyenne activité à vie longue en France, l’argilite de Bure (Arg) a été choisie comme roche hôte notamment pour ses propriétés de rétention des radionucléides. Or, cette roche argileuse dite du Callovo-Oxfordien (COx) contient naturellement de la matière organique (MO). Le but de cette thèse est d’évaluer l’influence de la MO naturelle mobile sur la rétention sur l’argilite de l’europium, analogue classique des actinides trivalents des déchets vitrifiés. Trois molécules organiques sont étudiées : les acides subérique, sorbique et tiglique, acides organiques de faible poids moléculaire identifiés dans l’eau porale naturelle du COx. Toutes les expériences ont été réalisées dans un milieu simulant l’eau du COx (pH=7,5 ; I=0,1 mol/L ; PCO2 =10^(-2) bar).La caractérisation de notre échantillon d’argilite montre sa conformité avec les études précédentes de la zone d’intérêt et que le pH de 7,5 est incontournable pour ne pas dénaturer la roche. L’étude du système Eu-MO montre que les acides organiques n’ont pas d’influence sur la spéciation de l’europium dans l’eau de COx. L’étude expérimentale de l’interaction Eu-Arg confirme que la rétention se fait par sorption sur l’argilite (CEu<6.10-6mol/L) et précipitation dans l’eau de COx (CEu>6.10^(-6)mol/L). Le coefficient de distribution Rd, qui quantifie la sorption, est de 170 ± 30 L/g, valeur élevée conforme aux valeurs documentées sur des argilites naturelles. Enfin, l’étude du système ternaire Eu-MO-Arg montre une légère augmentation de la rétention de Eu en présence de matière organique. Cet effet synergique est très satisfaisant du point de vue de la sûreté du stockage : la présence de ces petits acides organiques naturels ne remet pas en question les propriétés de rétention de l’argilite vis-à-vis de l’europium et des actinides trivalentsBure clay rock (CR) was chosen as host rock for the French high and intermediate level long lived radioactive waste repository. This choice is mostly explained by the retention ability of the Callovo-Oxfordian rock (COx). Bure clay rock contains natural organic matter (OM) that could have an influence on radionuclide retention. The aim of this work is to assess the influence of natural mobile OM on the retention of Eu on clay rock. Eu was chosen as a chemical model for trivalent actinides contained in vitrified waste. Three organic molecules were studied: suberic, sorbic and tiglic acids, small organic acids identified in COx pore water. All the experiments were carried out in an environment recreating COx water (pH=7.5 ; I=0.1 mol/L ; PCO2 =10^(-2) bar).Clay rock sample characterization showed that the sample used in this work was similar to those previously extracted from the area of interest and that it was necessary to maintain pH at 7.5 to avoid altering the clay rock. The Eu-OM system study indicated that organic acids had no influence on Eu speciation in COx water. The Eu-CR system experimental study confirmed that retention implied sorption on CR (CEu<6.10^(-6)mol/L) and precipitation in COx water (CEu>6.10-6mol/L). Distribution coefficient Rd (quantifying sorption) was estimated at 170 ± 30 L/g. This high value is consistent with literature values obtained on clay rocks. The ternary Eu-OM-CR system study showed a slight increase of sorption in the presence of organic matter. This synergistic effect is very satisfactory in terms of storage security: the presence of small organic acids in clay rock does not question retention properties with respect to europium and trivalent actinides
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Griffault, Lise. "Bilan des transferts de matière (majeurs et terres rares) dans les altérations hydrothermales des granites : exemple du granite du ballon d'alsace (vosges méridionales)." Poitiers, 1987. http://www.theses.fr/1987POIT2302.
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Etude de deux systemes d'alteration hydrothermale: - une alteration pervasive, se manifestant par la chloritisation des ferromagnesiens, le formation d'illite dans les plagioclases et la cristallisation de calcite; - une alteration a illite dans les epontes de veines liees a la mise en place de filins de fluorine. Cette etude montre que le comportement geochimique des terres rares ne peut etre assimile au comportement des elements majeurs au cours des processus hydrothermaux ou des mineraux argileux sont formes. Les mecanismes de fixation des terres rares correspondent a des phenomenes de sorption des elements sur les surfaces des particules argileuses et non a des substitutions
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Lahmar, Rabah. "Les sols rouges lessives sur micaschites a chlorites ferriferes (grande kabylie, algerie). Organisation de la couverture pedologique d'un bassin versant. Alteration, pedogenese, morphogenese." Paris 6, 1988. http://www.theses.fr/1988PA066339.
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La premiere partie traite de l'analyse structurale de cete couverture. La carte en courbe de differenciation est discutee : le contenant et le contenu sont analyses; la stabilite de l'information sturcturale et de l'image cartographique lors d'une reduction de la maille ou de l'echelle est abordee. Ainsi la differenciation pedologique est marquee par le transfert de l'argile. Le profil d'eluviation-illuviation est d'autant plus lateral et net que la pente est forte; l'hydrochimie se declenche a l'aval quand la porosite est colmatee par l'argile illuviale. En revanche, la distribution des horizons organiques superficiels est regie par l'erosion. La stabilite de cette couverture epaisse sous des conditions climatiques mediterraneennes agressives est reliee au developpement d'une importante microagregation. L'etude de la stabilite et de la constitution des differentes classes d'agregats montre le role du fer amorphe et de sa liaison avec les acides humiques dans le developpement et la perennite de cette microagregation. Le fer provient en grande partie de l'alteration des chlorites qui aboutit en meme temps a la formation de mineraux a comportement intergrade dont les cales interfoliaires sont essentiellement ferriferes. Deux voies d'approche ont ete suivies pour l'etude de ces mineraux : -l'extraction chimique des amorphes externes et internes et le suivi du comportement a la diffraction rx des argiles traitees : - l'etude de l'alteration des chlorites ferriferes par voie microanalytique
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Kerdjidj, Kamel. "Application de la petrographie et de la geochimie organique a l'histoire thermique de la partie sud-est du bassin triasique du sahara nord-oriental (algerie)." Orléans, 1987. http://www.theses.fr/1987ORLE2051.
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Les regions de gassi touil et de rhourde nauss se situent sur la dorsale amguid-el biod dans la zone des horsts. Etude du point de vue structural. Les phases hercyniennes et autrichiennes sont les plus importantes dans ces regions. Reconstitution de l'histoire thermique basee sur l'interpretation des transformations thermiques subies par les constituants organiques ou mineraux au cours de leur enfouissement. Le gradient geothermique faible au paleozoique pour l'ensemble des regions s'est poursuivi durant le mesozoique dans la region de rhom de nauss par contre il a fortement varie dans celle de gassi touil
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Iwalewa, Tajudeen. "Coupling source term, mineral reactivity and flow in radionuclide transport." Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/265633.
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The focus of this work is to investigate the dissolution of MW25, a non-radioactive simulant of UK high-level nuclear waste borosilicate glass, and to predict its performance in the near field of a geological repository. A single-pass flow-through (SPFT) experimental system was used to measure the forward dissolution rates of MW25. Experiments were conducted in two parts. Experiment Part 1 considers the dissolution of the waste glass in deionised water at 40 and 90 oC and circum-neutral pH. Experiment Part 2 considers the dissolution of the waste glass in simulant groundwaters, with similar compositions to groundwaters of Callovo-Oxfordian clay (lower-strength sedimentary rock (LSSR)) and Borrowdale Volcanic Group rocks (higher-strength rock (HSR)), at 40 oC and pH 7. The forward dissolution rate measured in deionised water was found to be approximately one order of magnitude higher at 90 oC than at 40 oC. A similar release was observed for Si, Mg and Al at 40 oC and 90 oC, whereas the B, Cs, Na, Li and Mo showed an order of magnitude increase when the temperature was increased from 40 to 90 oC for low q/S values. The activation energy (Ea) of the reactions shows that the dissolution process is a surface phenomenon. At 90 oC the net effect of the processes governing MW25 dissolution led to the preferential release of boron and alkali metals relative to the release of Si during the transient dissolution stage, accompanied by an increase in the concentration of silicic acid. This suggests that the solution activity of silicic acid at a higher temperature has a weak influence on the release of the mobile elements. The forward dissolution rate measured in LSSR simulant groundwater was found to be slightly higher than that measured in HSR simulant groundwater. The dissolution behaviour of MW25 in both groundwaters is consistent with its behaviour in deionised water at 40 oC, with the dissolution rates of elements increasing as flow rates were increased. However, forward dissolution rates measured in the simulant groundwaters were lower than the forward dissolution rates measured in deionised water under these experimental conditions. This is attributable to the interaction of the components of the simulant groundwaters with the glass, as revealed by post-reaction surface analyses, and a consequential lower alkalinity of the leachates collected in the experiments with simulant groundwater than in deionised water. Reactive chemical transport simulations of waste glass dissolution and radionuclide release in a hypothetical near field were conducted over a time span of a million years with GoldSim. The results showed that enclosing the waste glass in a steel canister covered by a copper canister and emplacing the waste package in a granite host rock is optimal for the long-term isolation of the radionuclides. The waste glass was found to play a significant role in the overall performance of the near field. This study features a new method for estimating the surface area of reacted glass powder more accurately than the geometric surface area estimate, which is the preferred standard method among researchers.
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Li, Yidan. "Filtrations statiques et dynamiques de différents systèmes argile, électrolytes, polymère." Orléans, 1996. http://www.theses.fr/1996ORLE2014.
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Les propriétés de filtration de fluides de forage modèles composés d'eau, d'argile, d'électrolytes (nacl, cacl2 et kcl) et de polymères (carboxymethylcellulose et ter polymère sulfone) ont été étudiées en condition statique et dynamique sur papier filtre et tranches de roches. Les expériences de filtration, combinées à l'observation des cakes par cryomicroscopie à balayage et microscopie électronique à transmission, mettent en évidence l'importance de la taille et la forme des particules d'argiles, ainsi que leur mode d'association en suspension, sur la texture du cake, sa perméabilité et ses propriétés de relaxation. Ces paramètres dépendent de la nature de l'électrolyte. Le polymère réduit la perméabilité du cake en améliorant la dispersion de l'argile en suspension, mais surtout en colmatant le réseau poreux par ses propriétés d'auto-agrégation. Le mode de dépôt en dynamique est lie à l'état d'agrégation de la suspension au départ, sa polydispersite et sa sensibilité au cisaillement ainsi qu'à la perméabilité du cake construit dans les premiers instants de la filtration. Dans tous les cas, le processus de croissance du cake est ralenti et on obtient des volumes de filtrat plus élevés qu'en statique. Le cisaillement a deux effets: d'une part dissocier les agrégats lâches présents en suspension et d'autre part exercer un tri granulométrique des particules dans le cas d'une suspension polydispersée. À fort gradient de cisaillement on obtient rapidement un cake fin d'épaisseur constante. L’épaisseur de ce cake limite dépend de la fraction de petites particules présentes en suspension, ou susceptibles d'être formées par dissociation d'agrégats lâches sous l'action du cisaillement. La perméabilité du cake limite forme en dynamique est, comme en statique, conditionnée par la taille et la forme des particules qui le constituent ou par la présence d'un polymère réducteur de filtrat. Les filtrations réalisées sur un grès de fontainebleau permettent de visualiser le cake interne et de préciser les risques d'endommagement d'une roche réservoir par le fluide de forage
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Blanchet, François. "Etude géomécanique de glissements de terrain dans les argiles glacio-lacustres de la vallée du Drac." Phd thesis, Grenoble 1, 1988. http://www.theses.fr/1988GRE10117.
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Nous avons etudie un glissement de terrain affectant le lotissement du mas d'avignonet, situe sur la rive gauche de la retenue du monteynard. Une campagne de reconnaissance in situ comportant sondages, releves geologiques, indices de mouvement, mesures inclinimetriques, topographiques et piezometriques nous a permis de mettre en evidence plusieurs surfaces de deformations. On propose des mecanismes probables de rupture de ces glissements; on definit leur geometrie et on evalue les valeurs residuelles des caracteristiques mecaniques a la rupture des argiles litees, formation a l'origine de nombreuses instabilites dans la region. On analyse la stabilite du lotissement ainsi que le role des seismes sur la stabilite a long terme du versant
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Cerisuelo, Marc. "L'Instauration du cinéma : Poétique des films et interprétation : L'exemple des métafilms hollywoodiens." Paris 3, 1998. http://www.theses.fr/1998PA030188.
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La presente etude se propose d'illustrer les liens entre la poetique des films, l'histoire du cinema et la necessite d'une approche interpretative d'inspiration litteraire et philosophique. Une longue introduction presente la "discipline" en justifiant le recours au terme de poetique, et s'attache a demontrer - ou a rappeler - que le cinema n'est pas l'art de l'image. Une premiere partie definit la notion de metafilm, en la distinguant des autres productions consacrees au cinema et en proposant l'idee d'un genre ouvert. La seconde partie etudie le deploiement historique du genre a hollywood. La conclusion rappelle l'importance du mepris comme fil conducteur des etudes metafilmiquesThe object of this study is to establish the relationships between poetics of film, film history and the claim of an interpretation based upon a literary background and a philosophical point of view. A "metafilm" is not just one more "movie-about-themovies". This study will attempt to show how, from show people to fedora, the hollywood tradition provides a real discourse of the film