Tesi sul tema "Barrages en terre – Fiabilité"
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GAOUAR, EL MEHDI. "Approche fiabiliste de la stabilite des barrages en terre par simulation de champs aleatoires". Clermont-Ferrand 2, 1997. http://www.theses.fr/1997CLF21975.
Testo completoGuo, Xiangfeng. "Probabilistic stability analysis of an earth dam using field data". Thesis, Université Grenoble Alpes, 2020. http://www.theses.fr/2020GRALI017.
Testo completoUncertainties of soil properties are widely encountered in the field of geotechnical engineering especially for earth dams which are constructed with earthen materials. In recent years, there is an increasing need, motivated by the deficiencies of the traditional deterministic approach or guided by the national regulations such as in France, of accounting for these uncertainties for a safe assessment of large dams particularly in the framework of risk analysis studies. However, probabilistic analyses are still complex and not so easy to implement in practice due to the limited number of in-situ measurements, expensive computation efforts and lack of implementation of reliability methods in commercial simulation tools. Moreover, most of the previous studies are based on academic cases and hypothetic data.This work attempts to deal with the aforementioned issues by providing a probabilistic analysis study for the stability of a real earth dam using available field data. This study includes the following main elements: (1) definition of the soil variability by using the available measurements; (2) development of the deterministic models; (3-4) dam probabilistic analyses using the random-variables and random-fields approaches; (5) three-dimensional reliability analysis of the considered dam. Advanced reliability methods, such as the adaptive surrogate modelling, are introduced for the studied earth dam problem. This allows accurately estimating the dam failure probability and the safety factor statistics with a significantly reduced calculation time. In addition, some issues, that remain unknown or unclear in the field of the dam probabilistic analysis, are discussed (e.g. global sensitivity analysis of the soil hydraulic and shear strength parameters; performance survey of five reliability methods; simulation/comparison of three different kinds of random fields: generic (unconditional-stationary), conditional and nonstationary). The presented work, based on real measurements, could be a good supplement to the existing probabilistic studies of geo-structures. Readers will find useful information from the obtained results in order to better solve the practical geotechnical problems in a probabilistic framework
Le, Thu Nga. "Modélisations du comportement des barrages en terre sous séismes". Grenoble INPG, 2006. http://www.theses.fr/2006INPG0039.
Testo completoLn most cases of past ruptures of earth-fill dams throughout the world, the main cause of failure is the liquefaction of poorly compacted pulverulent materials. An easy to use constitutive model capable of describing soil behavior under cyclic and seismic loadings is required by civil engineering consultancies in the design, the dimensionning and the assessment of the liquefaction risk of these works. TheBRO model was developed to meet these needs. This model was integrated in a widely-used, commercial code, FLAC (a finite differences code). The calibration of its parameters is clearly defined and easy to understand. The model is validated by the reproduction of the behavior of hydraulic engineering works in real in-situ conditions: the two San Fernando dams (California) du ring two earthquakes. A further application of this model is the study of the seismic stability of alluvial dikes. A sensiblity study generalizes the results by analysing of main indicators of the harmful impact of earthquake signais in order to extract the most representative ones
Dendani, Hédi. "Comportement de matériaux de barrages en terre : étude expérimentale et modélisation". Grenoble INPG, 1988. http://www.theses.fr/1988INPG0030.
Testo completoDendani, Hédi. "Comportement de matériaux de barrages en terre étude expérimentale et modélisation /". Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb37613160f.
Testo completoPimentel, Torres Gaspar Ana Patricia. "Contribution to control uncertainties in numerical modelling of dam performances : an application to an RCC dam". Thesis, Châtenay-Malabry, Ecole centrale de Paris, 2014. http://www.theses.fr/2014ECAP0053/document.
Testo completoThe use of fully probabilistic approaches to account for uncertainties within dam engineering is a recently emerging field on which studies have been mostly done concerning the safety evaluation of dams under service. This thesis arises within this framework as a contribution on moving the process of risk analysis of dams beyond empirical knowledge, applying probabilistic tools on the numerical modelling of a roller compacted concrete (RCC) dam during its construction phase.The work developed here aims to propose a methodology so as to account for risks related to cracking during construction which may compromise the dam’s functional and structural behaviour.In order to do so, emphasis is given to uncertainties related to the material itself (i.e.strength, water-to-cement ratio, among others) as well as to ambient conditions during the construction phase of RCC dams. A thermo-chemo-mechanical model is used to describe theRCC behaviour. Concerning the probabilistic model, two aspects are studied : how the uncertainties related to the input variables are propagated through the model, and what is the influence of their dispersion on the dispersion of the output, assessed by performing a global sensitivity analysis by means of the RBD-FAST method. Also, spatial variability of some input parameters is accounted for through bi-dimensional random fields. Furthermore, a coupling between reliability methods and finite element methods is performed in order to evaluate the cracking potential of each casted RCC layer during construction by means of a cracking density concept. As an important outcome of this applied research,probability curves for cracking density within each casted layer as functions of both age and boundary conditions are predicted, which is believed to be an original contribution of this thesis. The proposed methodology may therefore be seen as a contribution to help engineers understand how uncertainties will affect the dam behaviour during construction and rely on it inthe future to improve and support the design phase of the dam project
Saint-Hilaire, Patrick. "Étude de la saturation progressive des noyaux de barrages en till compactes". Sherbrooke : Université de Sherbrooke, 2001.
Cerca il testo completoGuellouz, Lamia. "Modélisation du couplage hydraulique mécanique dans les sols non saturés : application aux barrages en terre". Aix-Marseille 2, 1995. http://www.theses.fr/1995AIX22019.
Testo completoDJILALI, BERKANE LAIEB ZOHRA. "Evaluation numérique d'un coefficient de sécurité cinématique pour les barrages et les ouvrages en terre". Université Joseph Fourier (Grenoble), 1997. http://www.theses.fr/1997GRE10193.
Testo completoDezert, Théo. "Combinaison d'informations ponctuelles et volumiques pour le diagnostic d'ouvrages en terre soumis à des risques hydrauliques". Thesis, Nantes, 2019. http://www.theses.fr/2019NANT4061.
Testo completoIn France, the river protection levees extend over more than 8,600 km. These structures are very heterogeneous, due to their construction and their history (breaks and repairs, extensions ...). Breaks of work are likely to lead to disastrous consequences such as loss of lives, economic and environmental disasters. In order to prevent the risk of breakage, special supervision of the protection levees is required. This surveillance begins with a visual recognition of the object of study as well as historical and bibliographic research. Recognized methodologies for the assessment of hydraulic structures including complementary geotechnical and geophysical reconnaissance methods are also being used. This work presents a new way of combining data from these two types of information sources, taking into account the specificities of each kind of method (level of imperfection associated with the data, spatial distribution of the information). This new methodology considers the framework fixed by the theory of belief masses and improves the characterization of lithological sets within levees by providing information on the level of conflict between information sources while proposing a confidence index associated with the results. The methodology is implemented through examples of subsoil sections characterized by synthetic and experimental data as well as by data from a real earthen levee
Bordeleau, Charles-Antoine. "Effet des charges lourdes sur les barrages en remblai : déformation permanente d'un noyau d'argile". Master's thesis, Université Laval, 2021. http://hdl.handle.net/20.500.11794/69366.
Testo completoTran, Duc Kien. "Modélisation numérique discrète de l'érosion interne par renard hydraulique dans les barrages ou digues en terre". Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEC055/document.
Testo completoThe work reported in this thesis consists in a discrete modelling of the backward front propagation of an erosion pipe, as can take place in embankment dams or dikes. Some numerical tools have been developed to this end, based on the coupling between the Discrete Element Method (DEM) and the Lattice Boltzmann Method (LBM) for the representation of the solid and uid phases, respectively. The implementation of DEM follows a standard molecular dynamics approach and the interaction among grains are regulated by unilteral frictional visco-elastic and breakable visco-elastic bonds, in order to take into account a slightly cohesive soil behaviour. The LBM was implemented according to the Multiple Relaxation Time (MRT) scheme along with an interpolated non-slip conditions for moving boundaries, in order to improve the numerical stability of the calculations. The coupling scheme is described along with the criteria for the numerical parameters of the two methods. A representative specimen of a granular soil located at the front of an erosion pipe is first assembled by a \dry" preparation precedure and then tested under fully-saturated conditions and increasing hydraulic load over time. Backward erosion is takes place in the form of clusters of grain being eroded at the erosion front after a degradation of the material due to the breakage of tensile bonds. The other interesting feature that was observed is the creation of arches of compressive force chains. These arches enabled the specimen to maintain a stable or metastable configuration under the increasing hydraulic load
Bekkouche, Abdelmalek. "Sécurité des grands barrages en terre : approche probabiliste des problèmes d'écoulement liés aux reconnaissances et contrôles". Châtenay-Malabry, Ecole centrale de Paris, 1987. http://www.theses.fr/1987ECAP0038.
Testo completoMAHFOUD, OULD AMY. "Modelisation numerique des ecoulements et des deformations dans les barrages en terre construits sur sols mous". Marne-la-vallée, ENPC, 1990. http://www.theses.fr/1990ENPC9024.
Testo completoBekkouche, Abdelmalek. "Sécurité des grands barrages en terre approche probabiliste des problèmes d'écoulement liés aux reconnaissances et contrôles /". Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37602709w.
Testo completoParish, Yousef. "Analyse numérique du comportement sismique des barrages en terre : influence de la plasticité et de la pression d'eau". Lille 1, 2007. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2007/50376-2007-Parish.pdf.
Testo completoBenzenati, Ikhlef. "Modélisation du comportement dynamique des sols saturés appliquée aux barrages et effets de site". Châtenay-Malabry, Ecole centrale de Paris, 1993. http://www.theses.fr/1993ECAP0275.
Testo completoDavoudi, Mohammad Hadi. "Evolution of permeability in earth dam cores made of compacted till". Thèse, Université de Sherbrooke, 1999. http://savoirs.usherbrooke.ca/handle/11143/1702.
Testo completoMahfoud, Ould Amy. "Modélisation numérique des écoulements et des déformations dans les barrages en terre construits sur des sols mous". Phd thesis, Ecole Nationale des Ponts et Chaussées, 1990. http://tel.archives-ouvertes.fr/tel-00529472.
Testo completoLacroix, Maxine. "Analyse des déplacements permanents des barrages en remblai et en enrochement par des méthodes pseudo-dynamiques pour l'est du Canada". Master's thesis, Université Laval, 2016. http://hdl.handle.net/20.500.11794/27129.
Testo completoMouyeaux, Anthony. "Analyse par éléments finis stochastiques de la fiabilité des barrages en remblai vis-à-vis du risque de glissement". Thesis, Université Clermont Auvergne (2017-2020), 2017. http://www.theses.fr/2017CLFAC002/document.
Testo completoHydraulic works – dams and dikes – are risky civil engineering structures. Dramatic consequences in terms of human and material losses may be induced by their failure. Embankment dams represent an important part of the whole dams in France and the majority of dams worldwide, without considering the important lengths of fluvial and coastal dikes. The structural safety of such structures is traditionally evaluated with limit-state deterministic or semi-probabilistic methods. Nevertheless, French regulations regarding hydraulic works has recently evolved and now impose for all large dams the realization of risk assessment studies based on probabilistic approach. In this purpose, the principal objective of this thesis work is to develop a probabilistic approach to evaluate earth dam reliability concerning the sliding mechanism, which is one of the designing limit-state of such structures. Three scientific issues have to be treated for developing such approach: · elaboration of an hydro-mechanical model for the dam deterministic evaluation towards sliding mechanism; · probabilistic modeling of hydraulic and mechanical soil properties spatial variability; · mechanical-reliability coupling with integration of the spatial variability representations in the hydro-mechanical model. Some research studies already exist on these issues. However these works concern generally only a part of the general issue: the lack of global work is to be deplored. Our work proposes a global methodologic approach taking into account the whole scientific issues and applying hydraulic and mechanical modeling approaches based on real data available in the earth dam. The developed approach is then applied on a dam case study. Hydro-mechanical model uses finite element method and is developed with the user-free code Cast3M which is compatible for a research use. This code allows the safety factor calculation through the strength reduction technique with integration of the pore pressures field estimated in transient condition. The spatial variability of embankment properties is represented with random fields based on a geostatistical analysis of construction controls data. These random fields are then integrated into the finite element model. A coupling between the physical finite element code Cast3M and the reliability software OpenTURNS finally allows assessing the uncertainties propagation and the reliability evaluation of the studied dam
Chau, Ngoc An. "Analyse de l'influence des caractéristiques mécaniques et hydrauliques sur le comportement des barrages en terre et en enrochement". Grenoble INPG, 1999. http://www.theses.fr/1999INPG0005.
Testo completoCarjaval, Moncada Claudio Andrés. "Evaluation probabiliste de la sécurité structurale des barrages-poids". Clermont-Ferrand 2, 2009. https://hal.archives-ouvertes.fr/tel-01298893.
Testo completoCarbonneau, Charles. "Développement d'une base de donnée [i.e. données] expérimentale sur le comportement dynamique des barrages en béton". Sherbrooke : Université de Sherbrooke, 2000.
Cerca il testo completoTétreault, Pierre-Étienne. "Influence d'une crue sur l'écoulement transitoire à travers un barrage en remblai". Master's thesis, Université Laval, 2019. http://hdl.handle.net/20.500.11794/35008.
Testo completoThe issue of core overtopping in embankment dams during floods caused by failures of water-level control systems is a concern to dam managers. Core overtopping can generate flow velocities far greater than those considered during design and can result in intense flow in zones where no flow was intended. A 2D finite-element numeric model running on the COMSOL Multiphysics 5.3 software platform was generated to evaluate the impact of soil permeability, dam geometry and flood shape on seepage and internal flow systems. This numerical model was used to conduct a series of sensitivity analyses on a conceptual standard dam. These analyses have shown the importance of crest and core permeability and maximum height reached by the flood on the rate at wich core overtopping occurs and on erosion velocities generated. Contact erosion based on the Brauns (1985) criteria did not seem to be a concern for these sensitivity analyses as opposed to internal erosion based on the Konrad & Côté (2013) criteria which seemed highly probable. Subsequently, a case-study on an existing Hydro- Québec earthfill dam was also carried out. Because of the high permeability of the crest components of this structure, significant velocities and turbulent flow could be obtained in the crest material in cases of high floods, without however being problematic in terms of contact erosion. Furthermore, numerical convergence of the model has been greatly improved by using the van Genuchten-based (1980) water retention curves instead of the Brooks & Corey-based (1964) curves.
Yaseri, Alireza. "Analysis of earth dam-flexible canyon interaction by 3D hybrid FEM-SBFEM". Doctoral thesis, Université Laval, 2021. http://hdl.handle.net/20.500.11794/70281.
Testo completoThe canyon surrounding a dam can be assumed as an unbounded domain, and the geometry and flexibility of a canyon are parameters that greatly affect the values of natural periods in earth dams. In this thesis, in order to take into account these two effects, canyons are modeled by SBFEM, and earth dams, which have limited geometries, are modeled by FEM. The hybrid FEM-SBFEM technique used for the dynamic three-dimensional analysis of soil-earth dam interactions is validated with results available in the literature. Because the dynamic-stiffness matrix of the unbounded domain is complex and frequency-dependent, the classical mode-superposition method is not straightforward for a soil-structure interaction system, and thus, to obtain their fundamental natural frequencies, the modeled dams were excited in the upstream-downstream direction. The natural periods of earth dams in canyons with different geometries shapes and impedance ratios are obtained, and are found to have significant effects on the dams’ natural periods. The results are compared with actual recorded data, and it is found that the graphs put forward in this study may be used by practical engineers for the estimation of natural periods of earth dams in canyons with different shapes and material properties. Several amplification functions corresponding to different canyon conditions are obtained by applying a uniform displacement at the canyons’ boundaries. A comprehensive study is performed to examine the effects of canyon geometry and flexibility on the steady-state responses of the dams, and it is found that these two effects significantly influence the amplification functions. While the flexibility of the canyon does affect the maximum amplification function value, this value does not change for earth dams in canyons that have different shapes but the same length. In addition, the lateral responses of earth dams in the time domain are computed in order to analyze the aforementioned effects under an actual earthquake. The proposed amplification functions are used to compare the recorded response spectra of the El Infiernillo dam under the two 1966 earthquakes with the calculated amplification function, and a reasonable agreement is observed between them. The equivalent linear method (EQL) is implemented into the FEM, and the FEM-SBFEM technique is extended in order to take into consideration the effect of earth dams’ nonlinear behavior. It is observed that such nonlinear behavior greatly affects the natural frequency, the amplification function, and peak crest acceleration of earth dams located in canyons. The effects of canyon geometry and flexibility on the nonlinear behavior are examined, and it is found that by increasing canyon flexibility, the effect of nonlinearity is decreased. The El Infiernillo dam is modeled by the 3D nonlinear FEM-SBFEM, and comparison of the crest amplification function obtained by the proposed method with the recorded data shows the accuracy of the nonlinear FEM-SBFEM.
Couturier, Bernard. "Les études géologiques dans les projets de barrages". Phd thesis, Grenoble 1, 1987. http://tel.archives-ouvertes.fr/tel-00785561.
Testo completoCurt, Corinne. "Evaluation de la performance des barrages en service basée sur une formalisation et une agrégation des connaisssances". Clermont-Ferrand 2, 2008. http://www.theses.fr/2008CLF21819.
Testo completoCôté, Stéphane. "Critères de stabilité interne pour des matériaux de faible plasticité soumis à l'écoulement de l'eau". Thesis, Université Laval, 2010. http://www.theses.ulaval.ca/2010/27459/27459.pdf.
Testo completoOuld, Hamoni Mohamed Abderrahmane. "Détection des fuites d'eau dans les barrages en terre par polarisation spontanée : détermination expérimentale du potentiel zêta et du coefficient de couplage". Mémoire, Université de Sherbrooke, 2013. http://hdl.handle.net/11143/6201.
Testo completoKourdey, Alaa. "Une approche mixte (numérique/équilibre limite) pour le calcul de stabilité des ouvrages en terre : développement et application aux barrages et talus miniers". Vandoeuvre-les-Nancy, INPL, 2002. http://www.theses.fr/2002INPL044N.
Testo completoDe, Freitas Maciel Geraldo. "Contribution expérimentale et théorique à l'étude des ondes produites par des glissements solides dans des retenues de barrages". Grenoble 1, 1991. http://www.theses.fr/1991GRE10166.
Testo completoSabor, Kawtar. "Couplage de mesures géophysiques pour la reconnaissance des digues en terre : application du data mining". Electronic Thesis or Diss., Sorbonne université, 2020. http://www.theses.fr/2020SORUS089.
Testo completoIn France, EDF (electricity of France) operates more than 500 km of dykes that are part of its hydroelectric power plants. The water in the stream is diverted into an open channel bordered by earthen dykes. Within the framework of the regulations on hydraulic safety and the reinforcement work carried out on hydraulic structures, several monitoring methods are used, ranging from visual inspection and archive research to in-situ geotechnical measurements and laboratories. However, geotechnical measurements are destructive to the structure and provide localized point information about the prospected portion, which is why geophysical measurements were used. These measurements are used to characterize in a "quasi-continuous" way important linear structures while preserving their state thanks to the "non-destructive" nature of these methods. EDF thus works on the use of geophysical methods for the recognition and the monitoring of its structures. However, the interpretation of the geophysical profiles is subjective to the knowledge of the person who interprets it because of the smoothing introduced by the inversion. To be able to use the results of these methods in a regulatory framework, it is therefore necessary to know their limits of use and to objectify the interpretations of the inversion results. This brings us back to the present thesis work. In the framework of my work, I propose an approach of automatic interpretation of inverted profiles using a clustering algorithm from data mining. This approach is also used to couple different geophysical measurements in order to improve the interpretations. In order to define the approach to apply clustering in geophysics and to verify the feasibility of this approach for the interpretation of geophysical measurements, I followed a validation methodology which consists in applying my approach on synthetic models and then testing it on field data from a metaphysical measurements campaign that I carried out during my thesis. The different steps of validation allowed me to set up a methodology of application of clustering to interpret the geophysical measurements but also to raise new questions which must be treated in the perspectives of my work
Brault, Jean-Simon. "Développement d'une cellule de conductivité hydraulique permettant d'évaluer l'anisotropie des tills compactés du nord québécois". Thesis, Université Laval, 2010. http://www.theses.ulaval.ca/2010/26917/26917.pdf.
Testo completoCompacted tills are widely use as core of embankment dams in northern Quebec. It is expected that placement method in successive layers may result in a permeability anisotropy different from unity. Various experimental techniques are available to assess the permeability anisotropy for different types of materials. However, these methods have two principal disadvantages: i) the anisotropy rapport is evaluated on separate samples and ii) the experimental procedure could potentially disturb the sample by inappropriate manipulations. In order to improve the characterization of the anisotropy rapport of compacted tills, a new square cell was built. This new cell is able to quantify the anisotropy rapport in both states, saturated and almost saturated conditions. The permeability under vertical and horizontal flow is assessed on a single sample and a new experimental procedure has been developed to minimize preferential seepage paths along the porous stones. Injection of bovine gelatin is used to temporarily seal the porous stones perpendicular to the flow path (unused). Continuous hot water flow is used to extract the gelatin once the permeability testing is done. This new device and procedure have been successfully tested to evaluate the effect of placing method and stone content on the permeability anisotropy of compacted tills. For an analysis in quasi-saturated state, the anisotropy rapport is greater than 3 or 7 for a dry compaction. On the wet side, the anisotropy rapport is close to one. However, the procedure developed in the saturated condition should be used to confirm these results. In conclusion, this project has helped to build a useful tool to quantify the anisotropy rapport of tills, an important issue in the evaluation of embankment dams. Key words: permeability, anisotropy, square permeability cell, compacted tills, embankment dam.
Bonelli, Stéphane. "Contribution à la résolution de problèmes élastoplastiques de mécanique des sols et d'écoulements non saturés par la méthode des éléments finis". Aix-Marseille 2, 1993. http://www.theses.fr/1993AIX22038.
Testo completoQin, Tong Chun. "Influence of heterogeneity on the hydro-thermal behavior of an embankment dam". Doctoral thesis, Université Laval, 2015. http://hdl.handle.net/20.500.11794/25775.
Testo completoThis thesis contributes to the field of numerical modeling of the influence of heterogeneity on the hydro-thermal behavior of an embankment dam. The layering saturated hydraulic conductivities are estimated by the geostatistical method with the consideration of spatial continuities of fines content, water content and dry density. The lower values of hydraulic conductivities in the downstream portion of the core are provided from the numerical study on the dissolution, transportation, exsolution and diffusion of the gas at the upstream boundary. The predicted saturated hydraulic conductivities as well as the lower value of unsaturated hydraulic conductivities in the downstream portion are used as input parameters in the numerical simulation of heterogeneous influence. Five parametric studies performed with presence of one or more layers within the core with increased values of hydraulic conductivity are simulated in numerical models to investigate the influence from variable values of hydraulic conductivities as well as the changing locations and thickness of pervious layers on the thermal response. The numerical model also simulates the monthly thermal response of the core, which reveals the existence of another more pervious zone in the lower portion of the core.
Houdard, Clément. "Analyse de solutions pour limiter l'érosion externe du talus arrière d'une digue en terre soumise à la houle : une approche basée sur la théorie des copules et l’analyse de sensibilité globale". Electronic Thesis or Diss., Université Gustave Eiffel, 2023. http://www.theses.fr/2023UEFL2070.
Testo completoThis study presents a comprehensive analysis framework for an earthen dyke located in Camargue, France, which is regularly subjected to erosion on the landward slope. The aim of the study is to improve the resilience of the dyke by providing a reliable model of damage frequency. To achieve this, we developed a system that combines copula theory, empirical wave propagation, and overtopping equations, as well as a global sensitivity analysis. The system provides the return period of erosion damage on a set dyke and recommendations for dyke reinforcement and model self-improvement. The global sensitivity analysis requires calculating a high number of return periods over random observations of the tested parameters. This provides a distribution of the return periods and a more general approach to the behavior of the dyke. The results show a return period peak around the two-year mark, which is close to reported observations. However, the distribution is skewed, and the mean value is less reliable as a measure of dyke safety. The global sensitivity analysis results show that no particular category of dyke features contributes significantly more to the uncertainty of the system. The highest contributing factors are the dyke height, the critical velocity, and the coefficient of seaward slope roughness. These results underline the importance of good dyke characterization to improve the predictability of return period estimations. The obtained return periods have been confirmed by current in-situ observations, but the uncertainty increases for the most severe events due to the lack of long-term data. Some improvements to the system have been explored for future use
Lavedan, Gérard. "Aménagement hydroélectrique de Turkwel en bordure du rift - Kenya : contribution du génie géologique à la conception et aux travaux de l'aménagement souterrain". Grenoble 1, 1991. http://www.theses.fr/1991GRE10145.
Testo completoCastonguay, Vincent. "Comportement du till de Romaine 3 soumis à des sollicitations cycliques". Thesis, Université Laval, 2014. http://www.theses.ulaval.ca/2014/30648/30648.pdf.
Testo completoThe resistance of Romaine 3 till was studied under cyclic loading using a new cyclic simple shear apparatus. The tests were carried out at different compaction water contents (dry and wet sides of Proctor optimum) and at different cyclic shear stress levels. It was found that ten times more cycles were needed for samples compacted on the dry side of optimum to reach failure than for samples compacted on the wet side of optimum. It was also found that the tests carried out at low cyclic stress ratio took ten times more cycles to reach failure then tests carried out at high cyclic stress ratios. The presented research project is part of the NSERC – Hydro-Québec Industrial Research Chair in life cycle optimisation for embankment dams.
Liu, Zhenzhen. "Hydro-mechanical analysis of breach processes due to levee failure". Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM4726/document.
Testo completoThe failure of embankment dams and levees can have serious consequence in floodplains. Hydro-mechanical analyses of the breach processes were conducted to develop the accurate estimation of the failure of embankment dams and levees. Considering the internal erosion process, a pipe enlargement model was proposed to simulate the failure of embankment dams and levees by concentrated leak erosion. In this model, the turbulent pipe flow with erosion mechanism was employed as well as the soil erosion law. Considering the breach enlargement process, a simple headcut migration model based on the soil tensile strength was presented to simulate the critical length of the headcut. Good agreements were obtained by comparing with the limit equilibrium numerical model. A simple model was eventually proposed to simulate the lateral shear stress on the breach sides, accounting for the secondary flow. The lateral shear stress can be greater than the bottom shear stress, depending on the situation. . Finally, a large-scale test of dam failure was simulated by using the pipe enlargement and some components of the breach widening models proposed. The simulation of the pipe enlargement process had good agreement with the measured data. Both of the pipe diameter and the discharge flow were well simulated. The stepwise enlargement of the breach width was also well simulated at the beginning of the breach widening process. Validation and application prospects of the proposed models are discussed
Alboresha, Rafid. "Evaluation of the impact of a cavity upon an earth dike (analytical and numerical approaches) : Application to the Val d'Orléans area (France)". Thesis, Université de Lorraine, 2016. http://www.theses.fr/2016LORR0025/document.
Testo completoThe objective of this thesis is to study the interaction mechanisms between a cavity resulting from a karst collapse and a fluvial dike. The question that arises here is to evaluate the potential role of cavities beneath the dikes and their impact on the dike stability in normal and extreme flood conditions. Therefore, the first main point of the present work is to create a method to assess the influence of a dike on the stability of a cavity beneath it. Thereafter the second main point is to evaluate the stability of the dike slope when a cavity appears underneath without taking into account the collapse of the cavity. To achieve the objectives of the thesis, the dike effect on the cavity stability was investigated by studying the influence of the cavity location relatively to the dike and the interaction mechanisms, in the way to prioritize the geometric and geotechnical parameters for a better evaluation of the risk of dike failure. Numerical and analytical approaches were used. An application is described based on the in situ observations and data for the Val d’Orléans area (France). This area is protected against the Loire’s floods by 52 km of earth dikes (levees), in this area, more than 600 karstic sinkholes from 0.5 to 20 m diameter have been identified. The first results of the analytical method show that the cavity instability can significantly increase when the cavity is located under the centre of the dike, and this can affect the stability of the dike when the cavity is sufficiently close to it. We also show that there is a significant effect of the cavity on the dike slope stability, especially in the saturation state (i.e. during extreme floods): cavity collapse can then contribute to dike collapse. A nonlinear numerical modeling (2D and 3D) was used to validate the analytical approach, and to highlight the influence of the different geometrical and geotechnical parameters of the dike and the cavity. The results of the numerical modeling confirmed those of the analytical method. As operational conclusion, the results of the analytical model can be used to help assessing hazard due to the dike collapse taking into account the likelihood of an existing cavity, its position and diameter, and the thickness of the alluvium layer, regarding the data from the Val d’Orléans area
Mouali, Lila. "Etude expérimentale et numérique du comportement hydromécanique des sols résiduels tropicaux : application à la modélisation sismique d'un barrage en remblai aux Antilles". Thesis, Aix-Marseille, 2021. http://www.theses.fr/2021AIXM0606.
Testo completoThe use of residual tropical soils for the construction of embankment dams is an important issue. Dams located in tropical regions are often subject to seismic risk. Most often, foundations with weak characteristics are purged and replaced with compacted soils. Thus, the seismic behavior of the dams located in these regions depend on the dynamic properties of the compacted residual soils. The evaluation of the seismic behavior of a dam is based on the capacity of the models to predict the evolution of the rigidity of the structure during the seismic stress. It is therefore important to have models allowing to predict the shear modulus at small strains, the reduction curve of the normalized shear modulus and the damping curve. The objectives of our research work are to contribute to the improvement of the knowledge of the cyclic mechanical behavior of compacted residual tropical soils and to propose models making it possible to predict their behavior. To answer these, an experimental study of the cyclic properties of soils sampled from the site of a dam under construction in the French West Indies was carried out using undrained cyclic triaxial test objectives and resonant column tests. It is thus shown that the existing equations in the literature are not adapted to our experimental results. Predictive equations for the determination of Gmax, G / Gmax and D are developed. On the basis of the results obtained, nonlinear dynamic numerical simulations were obtained at the scale of the sample and of the structure using the flac software
Randrianasolo, Rindra Annie. "Généralisation de l'approche d'ensemble à la prévision hydrologique dans les bassins versants non jaugés". Electronic Thesis or Diss., Paris, AgroParisTech, 2012. http://www.theses.fr/2012AGPT0083.
Testo completoFlood forecasting is a complex hydrological task: there are numerous uncertainties in the hydrological modelling process, in the determination of the initial catchment conditions before launching the forecast, and in the evolution of future weather conditions. In ungauged catchments, where streamflow observations are incomplete or absent, these uncertainties are even greater, and the need to reduce them becomes essential.This thesis focuses on simple and robust methods that can provide relevant information to quantify the uncertainty in ungauged catchments. The aim is to study the best strategy to search for information in gauged "donors" basins and to transfer it to the ungauged site. We investigate what information is needed to set up a rainfall-runoff model and to perform forecast updating in real time. These two components of a flood forecasting system are thus decoupled in our approach.This thesis is based on a large database of about 1000 French catchments, which includes a key set of 211 catchments that are used to validate the developed approaches. It also relies on an archive of about 4.5 years of ensemble forecasts of rainfall, which are used for hydrological modelling on a daily time step. The methodology adopted here integrates the scenarios of regional transfer of information and the scenarios of weather forecasting together in a forecasting system for ungauged basins. The approach of ensemble forecasting is thus generalised to this particular case of hydrological forecasting. Using several scenarios of future flows, we seek to quantify the predictive uncertainty in ungauged sites.To evaluate the flow forecast scenarios of the hydrological ensemble prediction system, a diagnostic framework with several numerical and graphical criteria is developed. Special attention is paid to the attributes of "reliability" and "accuracy" of the forecasts. We propose a new graphic criterion, named "diagram of ensemble accuracy". This criterion allows to highlight the quality of forecasts that are not necessarily reliable, but are accurate.The results show that forecast reliability in ungauged sites can be improved by using several sets of parameters from neighbour catchments. If on the one hand the variability brought by the information from the geographical proximity influences the spread of the ensemble forecasts, and thus improves forecast reliability, on the other hand taking into account the physical characteristics of the catchments, especially the surface, emerged as an interesting alternative, as it positively influences also the accuracy of the forecasts at the ungauged site.It is also shown that the accuracy of ensemble forecasts at ungauged sites can be improved with the transfer of updating information from gauged neighbour catchments (forecasting updating is here characterized by the assimilation of the last discharge observation in the hydrological model before the time of forecast). The updating information transferred to the ungauged site is the correction applied to the routing reservoir of the hydrological model. Different measures of forecast performance showed that the best option to improve forecast accuracy is to consider the corrections made at the closest gauged site. Kriging also gave satisfactory results, with additionally a positive impact also on the reliability of the ensemble flow forecasts
Randrianasolo, Rindra Annie. "Généralisation de l'approche d'ensemble à la prévision hydrologique dans les bassins versants non jaugés". Phd thesis, AgroParisTech, 2012. http://pastel.archives-ouvertes.fr/pastel-00954967.
Testo completoGoyette, Jean-Olivier. "Influence des flux anthropiques de nutriments et des caractéristiques du territoire sur la qualité de l'eau : une perspective historique du bassin du Saint-Laurent". Thèse, 2018. http://hdl.handle.net/1866/20778.
Testo completoGaspar, Ana Pimentel Torres. "Contribution to control uncertainties in numerical modelling of dam performances: an application to an RCC dam". Doctoral thesis, 2014. http://hdl.handle.net/1822/35837.
Testo completoThe use of fully probabilistic approaches to account for uncertainties within dam engineering is a recently emerging field on which studies have been mostly done concerning the safety evaluation of dams under service. This thesis arises within this framework as a contribution on moving the process of risk analysis of dams beyond empirical knowledge, applying probabilistic tools on the numerical modelling of a roller compacted concrete (RCC) dam during its construction phase. The work developed here aims to propose a methodology so as to account for risks related to cracking during construction which may compromise the dam’s functional and structural behaviour. In order to do so, emphasis is given to uncertainties related to the material itself (i.e. strength, water-to-cement ratio, among others) as well as to ambient conditions during the construction phase of RCC dams. A thermo-chemo-mechanical model is used to describe the RCC behaviour. Concerning the probabilistic model, two aspects are studied: how the uncertainties related to the input variables are propagated through the model, and what is the influence of their dispersion on the dispersion of the output, assessed by performing a global sensitivity analysis by means of the RBD-FAST method. Also, spatial variability of some input parameters is accounted for through bi-dimensional random fields. Furthermore, a coupling between reliability methods and finite element methods is performed in order to evaluate the cracking potential of each casted RCC layer during construction by means of a cracking density concept. As an important outcome of this applied research, probability curves for cracking density within each casted layer as functions of both age and boundary conditions are predicted, which is believed to be an original contribution of this thesis. The proposed methodology may therefore be seen as a contribution to help engineers understand how uncertainties will affect the dam behaviour during construction and rely on it in the future to improve and support the design phase of the dam project.
A aplicação de métodos probabilísticos para o estudo de incertezas no ramo da engenharia de barragens é um campo em crescente ascensão no qual a grande maioria dos estudos realizados se concentra na avaliação da segurança de barragens durante o período de serviço. Este trabalho de tese situa-se neste contexto, pretendendo contribuir para a abordagem de análise de risco em barragens em betão compactado com cilindros (BCC) durante a fase de construção. Assim, é proposta uma metodologia na qual são tidos em conta riscos relacionados com a fissuração do BCC durante a sua construção, o que poderá comprometer o comportamento funcional e estrutural da barragem. As incertezas consideradas integram algumas propriedades do material (i.e. resistência, rácio água-cimento, entre outras) bem como as condições climatéricas que se observam durante a fase de de construção de barragens em BCC. Para descrever o comportamento do BCC é utilizado um modelo termo-químico-mecânico. O modelo probabilístico considera, por um lado, a propagação das incertezas relacionadas com as variáveis de entrada e, por outro, permite avaliar qual a influência que têm na dispersão da resposta do modelo. Essa influência é avaliada através de uma análise de sensibilidade global, recorrendo ao método RBD-FAST. A variabilidade espacial de alguns parâmetros de entrada é também tida em conta através de campos aleatórios bi-dimensionais. O acoplamento entre métodos de fiabilidade e elementos finitos permite avaliar o potencial de fissuração de cada camada de BCC durante a construção da barragem. Para tal é introduzido o conceito de densidade de fissuração. Esta abordagem constitui uma contribuição original, com a obtenção de curvas de probabilidade para a densidade de fissuração, avaliadas ao nível de cada camada e em função da idade e condições de fronteira. A metodologia desenvolvida constitui uma contribuição para a compreensão da influência de determinadas incertezas no comportamento da barragem durante a sua construção, podendo servir no futuro como um importante suporte à fase de projecto de barragens.
Contribution pour le controle des incertitudes dans la modelisation numerique de la performance de barrages. Application a un barrage en BCR. L’application des approches probabilistes pour tenir compte des incertitudes dans le domaine des barrages est un sujet en developpement. Cependant, la plupart des etudes ont ete realisees sur l’evaluation de la securite des barrages pendant leur service. Ce travail de these vise a appliquer ce type d’approches et a faire une contribution a l’analyse de risque des barrages en beton compacte au rouleau (BCR) des sa construction, a l’aide d’une simulation numerique. Les travaux presentes dans ce manuscrit proposent l’application d’une methodologie qui vise a quantifier la vulnerabilite vis-a-vis de l’apparition de la fissuration pendant la construction du barrage, ce qui peut aflecter a long-terme la permeabilite et par consequent, compromettre son comportement structurel. Pour ce faire, l’accent est mis sur les incertitudes liees a quelques caracteristiques des materi- aux (e.g., resistance, rapport eau-ciment, entre autres) et aux conditions environnementales pendant la phase de construction. Un modele thermo-chemo-mecanique est utilise pour decrire le comportement du BCR. En ce qui concerne le modele probabiliste, deux aspects sont etudies: i) comment les incertitudes liees aux variables d’entree sont propagees dans le modele, et ii) quelle est l’influence de leur dispersion par rapport a la dispersion totale de la sortie. Ce dernier est evalue par l’intermediaire d’une analyse de sensibilite globale eflectuee avec la meth- ode RBD-FAST. En outre, la variabilite spatiale des parametres d’entree est aussi prise en compte a travers des champs aleatoires bidimensionnels. Par ailleurs, un couplage entre des methodes de fiabilite et la methode d’elements finis est eflectue de facon a evaluer le potentiel de fissuration dans chaque couche de BCR lors de sa construction en utilisant un concept de densite’ dc fissumtion. Comme resultat important issu de ce travail de recherche, des courbes de probabilite pour la densite de fissuration sont obtenues au niveau de chaque couche en fonction de leur age et des conditions aux limites, ce qui est considérée comme étant une contribution originale de cette these. La méthodologie proposée peut etre utilise pour aider a comprendre comment les incerti- tudes vont affecter le comportement du barrage pendant sa construction et servir d’appui dans le futur pour améliorer et soutenir la phase de conception du projet de barrage. Mots-clés: Barrages BCR, Comportement thern1o-chemo-nqécanique, Incertitudes, Meth- odes de fiabilité, Analyse de sensibilité, RBD-FAST, Champs aléatoires.
The financial support by the Portuguese Foundation for Science and Technology (FCT) PhD grant (SFRH/BD/63939/2009, QREN POPH - Tipologia 4.1).