Ce travail de thèse a pour objet l’étude du comportement hydromécanique endommageable des géomateriaux non saturés. Plus précisément, cette recherche est appliquée à l’étude du comportement de galeries de stockage de déchets radioactifs en formation géologique profonde. Dans un premier temps, après avoir résumé les principaux traits du comportement hydromécanique des géomateriaux, en insistant sur l’effet de la succion et de l’endommagement mécanique, un nouveau modèle PPE-NS couplant les aspects hydromécaniques, de plasticité et d’endommagement isotrope est présenté. Etabli dans le cadre de la thermodynamique des milieux poreux, il est basé sur le concept de contrainte effective plastique et de la pression interstitielle équivalente. Supposant une distribution bimodale de tailles des pores pour les milieux poreux endommagés, l'effet d'endommagement sur le comportement hydraulique est modélisé au moyen des fonctions phénoménologiques. L’endommagement intervient donc aussi bien sur le comportement mécanique qu'hydraulique dans ce modèle. La prise en compte des contributions à l’énergie des interfaces venant à la fois de l'interaction mécanique entre les phases solide et fluide (via la pression équivalente) et du mécanisme physico-chimique de rétention d'eau (via la fonction de rétention d’eau) permet à ce modèle de décrire de façon pertinente le couplage bilatéral entre elles. Dans un deuxième temps, ce modèle rhéologique est appliqué au comportement de l’argillité du Callovo-Oxfordian, qui est potentiellement la roche hôte du stockage de déchets nucléaires en France, afin d’étudier les évolutions hydromécaniques d’une galerie type selon son cycle de vie simplifié. Tout d’abord, ce modèle est validé par des essais mécaniques et hydrauliques au laboratoire, en considérant des échantillons « homogènes ». Ensuite, l’approche analytique est utilisée pour constituer une solution exacte de référence de ce problème dans un cas limite d’une roche hôte poro-viscoplastique saturée. Cette solution permet de mieux comprendre l’effet du fluage sur le comportement de la galerie et aussi de tester la fiabilité d’autres solutions numériques complexes développées par la suite. Enfin, l’approche numérique des éléments finis est mise en œuvre afin d'implémenter le nouveau modèle PPE-NS dans un code de calcul initialement développé au LGCB (Laboratoire Génie Civil et Bâtiment). Sa validité est partiellement vérifiée en considérant le comportement « limite » en photoélasticité d'une galerie non revêtue ou des solutions quasi-analytiques ont été développées. Des études paramétriques dans le cas général d'un tunnel revêtu montrent la cohérence du modèle et mettent en lumière l’influence de la désaturation sur le comportement de la galerie. / This thesis aims to study the damageable hydromechanical behavior of unsaturated geomaterials. More precisely, the research is applied to study the behavior of underground galleries of radioactive waste disposals in deep geological formations. Firstly, after summarizing the main features of the hydro-mechanical behavior of geomaterials, emphasizing the effect of suction and damage, a new model PPE-N coupling hydromechanical interactions with plasticity and isotropic damage is presented. Established in the framework of thermodynamics of porous media, it is based on the concept of the so called plastic effective stress and equivalent pore pressure. Assuming a bimodal pore size distribution for cracked porous media and using the concept of bundle cylindrical capillaries, damage effects on hydraulic behaviour (water retention curve and hydraulic conductivity) is modelled using phenomenological functions. The accountance of the contributions to the interfacial energy from the mechanical internations between solid and fluid phases (via theequivalent pore pressure) as well as the physico-chemical mechanism of water retention (via the water retention function) enables this model to describe in apertinent manner bilateral couplings between them.Secondly, this constitutive model is applied to Callovo- Oxfordian argillite, which is the potential host rock for the French nuclear waste disposal, and then to study the evolution of the hydromechanical responses of an underground gallery according to its simplified life cycle. The model is first validated against a range of mechanical and hydraulic laboratory tests, considering "homogeneous" samples. The analytical approach is then used to provide an exact reference solution of this problem in the limiting case of a saturated poro-viscoplastic host rock. This solution allows to better understand the effect of creep on the behavior of the gallery and also to test the precision of other complex numerical solutions . Finally, the numerical approach using finite elemnts is used to implement the new model EPP-NS in a computer code originally developed in LGCB (Laboratoire Genie Civil et Batiment). Its validity is partly checked by examining the poroelastic behavior of an unlined tunnel where quasi-analytical solutions have been developed. Parametric studies in the generalcase of a lined tunnel demonstrate the consistency of the model and highlight the influence of desaturation on the behavior of the gallery.

<p>Moisture can significantly affect flexible pavement performance. As such, it is crucial to remove moisture as quickly as possible from the pavements, mainly to avoid allowing moisture into the pavement subgrade. In the 1990s the Indiana Department of Transportation (INDOT) adopted an asphalt pavement drainage system consisting of an open-graded asphalt drainage layer connected to edge drains and collector pipes to remove moisture from the pavement system.</p> <p>Over the intervening two decades, asphalt pavement materials and designs have dramatically changed in Indiana, and the effectiveness of the pavements drainage system may have changed. Additionally, there are challenges involved in producing and placing open-graded asphalt drainage layers. They can potentially increase costs, and they tend to have lower strength than traditional dense-graded asphalt pavement layers. </p> <p>Given the potential difficulties, the overall objective of this research was to evaluate the effectiveness of the INDOT’s current flexible pavement drainage systems given the changes to pavement cross-sections and materials that have occurred since the open-graded drainage layer was adopted. Additionally, the effectiveness of the filter layer and edge drains were examined.</p><p><br>Laboratory experiments were performed to obtain the hydraulic properties of field-produced asphalt mixture specimens meeting INDOT’s current specifications. The results were used in finite element modeling of moisture flow through pavement sections. Modeling was also performed to investigate the rutting performance of the drainage layers under various traffic loads and subgrade moisture conditions in combination with typical Indiana subgrade soils. The modeling results were used to develop a design tool that can assist the pavement designer in more accurately assessing the need for pavement drainage systems in flexible pavements.<br></p>

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Made available in DSpace on 2016-12-08T15:50:03Z (GMT). No. of bitstreams: 1 PGMS12DA009.pdf: 7314998 bytes, checksum: 8e93659478a7813ba0b934959e229681 (MD5) Previous issue date: 2012-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Studies on the retention and availability of water are scarce for humid subtropical and temperate regions in the Southern Hemisphere. The objectives of this study were to evaluate, generate and validate some pedotransfer functions (PTFs) to estimate the retention and the availability of water in soils of Santa Catarina. Were sampled 44 profiles, in areas under different vegetal coverings, to determine the water retention at suctions from zero to 1.500 kPa, the particles size distribution (7 classes), the organic matter content, the bulck density and particle density of soil, the conductivity hydraulic, and the aggregate stability. Regarding the attributes, soils with finer texture and / or more organic matter retain higher water content, where the organic matter is the main attribute that governs the availability of water, mainly in the surface horizons. Some classes of sand, mainly very fine sand, fine and coarse fractions, have greater effects on water availability than the silt fraction. The soils with contrasting textural classes, with high contents of clay or sand, have the same content of water available, although the sand soils have very low field capacity. Increased water availability occurs in soils with textural class loam, with higher content of organic matter and the lower availability occurs in sand class soils. In relation to lithology, there is a higher retention in soils derived from igneous extrusive rocks of the Serra Geral Formation, metamorphic, intrusive igneous, and sedimentary with fine texture, and a lower retention in those derived from rocks or sedimentary deposits rich in quartz. Increased availability of water occurs in soils derived from siltstone and less in soils derived from granite and recent alluvial deposits. Regarding soil classes (suborders), the water retention is higher in Cambisols, Ferralsols and Nitosols, and lower in Quartzarenic Neosols. In relation the regions, the soils of the Midwest and West, Serrano Highlands and Valley of Itajaí have high water retention, the intermediary are the Eastern Sierra, and lower in the coast. Humic Cambisols and Entisols, located in the Serrano Highlands has increased availability of water, mainly because of high contents of organic matter. In relation to soil types in the normative instruction n. 2/2008 of the MAPA (BRAZIL, 2008), which classifies the soils as a function of clay and sand, it is observed that is not adequate to classify the soils of Santa Catarina in terms of availability of water, although, the hydraulic conductivity of the unsaturated soil is lower in Type 1 soils. In relation the pedotransfer functions of literature, they better estimate the retention than water availability and with greater precision by the functions originated from climate regions subtropical and for the subsurface horizons of the soil. Most functions evaluated underestimates the water retention, with greater deviations in soils with 20-60 % clay. About the functions generated for the soils of Santa Catarina, the estimation of retention and availability of water was better in those adjusted separately for surface and subsurface horizons. To estimate the water retention, the point PTFs must be used including data of the texture, organic matter and their interactions. To estimate the availability, the point PTFs should include the five classes of sand, silt, clay, organic matter, soil bulk density, soil particles density, total porosity and their interactions. The parametrics PTFs estimate properly the water retention curve for most of the textural classes of the soil, when data of texture, organic matter, soil bulk density, soil particles density, total porosity and their interactions are included as predictors. The class PTFs estimate properly the water retention curve for most of the soil textural classes of Santa Catarina / Estudos sobre a retenção e disponibilidade de água são escassos para as regiões de clima subtropical ou temperado úmido do hemisfério sul. Os objetivos deste estudo foram avaliar, gerar e validar funções de pedotransferência (FPTs) para estimar a retenção e a disponibilidade de água em solos de Santa Catarina. Foram amostrados 44 perfis, em áreas sob diferentes coberturas vegetais, para determinar a retenção de água nas sucções de zero até 1.500 kPa, a distribuição do tamanho de partículas (7 classes), o teor de matéria orgânica, a densidade do solo e de partículas, a condutividade hidráulica e a estabilidade de agregados. Em relação aos atributos, solos com textura mais fina e/ou com maior teor de MO retêm maior conteúdo de água, sendo a MO é o principal atributo que governa a disponibilidade de água, principalmente nos horizontes superficiais. Algumas classes de areia, principalmente as areias muito fina, fina e grossa, possuem maiores efeitos sobre disponibilidade de água do que a fração silte. Os solos com classes texturais contrastantes, com elevados teores de argila ou de areia, disponibilizam o mesmo conteúdo de água disponível, embora os arenosos tenham baixa capacidade de campo. Maior conteúdo de água disponível ocorre em solos das classes com textura franca e com maior teor de MO, enquanto que a menor disponibilidade ocorre em solos da classe areia. Em relação à litologia, ocorre uma maior retenção em solos derivados de rochas ígneas extrusivas da Formação Serra Geral, e de rochas metamórficas, ígneas intrusivas e sedimentares de textura fina, e menor nos derivados de rochas ou depósitos sedimentares ricos em quartzo. Maior disponibilidade de água ocorre em solos derivados de siltitos e o menor em solos derivados de granito e de depósitos aluvionares recentes. Em relação às classes de solos (subordens), a retenção de água é maior nos Cambissolos, Nitossolos e Latossolos e menor nos Neossolos Quartzarênicos. Em relação às regiões, os solos do Meio Oeste e Oeste, Planalto Serrano e Vale do Itajaí possuem elevada retenção de água, euquanto que, nos da Serra Leste é intermediária e os do Litoral é baixa. Os Cambissolos Húmicos e os Neossolos Litólicos, localizados no Planalto Serrano, têm maior disponibilidade de água, principalmente devido aos elevados teores de matéria orgânica. Em relação aos tipos de solos da instrução normativa n. 2/2008 do MAPA (BRASIL, 2008), que classifica os solos em função do teor de argila e areia, observa-se que a mesma não é adequada para classificar os solos catarinenses quanto a disponibilidade de água. Entretanto, a condutividade hidráulica não saturada é menor nos solos do Tipo 1. Em relação às funções de pedotransferência (FPTs) publicadas na literatura, elas estimam melhor a retenção do que a disponibilidade de água, com maior precisão pelas funções originadas de regiões de clima subtropical e para os horizontes subsuperficiais do solo. A maioria das funções avaliadas subestima a retenção de água, com erros maiores nos solos com 20 a 60% de argila. Quanto às funções geradas para os solos de Santa Catarina, as que melhor estimam a retenção e disponibilidade de água são aquelas ajustadas separadamente para os horizontes superficiais e subsuperficiais. Para estimar a retenção de água devem ser utilizadas as FPTs pontuais que incluem dados de textura, matéria orgânica do solo e suas interações. Para estimar a disponibilidade de água devem ser utilizadas as FPTs pontuais que utilizam as cinco classes de areia, silte, argila, matéria orgânica, densidade do solo e de partículas, porosidade total e suas interações. As FPTs paramétricas estimam adequadamente a curva de retenção de umidade do solo para a maioria das classes texturais, quando são incluídos dados de textura, matéria orgânica, densidade do solo e de partículas, porosidade total e suas interações como variáveis preditoras. As FPTs de classe estimam adequadamente a curva de retenção de água do solo para a maioria das classes texturais dos solos de Santa Catarina

Under hösten 2019 har Vattenfall Research &amp; Development byggt en experimentell jordfyllningsdamm i Älvkarleby med dimensionerna 20x15x4 meter. Delar av experimentdammen är konventionellt konstruerade och har installerats med geoteknisk utrustning som utgörs av bland annat inklinometrar och portrycksgivare. Andra delar av experimentdammen har byggts in med defekter som ska representera åldersrelaterade skador eller utförandefel vid konstruktion. Experimentdammen ger möjlighet att under realistiska och kontrollerade förhållanden studera det mekaniska beteendet i samband med fyllning av vatten och vidare drift med hjälp av den geotekniska instrumenteringen samt med stöd av numerisk modellering. I detta examensarbete, som utgör en del av Luleå tekniska universitets forskningsprojekt mot experimentdammen, har experimentdammens beteende i form av deformationer och portryck studerats under uppfyllnad och drift fram till sommaren 2021. Detta har utförts genom simuleringar i det finita elementprogrammet PLAXIS 2D 2019 för en tvärsektion av experimentdammen i plant-deformationstillstånd. Mätpunkterna i modellen har baserats på faktisk placering av den geotekniska instrumenteringen. Den finita elementmodellen av experimentdammen har konstruerats och fyllts med vatten enligt dokumentation från fält. En flödes-deformationsanalys, med den konstitutiva modellen Hardening Soil och den hydrauliska modellen van Genuchten, har tillämpats för att modellera den simultana utvecklingen av portryck och deformationer under uppfyllnad. Materialparametervärden för den finita elementmodelleringen har erhållits från Vattenfall R&amp;D, relevant litteratur och från fält- och laboratorieförsök. I fält har vattenvolymeterförsök utförts på tätkärnan och i laboratoriemiljö har modifierad proctorpackning, dränerade konventionella triaxialförsök, permeabilitetsförsök och övertryckskapillarimeterförsök utförts på tätkärnans material. Resultatet från övertryckskapillarimeterförsök har anpassats mot den hydrauliska modellen van Genuchten för att uppskatta en vattenbindningskurva som beskriver det icke-linjära förhållandet mellan jordens vatteninnehåll och porundertryck, det vill säga det omättade förhållandet. Vattenbindningskurvor för övriga materialzoner har uppskattats baserat på litteratur. Verktyget PLAXIS SoilTest har använts för att optimera materialparametervärden för tätkärnan mot resultat från utförda triaxialförsök. Materialparametrarna E50ref, Eoedref, Eurref, m, c, och ϕ har optimerats fram till brott i triaxial belastning. En känslighetsanalys har utförts för reduktion av filterzonernas och stödfyllningens styvhetsmoduler och deras inverkan på horisontella deformationer i dammkroppen under uppfyllnad. Känslighetsanalysen indikerar att finfiltrets styvhetsmoduler har störst inverkan och grovfiltrets styvhetsmoduler har minst inverkan på de horisontella deformationerna. Studiens resultat visar att magnituden av horisontella och vertikala deformationer kommer vara som störst i den övre delen av dammkroppen och uppgår där till 3,5 respektive 4,0 mm. Dammkroppens huvudsakliga rörelse kommer vara i nedströms riktning och det observerades hur en kontaktzon mellan uppströms filterzon och tätkärnan utgör en gräns för riktning av deformationer. Faktiskt uppmätta rörelser i installerade inklinometrar kunde inte jämföras mot deformationer i den finita elementmodellen eftersom författarens tolkning indikerar på att botten av inklinometrarna har rört på sig, och mätpunkterna i botten av modellen är fixerade. Modellen visar hur en fördröjd utveckling av vattenmättnad sker genom tätkärnan, där uppströms sida av tätkärnan reagerar snabbare på förändringar i vattennivå jämfört med nedströms sida av tätkärnan som uppvisar en fördröjd respons. Vid en sänkning av vattennivån observerades hur tätkärnan håller kvar vatten ovan portryckslinjen medan de grövre materialen dränerar i takt med vattennivåns sänkning. Utvecklingen av de simulerade portrycken i modellen under uppfyllnad och drift överensstämmer bra med de uppmätta portrycken i experimentdammen, när portrycken är positiva. Det observeras hur den finita elementmodellen överskattar negativa portryck (porundertryck). Portrycken i modellen når ett stadigt tillstånd ungefär 115 dagar efter att fyllningen av vatten påbörjats. Den finita elementmodellen lyckas att återge det teoretiska beteendet av jordfyllningsdammar under fyllning i form av huvudsakliga riktningar av deformationer och utveckling av vattenmättnad i tätkärnan. Denna studie bidrar till en djupare förståelse för experimentdammens, och i allmänhet jordfyllningsdammars, mekaniska beteende under uppfyllnad. Resultaten från den finita elementmodellen kan ur ett dammsäkerhetsperspektiv användas för erhålla indikationer på utvecklingen av deformationer, portryck och vattenmättnadsgrad i jordfyllningsdammar under uppfyllnad, och även under en tillfällig sänkning av vattennivån under den första fyllningen. Studien ger också indikationer på vilka materialparametrar som är viktiga vid numerisk modellering av mekaniskt beteende i jordfyllningsdammar. / During the autumn of 2019, Vattenfall Research &amp; Development constructed an experimental embankment dam in Älvkarleby with the dimensions 20x15x4 metres. Parts of the experimental dam are conventionally constructed and have been equipped with geotechnical instrumentation which consist of, among other things, inclinometers and pore pressure transducers. Other parts of the experimental dam have built in defects to represent age-related damages or execution errors during construction. The experimental embankment dam provides the opportunity to, under realistic and controlled conditions, study the mechanical behaviour during filling of water and operation by means of the geotechnical instrumentation and the use of numerical modelling. In this master’s thesis, which forms part of Luleå University of Technology’s research project towards the experimental dam, the behaviour of the experimental dam in terms of deformations and pore pressures have been studied during filling and operation until the summer of 2021. This has been performed by simulations in the finite element program PLAXIS 2D 2019 for a cross section of the experimental dam under plane-strain conditions. Measuring points in the model have been based on the actual location of the geotechnical instrumentation. The finite element model of the experimental dam has been constructed and filled according to documentation from field. A fully-coupled flow deformation analysis, with the constitutive model Hardening Soil and hydraulic model van Genuchten, has been utilised to model the simultaneous development of pore pressure and deformations during filling. Values of material parameters for the finite element modelling have been received from Vattenfall R&amp;D, relevant literature and from field- and laboratory tests. In the field, balloon tests have been performed on the core material. In laboratory environment, modified proctor compaction tests, drained conventional triaxial tests, permeability tests and pressure plate tests have been performed on the core material. Results from the pressure plate tests have been adapted to the hydraulic model van Genuchten to estimate a soil-water characteristic curve in order to describe the non-linear relation between the water content and suction in the soil, i.e. unsaturated conditions. Soil-water characteristic curves for the other material zones have been estimated based on literature. The tool PLAXIS SoilTest has been used to optimise material parameter values of the core against the results from conducted triaxial tests. The material parameters E50ref, Eoedref, Eurref, m, c, and ϕ have been optimised until failure in triaxial loading. A sensitivity analysis has been carried out, by reducing stiffness moduli of the filter zones and the shoulder material, to investigate the influence on horizontal deformations in the dam body during filling. The sensitivity analysis indicates that the stiffness moduli of the fine filter have the largest impact and the stiffness moduli of the coarse filter have the least impact on the horizontal deformations. The results of the study show that the magnitude of horizontal and vertical deformations will be largest in the upper part of the dam body and amounts to 3.5 and 4.0 mm, respectively. The main movement of the dam body will be in the downstream direction and it was observed how a contact zone between the upstream filter zone and the core forms a boundary for direction of deformations. Actual measured movements in the installed inclinometers could not be compared to deformations in the finite element model because the author’s interpretation indicates that the bottom of the inclinometers have moved, and the measuring points at the bottom of the model are fixed. The model shows how a delayed development of saturation occur through the core, where the upstream side of the core responds more quickly to changes in water level compared with the downstream side of the core which show a delayed response. At a lowering of the water level, it was observed how the core retains water above the phreatic line while the coarser materials drain as the water level decreases. Development of the simulated pore pressures in the model during filling and operation corresponds well with the measured pore pressures in the experimental dam, when the pore pressures are positive. It is observed how the finite element model overestimates negative pore pressures (suction). The pore pressures in the model reaches a steady state approximately 115 days after filling of water started. The finite element model succeeds in reproducing the theoretical behaviour of embankment dams during filling in terms of main directions of deformations and development of saturation in the core. This study contributes to a deeper understanding of the experimental dam, and in general mechanical behaviour of embankment dams during filling. The results from the finite element model can be used from a dam safety perspective to obtain indications on the development of deformations, pore pressures and degree of saturation in embankment dams during filling, and also for a temporary lowering of the water level during the first filling. The study also provides indications of which material parameters that are of importance in numerical modelling of mechanical behaviour in embankment dams.

The most important characteristics of each soil is its hydro-physical properties, which include retention curve. Retention curve expresses the relationship between humidity and pressure head. It is course affected by many factors such as grain size and mineralogical composition, humus content, structure and bulk density of dry soil. This thesis deals with direct and indirect determination of one of the basic hydraulic characteristics of the soil, soil moisture retention curve. For laboratory determination of moisture retention curves were used for sand tank and pressure instruments. Measured body retention curves were optimized RETC program.For indirect determination of retention curves were used Pedotransfer function by Wösten et . al .(1998 ) , derived from the European soils and under HYPRES Šútora and Štekauerová (2000). As in the project Wösten et al . (1998), PTF were processed for arable land in the area. The accuracy of both models PTF was assessed by the correlation coefficient R and standard error RMSE. Simple models PTF provide estimates of retention curves with sufficient accuracy for practical use in the locality.

This thesis deals with direct and indirect determination of soil hydraulic characteristics (retention curve and hydraulic conductivity) in the locality of Bohaté Málkovice. For laboratory determination of soil moisture retention curve is used sand tank and pressure relief device. For the indirect determination of soil hydraulic characteristics is used computer software Rosetta, which includes 5 models of pedotransfer functions. For estimatiton of retention curves are applied previously derived pedotransfer function (continuous parametric PTF and point PTF).