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CHUQUIMUNI, ROBERTH APOLINAR AGUILAR. "NUMERICAL ANALYSIS OF RAISING EARTH DAMS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2005. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=8624@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROUma das atividades relacionadas à recuperação de barragens envolve o alteamento de barragens existentes, normalmente com o objetivo de aumentar a capacidade de armazenamento dos reservatórios, melhorar o fator de segurança dos taludes ou a proteção da estrutura contra possíveis cheias. O alteamento pode estar previsto no projeto original da barragem, mas na maioria dos casos trata-se de um novo estudo, com a barragem em operação, devendo-se verificar as novas condições de fluxo, efeitos na estabilidade de taludes e na resposta da barragem a carregamentos estáticos e sísmicos, estes principalmente em regiões de alta sismicidade, como no sul do Peru, onde se enontram a barragem de terra de Viña Blanca, aqui considerada. Nesta dissertação o método dos elementos finitos e o método de equilíbrio limite, isolada ou conjuntamente, são empregados para análise estática e dinâmica destas barragens de terra considerando diversas opções de alteamento, como a construção de muros parapeito, muros de gabião, solo compactado, solo reforçado com geotêxteis e solo reforçado com revestimento de concreto. De estudos de perigo sísmico efetuados no local das barragens, selecionou-se o valor de aceleração horizontal máximo para ser utilizado nos registros de aceleração ocorridos nos terremotos de Lima (1974) e de Moquegua (2001). As análises numéricas efetuadas mostram que as opções de alteamento consideradas não alteram significativamente as condições de segurança das barragens existentes, tanto do ponto de vista hidráulico como da estabilidade de taludes e resposta dinâmica durante a incidência de terremotos.
One of the activities related to dam constructions involves the raising of the existent structure, normally done with the objective of increasing the water storage capacity of the reservoirs, improving the safety factor of the embankment slopes or to ensure a better protection against possible water flooding. The raising of an earth dam can be predicted in the original dam plan, but in mostly situations consists of a new design, with the dam fully operational, where the effects of a new dam height and reservoir level should be assessed with respect to flow conditions, stability of the embankment soil slopes and the response of the revised structure under static and seismic loads, mainly in highly seismic regions, as in the South of Peru where the earth dam of Viña Blanca, herein studied, was constructed. In this dissertation, the finite element method and the limit equilibrium method were used for the static and dynamic analyses of these earth dams, in their original geometry as well after dam raising with reinforced soil, compacted soil and concrete or gabion structures, among other options. From studies of seismic risk analyses carried out at the dam sites, the value of maximum horizontal acceleration equal to 0.4g was chosen to be used as the peak acceleration in the Lima (1974) and Moquegua (2001) acceleration time histories. The numerical results indicate that all dam raising options investigated in this work do not affect the safety conditions of the dams significantly, either under the point of view of the hydraulic behavior as well as soil slope stabilities or the dynamic response of the earth dams to seismic loads.
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Morris, Mark William. "Breaching of earth embankments and dams." Thesis, Open University, 2011. http://oro.open.ac.uk/54530/.
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Despite 'modern' construction and management techniques, flood embankment and embankment dam failures occur almost routinely around the world. The need to understand, predict and prevent the breaching process remains a high priority for owners and flood risk managers alike. This research provides new understanding and improved methods for predicting breach initiation and growth through earth flood embankments or dams. The improvement of breach model accuracy has made slow progress over the past 20 years, with confusion around breaching processes arising from a lack of appreciation of soil mechanics interacting with hydraulics and structural behaviour. The prediction of different breach processes requires the integration of techniques from all three disciplines. This thesis makes advances from earlier work (Mohamed, 2002) to produce a predictive breach model intended for industry application. The research develops improved approaches for flow calculation, sediment erosion and structural response for predicting breach initiation and growth and uses field data, including video footage, from the EU IMP ACT project and large scale test and case study data from collaboration with the International Dam Safety Interest Group breach modelling project.
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Pelecanos, Loizos. "Seismic response and analysis of earth dams." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/23649.
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Many earth dams around the world are located in zones characterised by moderate to high seismicity. Their seismic stability can be particularly critical for the safety of the areas in the downstream side and therefore an in depth understanding of their response during earthquakes is required. This thesis describes a numerical study related to both the seismic response and analysis of earth dams using the finite element method. In the first part of the thesis, the effect of the upstream reservoir hydrodynamic pressures on the elastic seismic response of dams is explored. Firstly, a methodology is proposed in which the reservoir domain is modelled with finite elements focusing in particular on the accurate prediction of the hydrodynamic pressures on the upstream dam face. Secondly, a parametric study of dam-reservoir interaction is carried out to examine the effect of the reservoir on the seismic response of dams. The second part of the thesis is concerned with the nonlinear seismic behaviour of earth dams. Firstly, a well-documented case study, the La Villita dam in Mexico, is analysed in order to validate the numerical model and a good agreement is obtained between the recorded and predicted data. Subsequently, using as a reference the calibrated model, parametric studies are performed in order to obtain a better insight into the dynamic response and analysis of earth dams. The latter studies provide a means to assess the effect of different modelling considerations on the seismic analysis of dams.
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Lau, Tak Chi. "Fully-coupled earthquake response analysis of earth dam including anisotropic effect /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202008%20LAU.
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Chi, Fengdong. "Probabilistic Analysis of Internal Erosion in Earth Dams." Electronic Thesis or Diss., Université Clermont Auvergne (2021-...), 2024. http://www.theses.fr/2024UCFA0041.
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Les barrages sont des ouvrages induisant des risques significatifs, dont leur rupture peut entraîner des conséquences dramatiques en termes de pertes humaines et matérielles. L'érosion interne représente une préoccupation majeure, étant responsable de près de 50 % des défaillances des barrages en terre. Traditionnellement, l'évaluation de la sécurité structurelle de ces ouvrages reposait sur des méthodes déterministes ou semi-probabilistes. Plus récemment, des approches probabilistes ont été développées pour analyser les risques associés aux barrages. Néanmoins, évaluer le mécanisme d'érosion interne des barrages reste un défi en raison des incertitudes liées à l'évaluation des contraintes hydrauliques dues aux écoulements internes aux ouvrages et à l'évaluation des propriétés de résistance des sols.Dans ce contexte, l'objectif principal de cette thèse est de développer une approche probabiliste pour évaluer la fiabilité des barrages en remblai concernant le mécanisme d'érosion interne. Cette étude se concentre principalement sur les aspects suivants : 1) l'établissement d'un modèle hydraulique probabiliste spacialisé à partir de champs aléatoires pour représenter les écoulements au sein d'un barrage en remblai, prenant en compte les différentes incertitudes des propriétés de résistance des sols, 2) la proposition d'une analyse probabiliste pour l'initiation du mécanisme d'érosion régressive au sein d'un barrage en remblai et 3) la proposition d'une analyse complète des mécanismes d'érosion interne, en les appliquant à un cas concret de barrage, afin d'évaluer la sécurité vis-à-vis de l'érosion interne, en prenant en compte différents mécanismes d'érosion tels que : l'érosion régressive, la suffusion et l'érosion par contact.Le manuscrit de cette thèse représente une contribution précieuse aux études probabilistes existantes sur les barrages en remblai. Il fournit aux scientifiques et aux ingénieurs des informations utiles sur les résultats obtenus, facilitant ainsi une résolution plus efficace des problèmes géotechniques concrets dans un cadre probabilisteDams are structures involving significant risks. The failure of a dam can lead to dramatic consequences in terms of human and material losses. Internal erosion is a major concern, responsible for almost 50% of earth dam failures. Traditionally, the assessment of the structural safety of these structures was based on deterministic or semi-probabilistic methods. More recently, probabilistic approaches have been developed to analyze the risks associated with dams. However, evaluating the internal erosion mechanisms of dams remains a challenge due to the uncertainties linked to the evaluation of hydraulic stress due to seepage and the evaluation of the soil strength properties to internal erosion.In this context, the main objective of this thesis is to develop a probabilistic approach to assess the reliability of embankment dams regarding the internal erosion mechanism. This study mainly focuses on the following aspects:1) the establishment of a probabilistic hydraulic model spatialized from random fields to represent the flows within an embankment dam, taking into account the different uncertainties in the resistance properties of the soil, 2) the proposal of a probabilistic analysis for the initiation of the backward erosion mechanism within an embankment dam and 3) the proposal of a complete analysis of the internal erosion mechanisms by applying them to a real dam case in order to assess the safety against internal erosion, taking into account different internal erosion mechanisms such as backward erosion, suffusion and contact erosion.This thesis manuscript represents a valuable contribution to existing probabilistic studies of embankment dams. It provides scientists and engineers with useful information on the results obtained, thus facilitating more efficient resolution of practical issues within a probabilistic framework
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Ersayın, Deniz Tayfur Gökmen. "Studying Seepage In A Body Of Earth-Fill Dam By (Artifical Neural Networks) Anns/." [s.l.]: [s.n.], 2006. http://library.iyte.edu.tr/tezler/master/insaatmuh/T000350.pdf.
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Yan, Liping. "Seismic deformation analysis of earth dams : a simplified method." Diss., Pasadena, Calif. : California Institute of Technology, 1992. http://resolver.caltech.edu/CaltechETD:etd-08202007-094107.
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MURRUGARRA, DENYS AMADOR PARRA. "NUMERICAL MODELING OF THE STATIC AND SEISMIC BEHAVIOR OF EARTH DAMS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1996. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=2020@1.
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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIORO presente trabalho apresenta o desenvolvimento de um procedimento numérico para a análise sequencial estática e dinâmica de barragens de terra, durante as principais fases da vida da estrutura:construção, enchimento do reservatório e carregamentos sísmicos. A modelagem numérica é feita mediante o método dos elementos finitos, incorporando as não linearidades dos materiais através de módulos dependentes do nível de tensões, para a análise estática, e do nível de deformações para a análise dinâmica. Inicialmente são apresentadas as características do comportamento de barragens de terra submetidos a carregamentos estáticos e dinâmicos. Apresentam-se também alguns dos fatores que influenciam a resposta estática e dinâmica deste tipo de estrutura geotécnica. Em seguida apresentam-se as formulações e implementações numéricas realizadas para a análise sequencial, estática e dinâmica, por elementos finitos. Desenvolveu-se neste trabalho um programa de microcomputador para análise de barragens considerando varias opções como elementos infinitos, elementos de interface, contornos viscosos, etc. Outras obras de terra e problemas geotécnicos, além de barragens, podem também serem analisadas por este programa, de caráter bastante geral. Finalmente ilustra-se a aplicabilidade do programa e procedimentos implementados, através da previsão do comportamento da Barragem de Recreta, localizada no Peru. Os resultados desta análise, considerando no estudo dinâmico o registro disponível do terremoto de Lima (1974), são apresentados e discutidos.
This work presents the development of numerical procedures for static and dynamic sequential analysis of earth dams during the main phases of their life: construction, reservoir filling and seismic loading. The numerical modeling is performed using the finite element method with material modulus that exhibit either stress state (static analysis) or strain state (dynamic analysis) dependency. General behavior characteristics of earth dams subjected to static and dynamic loads are initially presented. The main factors influencing the static and dynamic responses are also indicated e briefly discussed.Mathematical formulations and the numerical algorithms considered in the development of a computer code specially written for this research, such as interface elements, infinite elements, viscous boundaries, etc., are fully described with several illustrative examples to validate their application. The prediction of both static and dynamic responses of the Recreta Dam, in Peru, is also carried out considering the available seismic records of the Lima earthquake, occurred in 1974. The computed numerical results indicate that the computer program is reliable, efficient and potentially useful for other geotechnical applications.
Este trabajo presenta el desarrollo de un procedimiento numérico para el análisis secuencial estático y dinámico de dique de tierra, durante las principales fases de la vida de la extructura:construción, llenado del reservatorio y cargas sísmicas. La modelación numérica se realiza mediante el método de los elementos finitos, incorporando las no linealidades de los materiales a través de módulos dependientes del nível de tensiones, para el análisis estático, y del nível de deformaciones para el análisis dinámico. Inicialmente se presentan las características del comportamiento de dique de tierra sometidos a sobrecargas estáticas y dinámicas. Se presentan también algunos de los factores que influyen en la respuesta estática y dinámica de este tipo de extructura geotécnica. En seguida se presentan las formulaciones e implementaciones numéricas realizadas para el análisis secuencial, estático y dinámico, por elementos finitos. Se desarrolló en este trabajo un programa de microcomputador para el análisis de dique considerando varias opciones como elementos infinitos, elementos de interface, contornos vizcosos, etc. Otras obras de tierra y problemas geotécnicos, además de dique, pueden también ser analizadas por este programa, de carácter bastante general. Finalmente se ilustra la aplicabilidad del programa y los procedimentos implementados, a través de la previsión del comportamiento del Dique de Recreta, localizada en el Peru. Los resultados de este análisis, considerando en el estudio dinámico el registro disponible del terremoto de Lima (1974), son presentados y discutidos.
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Haeri, Seyed Mohsen. "Response of earth and rockfill dams to strong earthquakes including dam-foundation interaction effects." Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/47094.
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Mehdizadeh, Seyed Amirali. "Hazard assessment of debris flows initiated by breaching of small earth dams." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44033.
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There are many small earth dams perched high above the floor of the Okanagan Valley in British Columbia. These dams pose a potential risk for destructive debris flow generation if they become breached. A relatively small outburst can trigger a much larger volume debris flow downstream of the dam. The failure of the Testalinden dam in the southern Okanagan region in June 2010 clearly demonstrated the destructive power of a debris flow triggered by the water released by a breach through a poorly maintained dam. Homes were destroyed and property was damaged. This thesis presents a methodology for preliminary assessment of potential debris flow initiation hazards caused by the breaching of small earth dams using digital elevation models, available maps, and limited monitoring records of dams. Research can assist dam safety officers in better ranking the consequences of dam failure. Empirical equations are used to predict the peak outflow if a breach occurs in a small earth dam. The creek gradient and the estimated height of water or outflow per unit width in the creek channel resulting from the outflow are used in debris flow initiation criteria to delineate possible locations along a creek where a debris flow may initiate. If debris flow initiation were possible, this would trigger the need for more detailed assessment of dam failure consequences and will likely result in a higher dam failure consequence classification compared to consideration of flooding only.
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Sodeify, Kamran. "Modelling for response analysis of earth dams subjected to travelling surface waves." Thesis, Imperial College London, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295725.
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Elmore, Andrew Curtis 1964. "A finite element investigation of flow through an earth dam with open cracks using thin element technique." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276897.
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The residual flow procedure (RFP) is used to conjunction with finite element method for solution of steady state free surface seepage in dams containing open cracks. The cracks are simulated using the thin-layer element concept. A comprehensive parametric study is performed to analyze the applicability of the numerical procedure with the thin layer element. Here, vertically trending as well as horizontally trending open cracks are considered with variable lengths, widths, and conductivities. It is found that the numerical results involve oscillatory, unstable, and physically unreasonable behavior beyond critical values of the geometry and conductivities. Here, the vertically trending configurations are found to be relatively more sensitive than the horizontally trending configurations. Although additional research will be needed to analyze other factors such as different crack geometries, transient flow, and different ratios of crack conductivities to surrounding soil conductivities, the results presented here suggest that the procedure can be applied for seepage analysis in dams containing open cracks.
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Purssell, Tanis Jane. "Modulus reduction dynamic analysis." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25136.
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A semi-analytical method of dynamic analysis, capable of predicting both the magnitude and pattern of earthquake induced deformations, is presented. The analysis is based on a modulus reduction approach which uses a reduced modulus to simulate the softening induced in soils during cyclic loading. The effects of the inertia forces developed during dynamic loading on the induced deformations are also included through an appropriate selection of the reduced modulus.
The reduced modulus is utilized in a static stress-strain analysis to predict the magnitude and pattern of the deformations induced during earthquake loading. The appropriate modulus reduction is determined from laboratory tests on undisturbed soil samples. Three methods of computing a suitable post-cyclic modulus were investigated but only the cyclic strain approach, in which the modulus is determined from cyclic loading tests that duplicate the field stress conditions, yields reductions of sufficient magnitude to provide realistic estimates of earthquake induced deformations.
The modulus reduction analysis was used to predict the deformations occurring during dynamic loading of a model tailings slope in a laboratory shaking table test and of the Upper San Fernando Dam during the earthquake of February, 1971. These studies showed that the modulus reduction analysis is capable of reproducing the dynamically induced deformations and that reductions in the modulus of up to 1000 times may be required. Unfortunately, limitations of the testing equipment and inadequacies in the available data required that the appropriate modulus reductions could not be determined entirely through laboratory and field investigations. Some assumptions were necessary in selecting the reduced modulus values used in the analyses. Although these case studies were, hence, unable to provide full verification of the proposed method, they do demonstrate the reliability and simplicity of the analysis as a method of assessing the performance of soil structures during earthquake loading.Applied Science, Faculty of
Civil Engineering, Department of
Graduate
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Kakuturu, Sai Prasad. "Modeling and experimental investigations of self-healing or progressive erosion of earth dams /." Search for this dissertation online, 2003. http://wwwlib.umi.com/cr/ksu/main.
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Pereira, Jose Henrique Feitosa. "Numerical analysis of the mechanical behavior of collapsing earth dams during first reservoir filling." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1996. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ32808.pdf.
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Guo, Jinxing. "Stability Analysis of Earth Dams and Dikes under the Influence of Precipitation and Vegetation." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-198977.
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An earth dam and a dike is one kind of hydraulic construction, which is built with highly compacted earth and can be used for the purpose of containing water in a reservoir to secure the water supply, and in flood control. Earth dam and dike can be a safety issue, as it can experience catastrophic destruction due to the slope failure caused by various factors, such as construction materials, vegetation, atmospheric conditions and so on. The aim of this study is to investigate the influence of the saturation degree (or water content) on the stability of earth dam and dikes under the consideration of precipitation and vegetation with the program PCSiWaPro® (developed at the Technical University of Dresden, Institute of Waste Management and Contaminated Site Treatment).
The preliminary tests on a physical model have shown that the security and stability has been already severely compromised in the partially saturated region, i.e. the area above the seepage line was in great danger and it came quickly to landslides on the air side. Before the stability analysis could be done for those unsaturated zones, water flow processes and water saturation in the saturated and partially saturated soil area were simulated using the simulation program PCSiWaPro® under transient boundary conditions. The integration of a weather generator into PCSiWaPro® allows a transient water flow calculation with respect to atmospheric conditions (precipitation, evaporation, daily mean temperature and sunshine duration) and removal of water by plant roots and leaves. Finally, with the Program PCSiWaPro® and Gmsh, a 2D dynamic model of water content distribution in the earth dam could be built, incorporating information of not only climate parameters and vegetation but also geometry, soil properties, geohydraulic conditions and time-dependent boundary conditions. The simulation results of several scenarios both in the laboratory and in the field of China and Germany clearly demonstrated that the accordance between measured values and calculated values for water content using the simulation program PCSiWaPro® was very good.
In addition, two kinds of stability analysis models (the Infinite Slope Model and the BISHOP’S Model, one kind of the limit equilibrium method), which were both developed from the old Mohr-Coulomb Model, have been improved with the additional consideration of root reinforcement in the upper layer of the slope and soil water in the earth slope. The Infinite Slope Model has been proved to be mainly applied for the surficial landslide; while the BISHOP’S Model is more responsible for the deeper slip landslide forecasting. Then based on the PCSiWaPro® simulation result of water content in the unsaturated slope in the earth bodies from two study sites, Fs (safety of factor) calculation for those earth slopes was derived providing a sufficient forecasting system for the slope-failure-flood. The results have been compared with the calculated Fs values from the old models (without consideration of the influence of water content change on the slope stability) to study how significantly water content increased the risk of slope landslides.
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Van, Heerden Jacobus Hendrik Francois. "Direct measurement of pore fluid suction in gold mine tailings." Diss., Pretoria : [s.n.], 2003. http://upetd.up.ac.za/thesis/available/etd-09212005-135324/.
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Soliday, Stanley Jr. "Limits of limit equilibrium and finite element techniques applied to cracked debris dams on collapsing foundations." PDXScholar, 1991. https://pdxscholar.library.pdx.edu/open_access_etds/4428.
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Limits of slope stability, limit equilibrium methods, and of the finite element code FEADAM are reached in the application of these methods to the problem of cracked dams constructed on collapsing soils.
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Biswas, Sharbaree. "Study of cohesive soil-granular filter interaction incorporating critical hydraulic gradient and clogging." Access electronically, 2005. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20060221.100311/index.html.
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McLaughlin, Fraser. "Using regional flow regime classes to identify flow anomalies in a set of Canadian rivers regulated by dams." Thesis, McGill University, 2014. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=123105.
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It is well established that a river's natural flow regime is a key determinant of ecological integrity and that dam regulated-flow releases can in some cases be detrimental to biotic communities (e.g. Poff and Zimmerman, 2010). Regional flow classes, groups of rivers that share similar natural flow regimes (called 'river types' by Poff and Zimmerman (2010)) and to which regional fish communities are adapted, have been proposed (e.g. Poff, 1996; Poff and Zimmerman, 2010; McManamay et al., 2012a) as units of analysis to identify significant damming related flow alteration. Specifically, the natural range of flow behaviour within regional classes can be used to identify the most anomalous flow features in rivers regulated by dams. Through ordination analysis, 5 flow regime clusters were identified based on 70 ecologically important flow indices. These clusters are distinct classes of regional flow regimes for 96 unregulated rivers in proximity to 16 regulated sites chosen as NSERC HydroNet sites in Eastern and Western Canada. The distinguishing characteristics of natural flow regimes within each flow class are explored through visualization in principal component space. The 16 regulated HydroNet sites were assigned to these flow classes through discriminate function analysis based on shared geographic location and watershed characteristics. Anomalous flow features in the regulated rivers are identified and characterized in terms of type and strength by identification of flow indices that are significantly different from observed natural variability in the relevant regional class. We also discuss the potential biological implications of the dominant flow anomalies in this set of rivers regulated by hydro dams.Selon le paradigme du 'Natural Flow Regime', le régime hydrologique naturel (ou régime de débits) d'une rivière est un déterminant clé de son intégrité écologique. L'altération significative de ce régime par un barrage hydroélectrique peut en effet négativement affecter les communautés biotiques d'un écosystème lotique (Poff and Zimmerman, 2010). Récemment, des auteurs influents (e.g. Poff, 1996; McManamay et al., 2012a) ont ainsi proposé qu'afin d'identifier les altérations du régime naturel les plus significatives causés par la régulation par barrage, on utilise un point de référence régional (les 'river type') (Poff and Zimmerman, 2010) constitué de la variabilité présente dans un sous-ensemble de rivières non-régulées coulant dans la région du site régulé, rivières qui partagent naturellement certaines caractéristiques de régime hydrologique (et auxquelles la faune aquatique régionale est adaptée). A cet effet, une analyse d'ordination a été effectuée sur les régimes naturels de débit de 96 rivières non régulées situées à proximité des 16 sites sur rivières régulées par barrage choisis pour étude dans le projet HydroNet, et ce dans deux régions distinctes, l'une dans l'ouest et la seconde dans l'est canadien. Cette ordination, effectuée à partir de 70 métriques de débit reconnus pour leur pertinence écologique, distingue 5 sous-ensembles régionaux de régimes naturels assez distincts (5 'flow classes', sensu McManamay et al., (2012a)) réparties à travers les régions à l'étude. Les caractéristiques contrastantes des régimes de chacune de ces 5 sous-ensembles sont présentées et discutées. Par la suite, une analyse par fonction discriminante permet d'assigner les 16 sites régulés à l'étude à une ou l'autre de ces 5 classes, comme point de comparaison naturel. Cette analyse nous permet par la suite de repérer et de décrire les divers aspects des régimes de débits aux sites régulés qui sont clairement 'hors normes' par rapport à ce qui est observé dans le sous-ensemble régional de référence. Nous discutons brièvement par la suite de certains effets possibles de ces anomalies particulières sur les populations de poisson dans ces écosystèmes.
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Uhacz, Kelly Dean. "Evaluating the role of geogrids in the rehabilitation of cracked dams via numerical techniques." PDXScholar, 1991. https://pdxscholar.library.pdx.edu/open_access_etds/4310.
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Collapse and cracking of debris earth embankment dams is a serious problem in areas of the arid Western United States. The use of geogrids is evaluated in this thesis as a possible solution to prevent or reduce the amount of damage to the structures from collapse and cracking.
An apparatus was designed, constructed, and instrumented to electronically acquire data to evaluate the behavior of geogrids during pullout tests under various normal stresses. The pullout tests were also modelled using numerical techniques to correlate physical test data with numerical test data. Understanding the behavior of the geogrid, in both the physical and numerical pullout tests, allowed the geogrid model to be combined with a collapsing dam model to evaluate the effectiveness of reinforcement at reducing, or preventing, damage caused by collapse and cracking. Results from this model indicate that the effectiveness of the geogrid was minimal. The ineffectiveness of the geogrids, however, may be a result of numerical modelling problems associated with the computer program.
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BASEGHI, BEHDAD. "THREE-DIMENSIONAL SEEPAGE THROUGH POROUS MEDIA WITH THE RESIDUAL FLOW PROCEDURE." Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/184107.
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The purpose of this study is to present the development and application of residual flow procedure for analysis of three-dimensional (3-D) steady-state and transient seepage. The finite element equations are derived using a pseudo-variational principle which leads to a transient residual flow (load) vector that, in turn, is used to correct the position of the free surface iteratively. The procedure involves a fixed mesh which requires no mesh regeneration during transient analysis and during iterations. The procedure is also capable of handling material nonhomogeneities and anisotropy with relative ease. Several applications are made including verification with respect to closed-form solutions, and with results from a laboratory glass bead model simulating three-dimensional situations. For these glass beads, the coefficients of permeability and specific storage are also evaluated experimentally.
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Smiderle, Camila de Souza Dahm. "Segurança de barragens : análise da instrumentação da barragem de Itaúba." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/115274.
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Neste trabalho foi feita a análise das leituras da instrumentação da barragem de terra e enrocamento de Itaúba, localizada no centro do estado do Rio Grande do Sul, coletada ao longo de 35 anos. A auscultação por instrumentação atual inclui medidores de vazão, piezômetros, marcos de deslocamento superficial e medidor de recalque tipo KM, compondo um banco de dados de 10.000 dados de leitura. Foi observado que as vazões medidas através dos drenos de fundação da barragem reduziram pela metade desde o primeiro ano de operação da barragem até o final de 2013, embora os níveis piezométricos do sistema de drenagem à jusante não tenham sofrido alteração. As vazões dos filtros inclinado e vertical são afetadas pelas chuvas, mesmo assim foi possível concluir que as vazões reduziram 1/3 em comparação com a vazão logo após o segundo enchimento do reservatório. A vazão pela barragem e fundação era de 1.800 l/min no primeiro ano de operação decrescendo para 930 l/min (dez / 2013). Observou-se que até o fim do período construtivo já haviam ocorrido 101,75cm de recalque (92% de todo o recalque medido). Os recalques do núcleo estabilizaram entre o 5° e 10° ano de operação da barragem, isto é, desde 1988 a barragem não apresenta recalques significativos. O recalque total de Itaúba foi de 109,6cm que representa 1,2% da altura da seção onde o medidor de recalque está instalado. A análise permite concluir que a Barragem de Itaúba esta estabilizada quanto aos deslocamentos verticais e horizontais. Apesar de tratarse de dados de leituras coletados desde 1976, as informações apresentadas aqui são de relevante interesse e ainda não haviam sido publicadas.In this work, the analysis of Itauba dam instrumentation is carried out. This earth and rock fill dam is located in the center of Rio Grande do Sul state and the readings cover its 35 years of operation. The currentinstrumentation includes flow meters, piezometers, surface displacement and settlements gauge type KM, composing a 10,000 reading database. It was observed that the flow rates measured through the dam foundation drains reduced to half since the first year of dam operation, although the piezometric levels of the downstream drainage system showed no significant change. Flow rates of inclined and vertical filters are affected by the rains, even so it was still possible to conclude that the flows reduced circa of 1/3 compared to the flow after the second filling of the reservoir. The flow through the dam and foundation which was 1,800 l / min in the first year of operation decreased to 930 l / min (Dec / 2013). It was observed that by the end of the construction period had occurred 101,75cm of settlement (92% of all the measured settlement). The settlement core stabilized between the 5 th and 10th year of dam operation, that is, since 1988 the dam does not present significant settlements. The total discharge of Itaúba was 109,6cm representing 1.2% of the section height where repression meter is installed. The analysis shows that the Itaúba dam has stabilized its vertical and horizontal displacements.
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Banti, Erika Verfasser], and Joachim [Akademischer Betreuer] [Stahlmann. "A methodology for the seismic assessment of existing earth dams in Italy / Erika Banti ; Betreuer: Joachim Stahlmann." Braunschweig : Technische Universität Braunschweig, 2018. http://d-nb.info/1175815179/34.
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Banti, Erika [Verfasser], and Joachim [Akademischer Betreuer] Stahlmann. "A methodology for the seismic assessment of existing earth dams in Italy / Erika Banti ; Betreuer: Joachim Stahlmann." Braunschweig : Technische Universität Braunschweig, 2018. http://d-nb.info/1175815179/34.
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Leme, Rosiel Ferreira. "Evaluation of a methodology for the design of small earth dams in semiarid region: construction, testing and numerical modeling." Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=16595.
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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoA common problem of the Brazilian semiarid regions is water scarcity. An alternative to attenuate this severe regional problem consists in storing water during the rainy season, in dams with small storage volumes, usually built with inefficiently compacted embankments, which can contribute to the collapse during the first filling. The main goal of this work is to evaluate a construction methodology for earth dams in semiarid regions, taking into account the problems of inadequate compaction and water shortages. To achieve this, a study was done on a theoretical and experimental basis, in order to better understand the mechanical behavior of small dams that collapse during the first filling. An experimental dam was built in QuixadÃ-CE, following the proposition of Miranda (1988), which suggests a zoned cross section, built with low water content, with a better compacted core and side slopes with less efficient compaction. The embankment of this experimental dam was instrumented with piezometers (standpipes) and limnimetric rules, to monitor the filling and operation stages. Another developed study in this research refers to the avant-garde evaluation of suction in earth dams, using a device developed by researchers from the Department of Agricultural Engineering, at the Federal University of CearÃ, a capacitive sensor. To obtain the geotechnical parameters for the embankment soil, some laboratory tests were performed, such as characterization tests, compaction, consolidation and permeability tests, as well as shear strength and triaxial compression (saturated and unsaturated) ones, and also tests to determine the soil-water characteristic curve (using the filter paper method). The results were used in a numerical modeling of transient flow, using the software Slide, associated with UNSTRUCT, to predict the stress-strain behavior of the experimental dam. The results pointed to the occurrence of collapse in the soil structure of the slopes, which indeed happened after the first filling, since large longitudinal cracks were found in loco. The dam stability was also evaluated, by reducing the shear strength parameters, noting its stability, and thus proving efficient what Miranda (1988) proposed: a zoned embankment built with reduced costs of earthworks and low water consumption, contributing to the development of a low-cost methodology for the construction of small dams in the Brazilian semiarid.
Uma das problemÃticas do semiÃrido nordestino à a escassez de recursos hÃdricos. Para atenuar este forte problema regional, à comum realizar o armazenamento da Ãgua, durante o inverno, em barramentos com pequeno volume de acumulaÃÃo, construÃdos geralmente com maciÃos ineficientemente compactados, o que pode contribuir para a ruptura da obra durante o enchimento. O objetivo principal deste trabalho à avaliar uma metodologia de construÃÃo de barragens de terra em regiÃes semiÃridas, levando em consideraÃÃo os problemas de compactaÃÃo inadequada e escassez de Ãgua. Para tanto, foi empreendido um estudo, a partir de bases teÃricas e experimentais, a fim de melhor entender o comportamento mecÃnico de pequenas barragens que entram em colapso durante seu primeiro enchimento. Para tanto, foi construÃda uma barragem experimental no MunicÃpio de QuixadÃ-CE, seguindo a proposta de Miranda (1988), que sugere uma seÃÃo-tipo zoneada, construÃda com baixa umidade, tendo o nÃcleo melhor compactado e os espaldares executados com compactaÃÃo menos eficiente. O maciÃo desta barragem experimental foi, entÃo, instrumentado, com piezÃmetros e rÃguas linimÃtricas, para monitorar o enchimento e a operaÃÃo. Outro estudo desenvolvido nesta pesquisa foi o emprego vanguardista, na avaliaÃÃo da sucÃÃo em barragens de terra, de um equipamento desenvolvido por pesquisadores da Engenharia AgrÃcola da Universidade Federal do Cearà (UFC), para a determinaÃÃo da umidade do solo, um sensor capacitivo. Para a obtenÃÃo dos parÃmetros geotÃcnicos do maciÃo, foram realizados ensaios de caracterizaÃÃo, compactaÃÃo, adensamento duplo, permeabilidade e cisalhamento direto e de compressÃo triaxial (saturado e nÃo saturado), alÃm de ensaios para a determinaÃÃo da curva de retenÃÃo do solo (mÃtodo do papel de filtro). Os resultados foram utilizados em uma modelagem numÃrica de fluxo em regime transiente, com o auxÃlio do programa Slide, associados ao UNSTRUCT, para a previsÃo do comportamento tensÃo x deformaÃÃo do solo da barragem experimental. As anÃlises indicaram a ocorrÃncia de colapso da estrutura do solo dos taludes, fenÃmeno observado in loco apÃs o enchimento, jà que a obra apresentou grandes trincas longitudinais em seus taludes. A estabilidade da barragem tambÃm foi avaliada, atravÃs da reduÃÃo dos parÃmetros de resistÃncia ao cisalhamento, constatando sua estabilidade, e comprovando, assim, a eficiÃncia da proposta de Miranda (1988), de um maciÃo zoneado construÃdo com reduÃÃo de custos de terraplenagem e do consumo de Ãgua, contribuindo para o desenvolvimento de uma metodologia de baixo custo para a construÃÃo de pequenas barragens no semiÃrido brasileiro.
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Hoepffner, Roland. "Distributed fiber optic strain sensing in hydraulic cencrete and earth structures : measuring theory and field investigations on dams and landslides /." München : Lehrstuhl und Versuchsanstalt für Wasserbau und Wasserwirtschaft, Technische Universität München, 2008. http://opac.nebis.ch/cgi-bin/showAbstract.pl?u20=9783940476135.
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HENRIQUES, José Lamarck Pereira. "Abordagem sobre a construção, instrumentação e operação das paredes diafragmas do sistema de barragens Gramame / Mamuaba." Universidade Federal de Campina Grande, 1993. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/2138.
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JOSÉ LAMARK PEREIRA HENRIQUES - DISSERTAÇÃO PPGECA 1993..pdf: 33749440 bytes, checksum: e11f849d78d25d2e4af28abaa5c1be6d (MD5)Made available in DSpace on 2018-11-06T20:01:57Z (GMT). No. of bitstreams: 1 JOSÉ LAMARK PEREIRA HENRIQUES - DISSERTAÇÃO PPGECA 1993..pdf: 33749440 bytes, checksum: e11f849d78d25d2e4af28abaa5c1be6d (MD5) Previous issue date: 1993-02-05
Este trabalho apresenta um estudo do comportamento do sistema de barragens de terra Gramame / Mamuaba, construído no município de Alhandra, PB, situado a 20 Km ao sul da capital do Estado da Paraíba, João Pessoa. Ênfase foi dada às pressões da água intersticial na fundação do maciço e as paredes diafragmas inseridas no sistema. 0 estudo teve como objetivo analisar os dados fornecidos pelos instrumentos instalados na obra, limitados pelo período final de construção, primeiro enchimento do reservatório e dois anos iniciais de operação. No capítulo de análise das pressões intersticiais procurou-se mostrar a evolução das mesmas através de seções transversais das barragens. O comportamento do contato núcleo-fundação durante a evolução do enchimento do reservatório foi mostrado através da piezometria traçada em algumas das barragens. Uma abordagem sobre a construção da parede diafragma, instrumentação utilizada na Engenharia Geotécnica e arranjo geral da obra é apresentada, com a finalidade de fornecer uma visão global do estudo efetuado.
This work presents a study on the behaviour of dams constructed in the municipal district of Alhandra, PB, situated twenty kilometers to the south of the capital of Paraiba State, Joao Pessoa. Emphasis was given to the porous water pressures in the foundation of the compact and of the diaphragm walls inserted in the system. The objectiva of the sudy was to anlyse the data provided by the instruments inserted in the construction, 1 imitated by the last phases of the construction, first filling up of the resevoir and two inicial years of operat ion. In the chapter of the analysis of the pressures water filtration it was shown the evolution of it by means of the transverse sections to the dam. The behavior of the nucleus foundation contact during the period of the filling of the resevoir was shown by means of drawning in some sections of the dam. A study of the construction of the diaphragm walls, instruments utilized in the geotecnnical engineering and general arrangement of the work is presented, with the view to providing a global view of tie study.
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Al-Riffai, Mahmoud. "Experimental Study of Breach Mechanics in Overtopped Noncohesive Earthen Embankments." Thesis, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/31505.
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A comprehensive experimental program dealing with three-dimensional overtopping and breach development as well as two-dimensional overtopping physical tests of noncohesive earth embankments has been conducted on scale models in the Hydraulic Laboratory at the Department of Civil Engineering at the University of Ottawa. The experimental program which consisted of three phases focused on geotechnical and hydraulic aspects of the embankment breach mechanism. The first two phases focused on two test series for the three-dimensional breach overtopping tests: drainage and compaction. The test series were designed to determine the embankment breach characteristics using test parameters which have not been adequately identified or controlled in past noncohesive physical models: initial soil-water state and optimum dry unit weight. Both parameters were controlled in laboratory tests by means of compaction effort and seepage through the embankment body, respectively. The dynamic compaction technique employed in the preliminary experimental phase was refined to represent a more realistic method. A novel method was thus designed to simulate the construction of a real-size prototype embankment, where a vibratory and static load was used to apply and control, respectively, the compaction effort. The hydraulic aspects of the embankment breach mechanism were also investigated. For the first time, scale series tests have been used to assess the Froude criterion using tilted and quasi-exact geometric scales under very low inflow within the scope of three-dimensional breach overtopping. Data measurements included a time-history of water surface levels and video footage captured from three locations: upstream, downstream and above the embankment models. The analysis for the spatial breach overtopping tests involved measurement of the breach outflow hydrograph and breach channel evolution at the upstream slope, using hydrologic routing and a developed photogrammetric technique using the video footage, respectively. An expression which estimates the breach outflow based on this apparent upstream control section was therefore derived. The relationship between the measured and estimated breach outflow was expressed in terms of breach discharge efficiency. The third phase of the experimental program was comprised of two-dimensional overtopping tests to investigate the erodibility of a steep slope in overtopped noncohesive embankment models. A novel experimental two-dimensional configuration used to measure the pore-water-pressures within the embankment model body was developed using micro and standard tensiometer-transducer-probe assemblies, designed, assembled and tested at the Geotechnical Engineering Laboratory. A transient flownet analysis was developed using ArcGIS and the time-history of the pore-water-pressure measurements. All flow parameters were computed using the free water surface and bed profiles captured using a photogrammetric technique and the developed hydrologic routing method. Using the one-dimensional Saint-Venant equations, an analytical expression for the bed shear stress was derived to take into account the effects of unsteady flow, boundary seepage and steep slopes. Using the measured erosion rates and the sediment continuity principle, the bed mobility relationship expressed by the Shields and transport parameters was revisited to account for the effects of unsteady and supercritical flow on a downstream steep slope in the presence of boundary seepage. This novel transient flownet approach will lead to the development of new sediment mobility relationships for breach flows, instead of the classical sediment transport-capacity formulations which are based on steady, subcritical and normal flow conditions.
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Çakmak, Olcay Uyanık Osman. "Baraj alanlarındaki problemlerin jeofizik çalışmalarla (sismik-elektrik) belirlenmesi Eşeni HES ve Lamas-III örneği /." Isparta : SDÜ Fen Bilimleri Enstitüsü, 2008. http://tez.sdu.edu.tr/Tezler/TF01226.pdf.
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SOUSA, João Augusto Barbosa. "Sistema computacional para análise de fluxo através das barragens de terra e rock-fill utilizando elementos finitos." Universidade Federal de Campina Grande, 1991. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/2130.
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JOÃO AUGUSTO BARBOSA SOUSA - DISSERTAÇÃO PPGECA 1991..pdf: 20226382 bytes, checksum: eba1c136d21ab9224bc5d71dd5640c90 (MD5)Made available in DSpace on 2018-11-06T00:47:32Z (GMT). No. of bitstreams: 1 JOÃO AUGUSTO BARBOSA SOUSA - DISSERTAÇÃO PPGECA 1991..pdf: 20226382 bytes, checksum: eba1c136d21ab9224bc5d71dd5640c90 (MD5) Previous issue date: 1991-03-06
Este trabalho consiste no desenvolvimento e apresentação de uma sistemática de cálculos que, utilizando elementos finitos e microcomputadores, permite dimensionar e posicionar fenômenos hidráulicos no interior dos sistemas, maciços, fundações e dispositivos de proteção das barragens de terra e rock-fill, quando esses se encontrarem em regime permanente e submetidos a variações de fluxo, nas fases de construção, operação e manutenção. Buscando-se atingir ao objetivo pretendido, elaborou-se um sistema de programas e arquivos que, integrados, possibilita a utilização do Programa FPM500 de modo prático. O FPM500 trata dos escoamentos nos meios porosos, confinados e não confinados, nos sistemas bidimensional e/ou tridimensional com simetria de revolução. Entretanto, apesar de flexível, para o seu emprego, era grande a quantidade de dados de entrada a serem informados, diretamente, pelos usuários e, por ser acoplado a um gerador de malhas, aumentava o número de informações, levando esse, na versão original, a ser processado somente em computadores de grande porte. Na sistemática apresentada, inicia-se com um arquivo contendo informações relativas aos blocos estruturais. Um programa acoplado a um renumerador processa essas e renumera todos os nós da malha de elementos, assim reduzindo as bandas das matrizes de fluxo e otimizando memórias em microcomputadores. Este recurso possibilita substancial ganho em velocidade, em busca das soluções dos sistemas com múltiplas equações lineares simultâneas. Os dados resultantes deste processamento permitem a confecção de malhas integradas por elementos triangulares e/ou quadrilaterais lineares, no sistema bidimensional simultâneas. Os dados resultantes deste processamento permitem a confecção de malhas integradas por elementos triangulares e/ou quadrilaterais lineares, no sistema bidimensional
This dissertation deals with the development and the presentation as well of a systematics of calculus that, by making use of finite elements and microcomputers alike, enables both to settle the dimension and the position of hydraulic phenomena in the interior of systems, massifs, foundations and protection organs for earth and rock-fill dams, when the latter are to be found at everlasting rate and suodued to flood variations in the construction, operation and maintenance phases. In the search for an intended purpose, a program and files system was carried out which, once integrated, makes feasible the utilization of Program FPM500 in a practical way. Such a program (viz., FPM500) is related to flows in porous enviroments, restrained or no restrained, in bidimensional and/or tridimensional systems with revolution symmetry. However, despite being flexible for its usage, the quantity of input data to be directly informed by users is huge and, on account of its being coupled to a network generator, it increased the number of informations so that it, at the long run, finished being processed only mainframe computers. In the presented systematics, one begins with a file encompassing informations related to structural blocks. A program coupled to a renumerator processes them and numbers again ali nodes of the elements network by so reducing the flow matrix bandwidth therefore de creasing storage requirements in the computer. Such resource enabls a substantial gain in speed in the systems with mutiple linear simultaneous equations. The data arising from that processing enable the making of integrated networks by triangular and/or four-sided linear elements in the bidimensional system. In another program, the data necessary to the studies of different hydric systems are completed. Therein the outputs of GETOP Program are resettled, the refomations dealing with the boundary conditions and with structural blocks. Such data are kept in files, appropriately shaped in a given format in order to feed Program FPM500. Program FPM500 processes ali elaborated informations as it calculates loads, pressures and flows by providing a report with informations likely to interest studies of hydraulic stability of earth and rock-fill dams. The presented methodology has the advantage to exclude the great amount of blunders committed on input data, in the usage of finite elements thrregh conventional processes. There is also the possibility of a future implementation of graphic programs for drawing element networks thrugh plotter or video. Thus, one is afforded to state that such a systematic, beyond facilitating the calculi, presents confidence and speed as it can be used in different practical equations, the aim of which is likely to be the previous knowledge of the conditions of hydraulic stability in those structures.
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Guo, Jinxing [Verfasser], Peter-Wolfgang [Akademischer Betreuer] Graeber, Rudolf [Akademischer Betreuer] Liedl, Peter [Akademischer Betreuer] Werner, and Makoto [Akademischer Betreuer] Nishigaki. "Stability Analysis of Earth Dams and Dikes under the Influence of Precipitation and Vegetation / Jinxing Guo. Betreuer: Peter-Wolfgang Graeber ; Rudolf Liedl ; Peter Werner. Gutachter: Peter-Wolfgang Graeber ; Rudolf Liedl ; Makoto Nishigaki." Dresden : Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://d-nb.info/1093412380/34.
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Jalilov, Shokhrukh-Mirzo. "Impact of Rogun Dam on Downstream Uzbekistan Agriculture." Thesis, North Dakota State University, 2011. http://hdl.handle.net/10365/16332.
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Strains among the states of Central Asia caused by overuse of the region?s scarce water resources have been increasing in recent years. This is especially true for the relations between Tajikistan, upstream, and Uzbekistan, downstream, on the Amudarya River. Major controversy exists over constructing Rogun Dam on the Vakhsh River, a tributary of the Amudarya River. Construction of Rogun Dam, with a planned height of 335 m (1099 ft), began in 1976 but was stopped in 1991 with the breakup of the former Soviet Union. The intent of this dam is to supply Tajikistan with energy, but a side effect will be the changed flow regime of the Amudarya River to downstream states (especially Uzbekistan). The major impact will be on the agricultural sector of Uzbekistan. The objectives of this study are to estimate the monetary impacts of Rogun Dam and propose mitigation measures to minimize impacts. The study investigates the nature and extent of those impacts and indicates policy implications to mitigate negative consequences of the possible water shortage in summer by assessing the baseline situation and comparing that situation with future status-quo (no changes) level of water. Future water shortage could cost Uzbekistan annually over US $609 million economic loss in agriculture, reduce the country?s GDP by 2.2%, and result in 336,000 unemployed people. If Uzbekistan changes its present water use practice and increases water use efficiency, the future water shortage during irrigation periods will not as seriously affect the country?s economy, as adaptive management measures could cut the losses by 40%.
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Charatpangoon, Bhuddarak. "SEISMIC SAFETY EVALUATION OF EARTH DAM AND POSSIBLE REHABILITATION METHODS." 京都大学 (Kyoto University), 2014. http://hdl.handle.net/2433/192169.
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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.
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Ce memoire est consacre a l'analyse de l'influence des parametres hydrauliques et mecaniques sur la diffusion de la surpression interstitielle dans le corps d'un barrage en remblai lors de la variation du niveau d'eau du reservoir. Il approfondit plus particulierement la determination de la stabilite du barrage en terre au cours de la vidange rapide, qui est le point delicat et le plus meconnu dans comportement des barrages en remblai. Differents codes de calcul ont ete utilises et testes : gefdyn, ns2d, talren et flac. Les analyses de leurs resultats ont ete effectuees pour evaluer la stabilite et comparer aux approches traditionnelles. Avec une configuration hydraulique pure, des calculs ont permis d'etudier l'influence de la permeabilite du sol, de la compressibilite de l'eau et de la desaturation sur la diffusion de la pression au cours des phases de remplissage et de vidange de la retenue. A partir d'une configuration couplee hydraulique-mecanique et dans le cadre de l'elasticite, d'autres calculs ont permis de mettre en evidence l'influence du module de compressibilite du sol sur l'evolution de la pression interstitielle dans l'ouvrage. La variation de la pression interstitielle est egalement fonction du comportement non-lineaire des materiaux constituant l'ouvrage, et notamment de la forme la surface de charge, comme montre la comparaison des lois de comportement mohr-coulomb et hujeux. Les calculs non-lineaires couples sont effectues, interpretes avec differents criteres de rupture et compares aux approches classiques pour l'estimation de la stabilite du parement amont pendant la vidange rapide d'un barrage avec quatre materiaux argileux compactes, utilisant deux lois de comportement de mohr-coulomb et de hujeux. La comparaison de ces resultats est exploitee utile pour mieux connaitre les limites de chacune des methodes.
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Farkouh, Bassam. "Le filtre géosynthétique dans les ouvrages de drainage : essais de laboratoire et observations in situ." Université Joseph Fourier (Grenoble), 1994. http://www.theses.fr/1994GRE10204.
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L'emploi des geotextiles comme filtre se generalise dans les systemes de drainage en geotechnique en raison de leurs caracteristiques hydrauliques tres performantes. Mais les geotextiles doivent les conserver a long terme, memes dans des conditions critiques de filtration. La filtration de sols coherents fissures avec un filtre geotextile presente, a priori, des conditions critiques de filtration a cause du risque de mise en suspension des particules, entrainees par l'ecoulement, qui risquent de colmater le filtre. Ce probleme a ete traite par plusieurs approches: ? une etude locale a l'echelle de l'interface sol-geotextile avec un essai de filtration de sol en suspension realise en laboratoire ? une etude globale: ont ete reproduites au laboratoire les conditions de filtration d'un geotextile utilise en enrobage de drain agricole. Deux cuves de grandes dimensions ont ete realisees, l'une avec un massif homogene (temoin), l'autre avec un massif fissure artificiellement ou le risque d'avoir du sol en suspension est eleve. ? une etude in situ du comportement de tranchees drainantes equipees d'un filtre geotextile. Ces tranchees sont realisees dans les argiles litees ou, la aussi le risque d'avoir des ecoulements charges des particules en suspension est important. Par ailleurs: le comportement de filtres geotextiles utilises pour la premiere fois dans un barrage en terre (barrage de valcros), a ete etudie apres une vingtaine d'annees de fonctionnement. Enfin, cette etude a ete completee par des calculs d'ecoulement (elements finis) pour montrer l'influence d'un eventuel colmatage sur le fonctionnement de l'ouvrage
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Michalčíková, Magdaléna. "Vývoj injektážních směsí pro dodatečné těsnění sypaných hrází." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227206.
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Seal of sand or gravel by chemical injection is known and used for a long time. Chemical grouting are however expensive and sometimes the use of cement does not lead to desire effects. So it is trying to find new materials and methodologies injection arrangement works. To achieve savings of chemical products are added to a mixture clay and cement. Clay-cement grouting mix are used not only in order that they are better quality, but also because in this way proposed mixtures have a tendency to penetrate better into incoherent sediments that need additional sealant of chemical injection. For further possible reductions of economic terms the mixture is trying to replace the classic clay. As a suitable substitute for classic clay is to a certain extent the use of secondary raw materials. Above all it is fly ash. As a part of my thesis I deal with the appropriateness use of these materials and examining their properties in the mixture. It was found that by using fly ash were improving consistency of the fresh mixture, reducing the amount of water-cement ratio and reduce shrinkage of the mixture. On the other hand, by using fly ash has been increasing decantation, permeability atc. In the next stage of my work was examined the influence of the quality of cement, lime and liquefaction in the mixture. The aim of thesis is to propose the optimal injection mixture for additional sealing earth dams.
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Guo, Xiangfeng. "Probabilistic stability analysis of an earth dam using field data." Thesis, Université Grenoble Alpes, 2020. http://www.theses.fr/2020GRALI017.
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Compte tenu de la nature des sols, des incertitudes sur leurs propriétés sont largement rencontrées en géotechnique, en particulier dans le domaine des barrages en terre. Actuellement, il est de plus en plus nécessaire de tenir compte de ces incertitudes pour l'évaluation de la sécurité des grands barrages, notamment dans le cadre des études d’analyse de risques. Cependant, les analyses probabilistes sont complexes et difficiles à mettre en œuvre en raison du nombre limité de mesures, des temps de calcul importants et des limites des méthodes fiabilistes implémentées dans les outils de simulation commerciaux. De plus, la plupart des études précédentes sont basées sur des cas académiques et des données hypothétiques.Ce travail tente de résoudre les problèmes mentionnés ci-dessus en fournissant une étude d'analyse probabiliste pour la stabilité d'un barrage réel en terre en considérant les données in-situ disponibles. Cette étude inclut les éléments principaux suivants: (1) définition de la variabilité des sols en utilisant les mesures disponibles; (2) développement des modèles déterministes; (3-4) analyses probabilistes bu barrage en utilisant des approches en variables aléatoires et en champs aléatoires; (5) analyse 3D de la fiabilité du barrage considéré. Des méthodes fiabilistes avancées (par exemple le métamodèle adaptatif) sont introduites. Cela permet d'estimer précisément la probabilité de rupture du barrage et les valeurs statistiques des facteurs de sécurité avec un temps de calcul significativement réduit. En outre, certaines questions, qui restaient floues dans le domaine de l'analyse probabiliste des barrages, sont discutées (e.g. l’analyse de sensibilité globale des paramètres hydrauliques et géo-mécaniques des sols ; l’étude des performances de cinq méthodes de fiabilité; la simulation/comparaison de trois types de champs aléatoires : générique, conditionnel et non-stationnaire). Le travail présenté, basé sur des données réelles, pourrait être un bon complément aux études probabilistes existantes des ouvrages géotechniques. Les lecteurs pourront également trouver des informations utiles à partir des résultats obtenus afin de mieux résoudre les problèmes pratiques de géo-ingénierie dans un cadre probabilisteUncertainties 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
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Goch, Stefan. "Das Ruhrgebiet : die Entstehung einer Region?" Universität Potsdam, 2001. http://opus.kobv.de/ubp/volltexte/2008/2415/.
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Inhalt:
Konstruktion einer Region
Kommunalverband Ruhrgebiet
Region ohne Organisation
Begriffliche Wahrnehmung der Region
Entwicklung einer regionalen politischen Kultur im strukturellen Wandel
Regionales Bewußtsein, Image, Selbstvergewisserung
Schluß
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Esser, Hartmut. "Ist das Konzept der Assimilation überholt?" Universität Potsdam, 2003. http://opus.kobv.de/ubp/volltexte/2009/3063/.
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Inhalt:
1 Die Assimilation und ihre Alternativen
2 Die Situationslogik der Assimilation
3 Die „Interaktion“ von ethnischer Segmentation und ethnischer Ungleichheit: Das Beispiel der ethnischen Mobilitätsfalle.
4 Perspektiven
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RODRIGUES, RODRIGO DE LIMA. "BEHAVIOR OF THE LEFT EARTH DAM OF ITAIPU IN OPERATION PERIOD." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2017. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=32942@1.
Full textAbstract:
PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
PROGRAMA DE EXCELENCIA ACADEMICA
Itaipu Binacional é uma usina hidrelétrica localizada no Rio Paraná, entre Brasil e Paraguai. A barragem que forma o reservatório é composta por estruturas de concreto, enrocamento e terra. Após o enchimento do reservatório, em 1984, o nível do lago se manteve com variação média de 1,5 m, entre as cotas 219 m e 220,5 m, cotas de operação da usina, apenas em poucas ocasiões foi reduzido abaixo da cota 219 m. Entre os anos de 2012 e 2015, devido à crise hídrica no sudeste do país, Itaipu passou a operar de maneira atípica a fim de suprir a queda na produção energética de outras usinas, isso fez com que a variação do nível do reservatório aumentasse para 4 m e permanecesse mais tempo em cotas abaixo do nível normal. Nesse mesmo período a instrumentação apontou um recalque de aproximadamente 5 cm em um trecho da Barragem de Terra da Margem Esquerda (BTME). Esse recalque está abaixo dos limites previstos, porém foi considerado atípico já que, desde a construção, os recalques medidos variam de 1 a 2 cm. Neste trabalho foram realizadas simulações para análises de fluxo, estabilidade e recalques no referido trecho, considerando a variação do nível do reservatório no período atípico. As análises permitiram observar o comportamento das poropressões no maciço compactado e fundação, determinar os fatores de segurança críticos para o período nos taludes de montante e jusante e em que momento eles acontecem. As simulações também mostraram que o recalque detectado pela instrumentação não é atribuído ao adensamento primário devido à variação do nível do reservatório.
Itaipu Binacional is a hydroelectric plant located on the Parana River,between Brazil and Paraguay. The dam that forms the reservoir is made up of concrete, rock and earth-filled structures. After the reservoir was filled in 1984, the level of the lake remained with an average variation of 1,5 m, between 219 m and 220,5 m (the operating elevation of the plant). The reduction below elevation 219 m only happened in very few occasions. Between the years of 2012 and 2015, due to the water crisis in the southeast of the country, Itaipu began to operate in an unprecedented manner, in order to compensate for the decrease in other energy production plants. Such operation not only caused the reservoir variation level to increase to 4 m, but also made the water level remain below the average readings. In the same period, the instrumentation indicated, in a specific region, a 5 cm settlement of the Left Earth Dam. This fact was considered atypical, because, since the construction, the measured recharges had varied 1 or 2 cm at most. In this work, flow, stability and recharge simulations were performed to analyze the abovementioned region considering the variation of the reservoir level in this uncharacteristic period. With these analyzes it was possible to observe how the porepressures behave in the dam and foundation; what the critical safety factors for the period in the upstream and downstream slopes are; and when they occur. The simulations also showed that the settlement detected by the instrumentation isn t attributed to consolidation due to the variation of the reservoir level.
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BARRANTES, PERLITA ROSMERY ESAINE. "SEISMIC AND HYDROMECHANICAL ANALYSIS OF A ZONED EARTH DAM IN PERU." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2013. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=34814@1.
Full textAbstract:
PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
PROGRAMA DE EXCELENCIA ACADEMICA
Prever o comportamento de estruturas de solo de grande porte, como barragens, durante a construção, em operação e inclusive sob o efeito de eventos sísmicos tem muita importância para evitar possíveis consequências catastróficas e indesejáveis. Neste sentido, este estudo apresenta, através de uma análise acoplada hidromecânica pelo método dos elementos finitos, os resultados numéricos discutidos em termos de tensões e suas trajetórias, deslocamentos verticais e horizontais, poropressões, incluindo a estabilidade de taludes. Além disso, é apresentada também a análise da resposta sísmica quando a estrutura é submetida a um carregamento dinâmico. Para tanto, analisou-se a barragem de terra zonada Recreta, situada na província de Huaraz - Peru, mediante o emprego do programa PLAXIS 2010. Foram descritas as metodologias de análise para simular passo a passo a construção incremental da barragem, o primeiro enchimento do reservatório por incrementos de níveis de água, o avanço da frente de saturação até atingir a condição de fluxo permanente e a avaliação da resposta dinâmica quando a barragem é submetida ao último maior movimento sísmico (história de acelerações) registrado em 1974 na capital do Peru, Lima, adjacente à cidade onde se localiza este projeto. Também se empregou o software Seismosignal versão 5.0, para o tratamento do sinal sísmico, e os programas Shake 2000 e Strata para a calibração dos parâmetros de amortecimento. Os resultados fornecidos por estas ferramentas numéricas foram avaliados em função do fundamento teórico, exposto na revisão bibliográfica, e de uma série de testes para o estabelecimento das metodologias e procedimentos mais adequados para a obtenção destes resultados.
Predicting the behavior of soil structures, such as large-scale dams, during construction and operation, including the effect of earthquakes, is very important to prevent possible catastrophic and undesirable consequences. This study presents, through a coupled hydromechanical analysis by the finite element method, numerical results discussed in terms of stresses and trajectories, vertical and horizontal displacements, poropresssures and soil slope stability analyses. The investigation of the seismic response when the structure is subjected to a seismic load is also included, considering the dynamic behavior of the zoned earth dam Recreta, located in the province of Huaraz in Peru. The numerical analyses were carried out using the computational program PLAXIS 2010 to simulate the incremental construction of the dam, the first fill of the reservoir by increments of the water levels, the advance of the front of saturation until achieving the condition of steady flow condition and the seismic response when the dam is subject to the last major earthquake (accelerations history) registered in Peru s capital, Lima, in 1974, which is located near to the site of the Recreta dam. The Seismosignal software version 5.0 was also used for seismic signal processing and the programs SHAKE 2000 and STRATA were also employed for calibration of the damping parameters of the soils. All the results provided herein were discussed, based on the theoretical basics presented in the literature review as well as on the various numerical examples investigated with the main purpose to better understand the hydromechanical behavior of a zoned earth dam subject to static and dynamic loads.
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Davoudi, 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.
Full textAbstract:
In zoned dams, it is expected that pore pressure is uniformly dissipated from the upstream to the downstream side of the core. Based on this hypothesis, the potential profile across the core in a steady state seepage flow is expected to be more or less linear and the equipotential lines should be distributed quasi-uniformly. This analysis is based on a homogeneous saturated permeability throughout the core. For some large cores made of glacial moraine (till), it has been reported that the pore pressures were significantly in excess of expected values during and after reservoir filling. The materials used in the cores are well graded silty sand soils including a small percentage of colloidal particles and cobble. This investigation is aimed at understanding this problem, its evolution with time and the influencing factors. The research study includes a series of experimental tests and numerical simulations. Deformations of till material after construction and during impoundment were studied. The mechanism of water infiltration and the evolution of water pressure through the unsaturated till were investigated. The influences of the initial degree of saturation, the volume of water circulating, the effective stress and the back pressure on the degree of saturation and hydraulic conductivity were investigated. An attempt was also made to study the influence of compaction water content on the hydraulic and mechanical behavior of till. Numerical modeling of the LG-4 dam was carried out to illustrate the influence of the degree of saturation on the pore pressure dissipation and flow discharge. The results show that pore pressures in excess in cores made of till are due to heterogeneity in the degree of saturation, and hence in the hydraulic conductivity (coefficient of permeability) across the core. By impounding, reservoir water pressure creates a relatively high hydraulic conductivity zone in the upstream and central portions of the core, resulting in a high hydraulic gradient in the downstream side. After a certain time, the phenomenon of progressive saturation causes the coefficient of permeability to increase in the downstream side, which results in the reduction of the heterogeneity. As a consequence, pore pressures decrease toward theoretical expected values.
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Xu, Yong-Qiang. "Applications of Richards equation to earth dam design and runoff problems." Kyoto University, 2005. http://hdl.handle.net/2433/145028.
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Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第11627号
農博第1483号
新制||農||907(附属図書館)
学位論文||H17||N4020(農学部図書室)
23270
UT51-2005-D376
京都大学大学院農学研究科地域環境科学専攻
(主査)教授 河地 利彦, 教授 青山 咸康, 教授 三野 徹
学位規則第4条第1項該当
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DJILALI, 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.
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Ce memoire presente une etude numerique et cinematique de la stabilite des barrages et des ouvrages en terre. Nous exposons tout d'abord une synthese de formulations des cfficients de securite etablis par les principales methodes anterieures. Nous elaborons ensuite une nouvelle approche de l'analyse de la stabilite des ouvrages en terre pour une forme de rupture circulaire. L'evaluation du cfficient de securite par cette approche ne tient pas compte, comme dans la theorie classique, de scenarios de rupture fictifs (reduction generale de la resistance mecanique du massif du sol), mais de la proximite du champ de vitesse de deplacement calcule par elements finis par rapport au champ de vitesse de deplacement de solide rigide. Cette methode peut se greffer sur un calcul par elements finis et evite la dichotomie entre les calculs en deplacement et les calculs a la rupture. La validation de cette approche se fait tout d'abord en examinant l'influence de la variation de plusieurs parametres (pente, caracteristiques mecaniques et chargement) sur le cfficient de securite cinematique. Les resultats obtenus sont ensuite compares a ceux fournis par les methodes anterieures (classiques et recentes). Nous developpons aussi une extension de l'approche cinematique de la stabilite des ouvrages en terre aux cas de lignes de glissement plus complexes. Les resultats obtenus sont confrontes d'une part a ceux fournis par la procedure cinematique dans le cas d'un glissement circulaire et d'autre part a ceux obtenus par une methode utilisant un scenario d'equilibre limite.
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Zidulka, Amy Diane. "Playing house, home as the necessary context of Margaret Laurence's Dance on the earth." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ48592.pdf.
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Krüger, Fred. "Lohnert, Beate, Vom Hüttendorf zur Eigenheimsiedlung. Selbsthilfe im städtischen Wohnungsbau : ist Kapstadt das Modell für das Neue Südafrika? / [rezensiert von] Fred Krüger." Universität Potsdam, 2004. http://opus.kobv.de/ubp/volltexte/2009/3082/.
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Rezensiertes Werk:
Lohnert, Beate: Vom Hüttendorf zur Eigenheimsiedlung : Selbsthilfe im städtischen Wohnungsbau ; ist Kapstadt das Modell für das neue Südafrika? / Beate Lohnert. - Osnabrück : Univ.-Verl. Rasch, 2002. - 303 S. : Ill., graph. Darst., Kt. - (Osnabrücker Studien zur Geographie ; Bd. 24)
Zugl.: Osnabrück, Univ., Habil.-Schr., 2001
ISBN 3-935326-79-3
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Leser, Hartmut. "Das „DIERCKE Wörterbuch Allgemeine Geographie“ : Idee, Konzept und Perspektiven." Universität Potsdam, 2006. http://opus.kobv.de/ubp/volltexte/2009/3137/.
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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.
Full textAbstract:
La géométrie et la flexibilité d'un canyon sont les paramètres qui affectent grandement la valeur des périodes naturelles dans les barrages en terre. Le canyon entourant des barrages peut être considéré comme un domaine illimité. Pour prendre en compte ces deux effets, le canyon a été modélisé par SBFEM et le barrage en terre, à géométrie limitée, par FEM. La technique hybride SBFEM-FEM pour l'analyse tridimensionnelle dynamique de l'interaction sol-barrage a été validée avec les résultats disponibles dans la littérature. Comme la matrice de rigidité dynamique du domaine non borné est complexe et dépendante de la fréquence, la méthode classique de superposition de modes n'est pas simple pour le système d'interaction sol-structure. Ainsi, pour obtenir la fréquence propre fondamentale, le barrage a été excité en direction amont-aval. Les périodes naturelles du barrage de terre pour des canyons de formes géométriques et de coefficient de impédance différents ont été obtenues. Ils se sont avérés avoir des effets significatifs sur la période naturelle. Les résultats ont été comparés aux données enregistrées réelles. Il a été constaté que les graphiques proposés dans cette étude peuvent être utilisés par des concepteurs de barrages pour l'estimation des périodes naturelles des barrages en terre dans des canyons de formes et de propriétés matérielles différentes. Plusieurs fonctions d'amplification correspondant à différentes conditions de canyon ont été obtenues en appliquant un déplacement uniforme à la limite du canyon. Une étude approfondie a été réalisée pour examiner les effets de la géométrie et de la flexibilité du canyon sur la réponse en régime permanent du barrage. Ces deux effets ont influencé de manière importante les fonctions d'amplification. Alors que la flexibilité du canyon affecte de manière significative la valeur de la fonction d'amplification maximale, cette valeur ne change pas pour les barrages en terre dans lesquels les canyons ont des formes différentes et la même longueur. De plus, la réponse latérale du barrage de terre dans le domaine temporel a été calculée pour analyser les effets susmentionnés lors d'un tremblement de terre réel. Les fonctions d'amplification proposées ont été utilisées pour comparer les spectres de réponse enregistrés du barrage d'El Infiernillo lors des tremblements de terre de 1966 avec la fonction d'amplification calculée. Un accord raisonnable a été observé entre eux. La méthode linéaire équivalente (EQL) a été implémentée dans le FEM. La technique FEMSBFEM a été étendue pour prendre en compte l'effet du comportement non linéaire des barrages en terre. Il a été observé que le comportement non linéaire affecte grandement la fréquence naturelle, la fonction d'amplification et l'accélération de crête maximale du barrage de terre situé dans les canyons. Les effets de la géométrie et de la flexibilité du canyon sur le comportement non linéaire ont été examinés, et on a vu qu'en augmentant la flexibilité du canyon, l'effet de la non-linéarité était diminué. Le barrage d'El Infiernillo a été modélisé par FEM-SBFEM non linéaire 3D, et une comparaison de la fonction d'amplification de crête obtenue par la méthode proposée avec les données enregistrées montre la précision du FEM-SBFEM non linéaire.The 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.
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Meusburger, Peter. "Das „Lexikon der Geographie“ : Konzept, Ziele und Grenzen eines Fachlexikons." Universität Potsdam, 2006. http://opus.kobv.de/ubp/volltexte/2009/3138/.
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Inhalt:
1 Wie kam die Idee eines neuen Lexikons der Geographie zustande?
2 Was sind die Ziele des Lexikons der Geographie und welche Konzeption liegt ihm zugrunde?
3 Welche guten und schlechten Erfahrungen wurden bei der Erstellung des Lexikons gemacht?
4 Inwieweit wurden die Ziele erreicht?