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1
Shaheed, Salma 1966. "Analysis of unsteady flow through an earthen dam using the boundary element method." Thesis, The University of Arizona, 1992. http://hdl.handle.net/10150/278155.
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Unsteady flow through an earthen dam has been investigated using the Boundary Element Method in which the upstream reservoir level may vary in a cyclic manner. The seepage surface at the upstream face is included in the computer model when the water level drops in the upstream reservoir. The use of this model has been illustrated by studying the variation of the phreatic surface in a beach along the Colorado river in the Grand Canyon. The potentials at various internal points are also calculated and compared with those measured in the field. Very good agreement is obtained between the results using the Boundary Element Method and field data.
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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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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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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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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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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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Ikard, Scott. "Geoelectric monitoring of seepage in porous media with engineering applications to earthen dams." Thesis, Colorado School of Mines, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3602502.
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A monitoring methodology is developed for investigating seepage and internal erosion in earthen dams with time-lapse measurements of self-potential anomalies associated with conservative salt and non-conservative heat tracer migration in the subsurface. The method allows for 1) detecting seepage zones in earthen dams and determining the preferential flow paths through seepage zones in a non-invasive manner from the ground surface, 2) monitoring the transient evolution of seepage path geometry, flow velocity, and permeability in real-time if high frequency measurements can be made, and 3) long-term non-invasive monitoring with wired or wireless sensors The method is first theoretically developed and tested in a laboratory using a conservative tracer, and then demonstrated at a 12 m high, 100 m long leaking earthen dam with complex, unknown seepage paths. The method is shown to be capable of rapidly detecting seepage zones discovered during a reconnaissance survey, and delineates the predominant seepage directions through the dam from the time-lapse self-potential anomalies. The time-lapse monitoring approach ensures improved spatial resolution, increased measurement frequencies, and improved data analysis capabilities relative to traditional approaches to seepage detection, and a cost-reduction for the application of this methodology is anticipated to follow advancements in wireless sensing and monitoring technologies. This method is designed to be a more cost-effective means of interrogating earthen dams and levees to answer questions such as: Is the dam safe? What are the geometries of the seepage zones inside of the dam, and over what spatial scale does anomalous seepage occur? What are preferential paths through the seepage zones? Is internal erosion actively occurring? At what rates are the geometries, permeabilities and flow rates of preferential seepage paths evolving?
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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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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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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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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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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.
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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.
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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.
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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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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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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.
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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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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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Araujo, Franklim Rabelo de. "Risco geotÃcnico: uma abordagem estocÃstica para anÃlise da estabilidade de taludes da Barragem Olho dâÃgua no Estado do CearÃ." Universidade Federal do CearÃ, 2013. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=11420.
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nÃo hÃA evoluÃÃo das anÃlises de estabilidade de taludes na Engenharia GeotÃcnica segue de perto o desenvolvimento da MecÃnica dos Solos. Escorregamentos de taludes sÃo uma das formas mais frequentes de movimento de massa. No caso de barragens de terra, trÃs dificuldades sÃo encontradas quando se analisa a estabilidade de taludes: a) a variabilidade dos parÃmetros de resistÃncia do solo; b) dificuldades de se prever as condiÃÃes de fluxo de Ãgua e as pressÃes piezomÃtricas resultantes, e c) dificuldade de antecipaÃÃo das formas mais provÃveis de ruptura, as superfÃcies potenciais a elas associadas e os mecanismos de ruptura envolvidos. Essas dificuldades refletem diretamente no nÃmero de falhas em barragens de terra, que responde por 66% dos acidentes em barragens em todo o mundo. Dados da AgÃncia Nacional de Ãguas apontam que entre 2002 e 2010 foram registrados 800 incidentes com barragens. Como acidentes de grandes proporÃÃes, cita-se a ruptura da barragem de rejeitos de Cataguazes (MG), em marÃo de 2003, que deixou milhÃes de pessoas por semanas sem abastecimento, em razÃo do lanÃamento de soda cÃustica no rio ParaÃba do Sul, bem como o rompimento da barragem de AlgodÃes, em maio de 2009, no PiauÃ. Dessa forma, em razÃo das inÃmeras incertezas nos projetos das barragens, à necessÃria a utilizaÃÃo de metodologia que leve em consideraÃÃo a variabilidade dos componentes envolvidos nas anÃlises de estabilidade de taludes, uma vez que essas incertezas nÃo sÃo consideradas nos mÃtodos determinÃsticos. A anÃlise probabilÃstica de estabilidade de taludes, utilizando o mÃtodo de Monte Carlo, torna-se uma importante ferramenta durante a construÃÃo, enchimento e operaÃÃo de barragens de terra. PropÃe este trabalho uma metodologia simplificada para estimar os parÃmetros hidrÃulicos do solo mediante a retroanÃlise das condiÃÃes de fluxo, comparando as cargas piezomÃtricas medidas no maciÃo, com as calculadas por um programa de computaÃÃo comercial, para, em seguida, estimar a probabilidade de falha nos taludes da barragem de terra. A probabilidade de falha do talude de jusante, anÃlise na condiÃÃo de cheia mÃxima e anÃlise de estabilidade do talude de montante na condiÃÃo de rebaixamento rÃpido, foram realizadas para o caso da barragem Olho dâÃgua, no Estado do CearÃ.
The evolution of slope stability analysis in geotechnical engineering has followed closely the development of soil mechanics . Slope landslides are one of the most frequent forms of mass movement . In the case of earth dams, three difficulties are encountered when analyzing the slope stability: a) the variability of soil strength parameters, b) difficulty of predicting the conditions of water flow and resulting piezometric pressures, and c) difficulty in predicting the most probable forms of rupture, the potential surfaces associated to them, and the rupture mechanisms involved . These difficulties reflect directly on the number of failures recorded with dams, which accounts for 66 % of accidents in dams around the world. Data from the National Water Agency of Brazil show that between 2002 and 2010, 800 incidents were recorded dams. As major accidents, the rupture of tailings in Cataguazes dam in the state of Minas Gerais in March 2003, which left millions of people without water for weeks , due to leakage of caustic soda in the ParaÃba do Sul river , as well as the failure in the AlgodÃo Dam, in May 2009, in Piauà state in northeastern Brazil may be mentioned . Thus, because of the many uncertainties in the projects of dams, the use of a methodology that takes into account the variability of the components involved in the analysis of slope stability of dams is necessary, since these uncertainties are not considered in deterministic methods. The probabilistic analysis of slope stability using the Monte Carlo method, turns out to be an important evaluating tool during construction, filling and operation of earth dams. This work proposes a simplified methodology for estimating soil hydraulic parameters, by means of back-analysis of seepage conditions, comparing the pressure heads measured by standpipe piezometer in the dam, together with those calculated by commercial computing program to, then, estimate the dam slopes probability of failures. The reliability analysis of the downstream slope of the dam in the high level of water condition was done, such as the backslope stability analysis during rapid drawdown of the Olho dâÃgua dam in the State of CearÃ, Brazil.
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Rajaonarivony, Jean De Dieu. "On the way to the new earth an examination of Seventh-Day Adventist eschatology /." Theological Research Exchange Network (TREN), 1986. http://www.tren.com.
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Grant, Jonathan. "Heaven bound, earthly good: an historical analysis of race relations in the Seventh-Day Adventist Church." DigitalCommons@Robert W. Woodruff Library, Atlanta University Center, 2010. http://digitalcommons.auctr.edu/dissertations/174.
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The Seventh-day Adventist Church is a denomination that has contributed much to the development of American society. Although the Church is a religious and social institution, its views on race in America have changed over the years, from its abolitionist approach during the mid 19th century to its stance of non-involvement during the Civil Rights Movement. By studying the race relations in the Adventist Church, this thesis reveals the factors that may have caused its position of non-intervention during the Civil Rights Movement. The thesis analyzes the development of black/white race relations in the Seventh-day Adventist Church, and how it has led to the Church’s stance regarding race during the Civil Rights Movement. The functionalist theory is utilized to elucidate the Church’s racial approach from a sociological perspective. This thesis allows for future research of other religious organizations and how those institutions have helped advance or delay the quest for social freedom amongst African Americans.
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Watkins, Andrew. "Earth Rotation and Deformation Signals Caused by Deep Earth Processes." Bowling Green State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1510767104519046.
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Sweeney, Brian P. "Converged stepped spillway models in OpenFOAM." Kansas State University, 2014. http://hdl.handle.net/2097/17611.
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Master of ScienceDepartment of Computing and Information Sciences
Mitchell L. Neilsen
The United States Department of Agriculture (USDA) is currently researching the effectiveness of various earth dam designs and their ability to prevent erosion. This report utilizes experimental results from the USDA experimental hydraulic engineering research unit to develop computational fluid dynamics models using OpenFOAM. Several variations of smooth and stepped dam models are created and analyzed with OpenFOAM on multiple cores using Message Passing Interface. In this report, seven dam designs are analyzed to extract flow velocities and pressures and animations. This data and OpenFOAM models are helpful for determining potential erosion conditions.
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Damman, Jessica. "Remembering Earth Day: The Struggle over Public Memory in Virtual Spaces." University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1307320285.
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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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Piboon, Monchaya 1976. "Analysis of periodic behavior of GPS time series at Pacoima Dam, California." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/55067.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2002.Includes bibliographical references (leaves 67-68).
High precision GPS receiver can yield position measurements within millimeter level accuracy. This accuracy provides an opportunity to observe subtle changes such as crustal movements. In addition,it allows the monitoring of large structures such as dams for safety reason. A GPS system was installed at Pacoima Dam in order to monitor potential instability. The GPS system consists of 2 receivers, DAMI and DAM2, which are part of GPS network in Southern California. The displacement derived from the GPS receivers indicated that the dam's arch moves periodically with an annual period. Because of the annual period of the time series, we investigated if the movement of the dam arch could be due to thermoelastic deformation. An estimation of the dam arch displacement change based on thermoelastic deformation theory is derived. To analyze the observables, we performed spectral analysis between the GPS displacements and the temperature variation. The spectral analysis results is in agreement with the magnitude derived from thermoelasticity theory. The results show that Pacoima Dam's displacement is consistent with thermoelastic deformation. The water loading however may also have contribution to the movement of the dam.
by Monchaya Piboon.
S.M.
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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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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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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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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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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?
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Schulz, Karsten. "Die Bedeutung räumlicher Strukturen und Muster für das hydrologische Prozessgeschehen." Universität Potsdam, 2006. http://www.uni-potsdam.de/imaf/events/ge_work0602.html.
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Der Referent ist stellvertretender Leiter des Departments Angewandte Landschaftsökologie des UFZ - Umweltforschungszentrum Leipzig-Halle am Fachbereich UmweltsystemmodellierungInterdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung
Workshop vom 9. - 10. Februar 20066
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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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Abreu, Jhonny Gregório Vieira. "Aplicação da aprendizagem baseada na resolução de problemas e do Google Earth™ no estudo sismologia." Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/16830.
Full textAbstract:
Mestrado em Ensino de Biologia e GeologiaA sociedade atual sofreu enormes mudanças nos últimos anos e, devido a isso, os desafios impostos à Educação são cada vez maiores. Atualmente os alunos têm um maior acesso a informações e, como tal, é necessário repensar os métodos que são utilizados pelos professores nas aulas, para que os alunos possam aplicar a diversidade de conhecimentos que possuem e se sintam integrados no processo de ensino e de aprendizagem. O presente trabalho investigativo, implementado numa turma de 10.º ano de escolaridade, procurou distanciar-se de práticas tradicionais, recorrendo à Aprendizagem Baseada na Resolução de Problemas (ABRP) e à Georreferenciação no programa Google EarthTM, para o estudo da Sismologia. Desta forma, ao longo das aulas que envolveram a investigação, foi dada a oportunidade aos alunos de construírem os seus próprios conhecimentos, através de um trabalho colaborativo. De forma geral, as finalidades da investigação, consistem em avaliar as competências que os alunos desenvolvem ao longo das aulas e verificar o desempenho dos alunos e do professor, uma vez que, os alunos são os responsáveis pela construção das suas aprendizagens e o professor unicamente se representa como tutor de todo este processo. Para tal, foram utilizadas diversas técnicas e instrumentos de recolha de dados, tais como observação, análise documental e questionários. Através da sua análise, conclui-se que as finalidades definidas foram alcançadas, tendo os alunos conseguido aperfeiçoar principalmente competências como tomadas de decisão, poder de síntese, autonomia, capacidade de recolha e análise de informações, interajuda, trabalho em equipa e ainda a defesa de ideias. Quanto à inversão de papéis entre alunos e professor, denotou-se que ambos conseguiram distanciar-se de hábitos originados num ensino tradicional, o que lhes permitiu trabalhar em parceria e construir as aprendizagens desejadas, num ambiente de maior interesse, empenho e motivação. Today's society has suffered enormous changes in recent years and because of this, the challenges of education are increasing. Nowadays students have greater access to information and, as such, it is necessary to rethink the methods that are used by teachers in the classroom, so that students can apply the diversity of knowledge they have and feel integrated in the process of the teaching and learning. This investigation work, was implemented in a class of 10th grade, the purpose was to get distance from the traditional practice, through the Problem Based Learning (PBL) and Georeferencing Google EarthTM program for the study of seismology. So, during the lessons which involved research, the opportunity was given to the students to construct their own knowledge through collaborative work. In general, the purpose of the research is to assess the skills that students develop during classes and check the performance of students and the teacher, since students are responsible for the construction of their learning and the teacher acts only as the tutor of the whole process. There fore, we used various techniques and data collection tools such as observation, document analysis and questionnaires. Through its analysis, it is concluded that the goals have been achieved, with students mainly achieving perfect skills such as decision making, synthesis power, autonomy, collection capacity and analysis of information, mutual aid, teamwork as well as protection ideas. As for the role reversal between students and teacher, it is noticed that both were able to get distance themselves from habits originated in traditional teaching, which allowed them to work in partnership and build the desired learning in an environment of greater interest, commitment and
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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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Martinsson, Lisbeth. "Barns föreställningar om dag- och nattcykeln : Har eleverna uppnått målen för år 5?" Thesis, Karlstad University, Faculty of Social and Life Sciences, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-862.
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Syftet med detta examensarbete är att ta reda på hur elevers uppfattningar om de rörelser som sker i vårt solsystem stämmer överens med de vetenskapliga fakta som finns. I våra vardagliga situationer refererar vi till det vi med ögats hjälp kan uppfatta i fråga om vad som rör sig eller ej. Hur påverkas eleverna av de dagliga uttryck som de får höra sedan de är mycket små, och har de en möjlighet att med skolans hjälp förändra dessa tankesätt?
Undersökningen genomfördes med hjälp av kvalitativa intervjuer av elever i skolår 1 respektive 5. Detta för att se hur stor skillnaden är mellan de elever som inte har erhållit någon undervisning om solsystemet och de elever som ska ha uppnått de mål för fysik som skolverket har ställt upp.
Eleverna som deltog i studien valdes slumpmässigt ur respektive klasser. De fick besvara 14 frågor, var och en för sig. De besvarade frågorna olika utförligt, vissa var mycket fåordiga. Ibland var jag tvungen att ställa följdfrågor, eftersom jag ville förstå eleverna på ett bra sätt.
Resultatet av undersökningen visar att elevernas kunskaper inom området har en stor variation, även inom samma åldrar. Detta kan härledas till elevernas eget intresse av vårt solsystem. Den slutsats som jag har dragit av undersökningen är att det är viktigt att ta reda på vilka föreställningar som eleverna har inför arbetet med arbetsområdet.
The purpose of this degree project is to find pupils´ understanding about the movements which occur in our solar system and compare them with the scientific facts we know about. In our daily life we refer to what we can see with the help from our eyes whether something moves or not. How do the pupils´ get affected by these daily expressions they hear from early ages, and do they have an opportunity with the help from the school to change these ways of thinking?
The survey was carried out with help of qualitative interviews of pupils´ in class 1 and 5. This because to see how large the difference is between pupils´ who hasn’t received any education about the solar system and the pupils´ who are supposed to have reached the goals compiled by The National Agency for Education.
The pupils´ who took part in this study were chosen by random from both classes. They answered to 14 questions, each and everyone on their own. They answered the questions with various details, some were very taciturn. Sometimes I had to ask resulting questions, since I wanted to understand the pupils´ properly.
The result of the survey shows that the pupils´ knowledge within the area have a large variation, even within the same ages. This can be deduced to the interest of the pupils´ in our solar system. The conclusion I have maid from this survey are that it is important to find out which understandings the pupils´ have before the work with the subject area.
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Kamoyo, Memory. "A review of the use of scientific knowledge in environmental impact assessment reports for dam construction." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-421468.
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It is estimated that 3,700 major dams are either planned or under construction, notably in developing countries. Dams can pose a threat to fish diversity, as one of the biggest impacts of damming is habitat fragmentation. Damming causes the isolation of small fish habitats, which reduces genetic diversity and expose fish species to vulnerability of local extinction, hence habitat fragmentation is one of the causes of biological loss. There are tools, which are used to balance between development and biodiversity conservation. One of the tools, which is commonly used, is environmental impact assessment (EIA). EIA uses both science and political knowledge. Science knowledge is important in EIA process as it is required to generate reliable baseline information, impact prediction and effective proposed mitigation. However, no studies have investigated the extent of the use of science knowledge in EIA for hydropower dams in Southern Africa. The purpose of this study is to examine the usage of scientific knowledge in environmental impact statements (EIS), focusing on EISs of dam construction on the impact of habitat fragmentation in fish. Ten EISs were collected from Lesotho, Malawi, Mozambique, Zambia, Zimbabwe. These countries were chosen because they are the hotspots for hydropower planning. I conducted EIS quality review to answer the research purpose. I adopted and used EIS quality review package, which was developed by Lee and Colley (1991), to assess the content and quality of EISs. The results show that the use of science knowledge varies from one EIS to the other, and from one area of review to the other. The baseline and mitigation areas of EISs aligned with the scientific consensus the best, while the identification, prediction and evaluation of impacts area is generally unsatisfactory. Overall, six EISs out of ten EISs use science in a satisfactory way, and four EISs are unsatisfactory, meaning they attempted or completely omitted methods for assessing the ecological concept of fragmentation. I recommend a comprehensive study to review the use biodiversity concepts and methods in EISs for all the dams in southern Africa.
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KHAN, WAQAR AHMAD. "FINITE ELEMENT METHOD BASED COMPARATIVE STUDY OF SEEPAGE IN EARTHEN DAM." Thesis, 2014. http://dspace.dtu.ac.in:8080/jspui/handle/repository/15409.
Full textAbstract:
Dams are the structures that are used for the storage of water. Its failure may
greatly affect the surrounding locality. Therefore, it is necessary to investigate the
causes of failure and use preservative measures by proper designing. Among various
causes, one of the major cause of failure is seepage. Seepage is an important issue that
needs to be considered before designing of an Embankment Dam. Seepage through
the body of the Embankment Dam adversely affects the stability of the Dam
In this thesis, Analysis of seepage is carried out using Finite Element Method.
Results obtained are then compared with Analytical Method. In this study, parametric
study was carried out with height and slope of the embankment being the variable.
Firstly, Analysis was carried out using Finite Element Method, then seepage
discharge was calculated numerically using Analytical Method and the results
obtained was compared. The result obtained using Finite Element method is about
12% greater than the result obtained using Analytical Method. It’s likely that the
result obtained using Finite Element Method is more realistic because it has greater
accuracy due to large discretization of structure and difference in result is due to
difference in method.
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Singh, Anshuman. "A Parametric Study of Slope Stability and Comparison of Breach Parameter for Different case of Earthen Dam." Thesis, 2018. http://ethesis.nitrkl.ac.in/9487/1/2018_MT_216CE1037_ASingh_Parametric.pdf.
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The slope stability analysis of earthen dam for every aspect is very crucial because huge risk is related to dam at every stage of construction and working period. The very huge volume of water stored in reservoir by dam, which is very hazardous to downstream location for worst-case scenarios at time of breach in dam. Therefore, stability of dam and breach scenarios is very important to analyze for better solution for dam construction technique. Stability of dam depend upon stress occur in different loading condition, strength of material, geometric parameter, type of foundation and equipment installed. In this study, comparison of downstream slope stability by varying material property of dam and slope of downstream of dam. The effect of core seize, shape, inclination and position on stability of dam. Factor of safety obtained from limit equilibrium and finite element method are compared for various case of dam. In addition, dam break analysis is done for comparing the effect of different breach parameter equation on downstream breach flood. In breach analysis of dam, type of dam and failure mechanism of dam also effect downstream breach flood is also studied.
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Dronamraju, Venkata Subrahmanyam. "Studies on field stabilization methods to prevent surficial slope failures of earthfill dams." 2008. http://hdl.handle.net/10106/1702.
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Esford, Fiona Colleen. "Heat flow through earth dams : a dam performance monitoring tool." Thesis, 2002. http://hdl.handle.net/2429/12449.
Full textAbstract:
Reservoirs located in temperate climates undergo seasonal temperature fluctuations, warm in the
summer and cold in the winter. As a result, the temperature of the water seeping through
embankment varies with the season. Heat from the reservoir propagates through dams by two
main processes: convection and conduction. The variation in seepage water temperature can be
used as a tracer to detect and monitor seepage flow through dams. Temperature measurements
from the saturated zone of dams have been collected and qualitative and simplified quantitative
methods of data analysis have been used to detect relative changes in the seepage regime.
This thesis used two dimensional, uncoupled (fluid and heat flows) numerical models to simulate
heat flow through dams and determine seepage velocities. The numerical programs used in this
thesis were SEEP/W and a modification of CTRAN/W, produced by GEO SLOPE International
Inc. of Calgary. The programs were run in succession, beginning with SEEP/W. The analytical
method was first tested by comparing results to a closed form solution simulating one
dimensional flow (heat and water) through a homogenous material. Secondly the numerical
method was applied to analyse heat flow through a field scale model dam in Germany, followed
by an analysis of BC Hydro's Coquitlam Dam.
The numerical method was successful in simulating one dimensional flow. The method was also
capable of simulating fluid and heat flow through the field scale dam, which had a simple
stratigraphy. However, the hydraulic conditions at Coquitlam Dam are more complex and a two
dimensional model was not able to account for the flow variations at this dam. A three
dimensional model appears necessary to accurately simulate the fluid and heat flow conditions of
Coquitlam Dam. Temperature data collected from Coquitlam Dam was qualitatively assessed.
No obvious signs of preferential seepage paths were detected.
Although the numerical models used in this thesis were shown to effectively model fluid and heat
flow, the three step process required to use these modelling programs became cumbersome for
more complicated flow conditions. It is recommended that an integrated program be utilized to
analyse complex systems, such as Coquitlam Dam.
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Chen, Chung-Fa, and 陳進發. "Seepage Simulation for Nanhua Earth Dam." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/2s5tpn.
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碩士逢甲大學
土木及水利工程所
90
We have got the monitoring datas of Nanhau earth dam. According to these monitoring datas. We got the distributions of the total head pressure and pore pressure. This study we used software package Seep2D model of the GMS to simulate stable type seepage. We compared and explored each other crossly by the results of simulations and monitoring datas. In order to understand the differences by this two datas. The results of the simulations and monitoring datas are almost the same at up and down stream. But the errors reach to 13% at the central parts of the earth dam, the reason is the central part of the earth dam was over compacted.（during the construction of dam） Totally speaking, we proof this model can be used to simulate the dam’s seepage. This is a great assistance for the dam’s safe-assessment by simulation of the whole dam’s distributions of the pore pressure and total head pressure.
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Lu, Chen-Chung, and 呂權峻. "Seismic Safety Assessment of Earth Dam." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/56588849786804535332.
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碩士國立臺灣大學
土木工程學研究所
92
Summery On 21 september 1999,Ji-ji occur an earthquake,measured 7.2 on the moment magnitude scale,which cause severe damage on many dams.People concern Dam''s safety a lot,so the research about seismic safety evaluation of a reservoir is urgent. In recent seismic safety evaluation of a reservoir,we mainly use pseudo-static analysis,which use a safety factor to represent a dam''s safety.But actually,the risk and uncertainty in any construction is inevitable.So,in the paper,we plan to use risk analysis to evaluate seismic safety of a reservoir and try to get better method of seismic safety evaluation of a reservoir. In the paper,we take Shi-Men dam as a example,and use concept of event tree.To consider the uncertainty of earthquake,we use seismic risk analysis;to consider destruction,we calculate slide quantity.Finally,we can use the relation between slide quantity and probability of detroyed degree to calculate the year-probability of different detroyed degree of a dam. After the research,we know the year-probability of different detroyed degree of a dam.This method is more meaningfal than pseudo-static analysis,and can be a major consultation when government want to make a risk policy or insurance company want to consider the seismic risk of reservoir.
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GUO, WAN-MU, and 郭萬木. "Overtopping risk for an earth dam." Thesis, 1989. http://ndltd.ncl.edu.tw/handle/53303955722663709589.
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BANTI, ERIKA. "A methodology for the seismic assessment of existing earth dams in Italy." Doctoral thesis, 2017. http://hdl.handle.net/2158/1105814.
Full textAbstract:
Many earth dams in Italy are located in seismic areas with a seismicity from moderate to high. Moreover, they were built several years ago when the seismic Italian zonation and the construction code were completely different. Their seismic stability has to be assessed in order to ensure the safety of urban areas in the downstream site near the reservoirs.
This thesis is aimed at defining a reliable and suitable methodology for the assessment of the ultimate and serviceability limit states of existing earth dams in the light of the new seismic zonation of Italy.
The core of the Thesis is a numerical study related to the investigation of the seismic response of earth dams using the finite element method.
The first step consisted in the validation of the numerical method. This was performed by comparing the experimental results obtained from two different centrifuge tests with those obtained from the numerical analyses. The main goal was to identify the most relevant influential factors and select the most appropriate constitutive models.
Secondly, a parametric study was carried out in order to quantify the influence of each relevant factor. The parametric study concerned two “ideal” existing strategic dams, which represent two typical dam sections in Italy. They are located in the south of Italy, in a site which is exposed to high seismic risk. A deterministic spectrum-compatibility method, customized to the actual Italian regulations on structures and dams (M.LL.PP., 2008 and M.LL.PP., 2014) and to the hazard of the aforementioned site, was adopted for the selection of the input time histories. Two dimensional finite models were set up to reproduce the geometric characterization of the dam structure and its foundation.
This parametric study provided a means to assess the effect of different parameters and scenarios on the seismic analysis of dams. To this aim, the results of the two dimensional analyses have been discussed focusing on the role of each factor on the response of earth dam subjected under seismic motion.