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[ES] El resalto hidráulico constituye uno de los fenómenos más complejos con aplicación en el campo de la ingeniería hidráulica. Por un lado, las propias características del resalto, entre las que se encuentran las grandes fluctuaciones turbulentas, la intensa entrada de aire y una disipación de energía muy significativa, contribuyen a su complejidad situando el conocimiento actual del fenómeno lejos de una comprensión total del mismo. Por otro lado, es precisamente la naturaleza disipadora de energía del resalto la que da lugar a su principal aplicación práctica. Así pues, la investigación que aquí se presenta trata de contribuir al conocimiento general del resalto hidráulico y su aplicación para disipar energía en cuencos amortiguadores de grandes presas. Para ello, se abordaron las bases del fenómeno mediante la caracterización de un resalto hidráulico clásico (RHC). La investigación se llevó a cabo bajo una doble perspectiva de modelación numérica y física. Se emplearon técnicas de Dinámica de Fluidos Computacional (DFC) para la realización de simulaciones de este resalto hidráulico, a la vez que se llevó a cabo una campaña experimental en un modelo físico específicamente diseñado para tratar el caso. De este modo, se abordaron los aspectos más relevantes del resalto hidráulico, incluyendo el ratio de calados conjugados, la eficiencia del resalto, la longitud de la zona de recirculación, el perfil de la lámina libre, las distribuciones de velocidad y presión, la longitud del resalto y el análisis de frecuencias. Los resultados de los modelos físico y numérico fueron comparados, no solo entre ellos, sino también con información de otros autores procedente de una extensa revisión bibliográfica. Ambos modelos mostraron su capacidad para representar con precisión el fenómeno estudiado. En base a este análisis se observa que la metodología empleada resulta adecuada para la investigación del fenómeno a estudiar. Una vez llevada a cabo la caracterización del RHC, se procedió a analizar un cuenco amortiguador para disipación de energía. En particular, se estudió un caso general y representativo de cuenco amortiguador tipificado USBR II, a partir de la doble perspectiva de modelación física y numérica. Asimismo, los resultados se compararon con datos y expresiones bibliográficas. Esta comparación pretendía evaluar los rasgos particulares del resalto hidráulico en cuencos amortiguadores de grandes presas, así como la influencia de los elementos disipadores de energía en el flujo. Todos los resultados mostraron estar en la línea de las investigaciones de otros autores, más allá de ciertas diferencias relativamente pequeñas. En consecuencia, la metodología desarrollada muestra su utilidad para abordar el estudio del flujo en cuencos amortiguadores. En concreto, los resultados presentados contribuyen a expandir el conocimiento sobre el RHC y el flujo en un cuenco amortiguador tipificado USBR II. Así pues, los resultados pueden emplearse para mejorar el diseño de estructuras de disipación de energía en grandes presas. Durante los últimos años, la adaptación de cuencos amortiguadores a caudales superiores a los empleados para su diseño ha ganado gran relevancia. Esta adaptación resulta clave por los efectos del cambio climáticos y las crecientes exigencias de la sociedad en materia de seguridad y protección frente a avenidas. De este modo, toda contribución a la modelación de resaltos hidráulicos, como la que aquí se presenta, resulta crucial para afrontar el reto de la adaptación de las estructuras hidráulicas para disipación de energía. / [EN] The hydraulic jump constitutes one of the most complex phenomena with application in hydraulic engineering. On the one hand, a series of features bound to the hydraulic jump nature, such as the large turbulent fluctuations, the intense air entrainment and the significant energy dissipation, contribute to build its complexity, which places the current knowledge far from a full understanding of the phenomenon. On the other hand, it is precisely this energy dissipating nature that justifies its use in large-dam stilling basins, which constitutes its main practical application. Hence, the research here presented aimed to contribute to the general knowledge of the hydraulic jump phenomenon and its application for energy dissipation purposes in large-dam stilling basins. To this end, the bases of the phenomenon were addressed by characterising a classical hydraulic jump (CHJ). The research was conducted under a double numerical and physical modelling approach. Computational Fluid Dynamics (CFD) techniques were employed to simulate the hydraulic jump, whereas an experimental campaign in a physical model designed for the purpose was carried out too. The most relevant hydraulic jump characteristics were investigated, including sequent depths ratio, hydraulic jump efficiency, roller length, free surface profile, distributions of velocity and pressure, hydraulic jump length and fluctuating variables. The results from the physical and the numerical models were compared not only between them, but also with bibliographic information coming from an extensive literature review. It was found that both modelling approaches were able to accurately represent the phenomenon under study. Once the characterisation of the CHJ was carried out, the analysis of an energy dissipation stilling basin was developed. In particular, a general and representative case study consisting in a typified USBR II stilling basin was analysed through a physical and numerical modelling approach. In addition, the modelled results were compared with data and expressions coming from a bibliographic review. This comparison was intended to assess the particular characteristics of the hydraulic jump in a large-dam stilling basin, as well as the affection of the energy dissipation devices to the flow. The results revealed not only similarities to the CHJ, but also the influence of the energy dissipation devices existing in the stilling basin, all in good agreement with bibliographic information, despite some slight differences. Consequently, the presented modelling approach showed to be a useful tool to address free surface flows occurring in stilling basins. In particular, the results reported contribute to the enhancement of the knowledge concerning the CHJ and the flow in a typified USBR II stilling basin. These results can be used to improve the design of large-dam energy dissipation structures. This is a key issue in hydraulic engineering, especially in the recent years. Thus, there is an increasing urgency for the adaptation of existing stilling basins, which must cope with higher discharges than those considered in their original design. The adaptation of these structures becomes even more important due to climate change effects and increasing society demands regarding security and flood protection. In these terms, contributions to hydraulic jump modelling, as the ones presented in this research, are crucial to face the challenge of energy dissipation structures adaptation. / [CA] El ressalt hidràulic constitueix un dels fenòmens de major complexitat amb aplicació en el camp de l'enginyeria hidràulica. D'una banda, les característiques del propi ressalt, com poden ser les grans fluctuacions turbulentes, la intensa entrada d'aire i una dissipació d'energia molt significativa, contribueixen a la seua complexitat, de manera que el coneixement actual del ressalt està lluny d'una comprensió total del mateix. D'altra banda, és precisament la gran dissipació d'energia associada al ressalt la que motiva la seua principal aplicació pràctica. La investigació que ací es presenta tracta de contribuir al coneixement general del ressalt hidràulic i la seua aplicació per dissipar energia al vas esmorteïdor de grans preses. En primer lloc, s'abordaren les bases del fenomen mitjançant la caracterització d'un ressalt hidràulic clàssic (RHC). La investigació es va dur a terme sota una doble perspectiva de modelització física i numèrica. El ressalt hidràulic es va simular emprant tècniques de Dinàmica de Fluids Computacional (DFC), mentre paral·lelament es desenvolupava una campanya experimental amb un model físic específicament dissenyat per tractar aquest cas. D'aquesta manera, es van abordar els aspectes més rellevants del ressalt, incloent el ràtio de calats conjugats, l'eficiència, la llargària de la regió de recirculació, el perfil de la superfície lliure, les distribucions de velocitat i pressió, la llargària del ressalt i l'anàlisi de freqüències. Els resultats dels models físic i numèric es compararen, no solament entre ells, sinó també amb informació procedent d'una extensa revisió bibliogràfica. Ambdós models van mostrar la seua capacitat per reproduir amb precisió el fenomen estudiat. Prenent aquest anàlisi, s'observa que la metodologia desenvolupada resulta apropiada per investigar fenòmens com el ressalt hidràulic. Caracteritzat el RHC, s'analitzà un vas esmorteïdor amb funció dissipadora d'energia. Concretament, s'estudià un cas general i representatiu de vas esmorteïdor tipificat USBR II, partint de la doble perspectiva de modelització física i numèrica. Així mateix, els resultats es van comparar amb dades i expressions bibliogràfiques. Aquesta comparació pretenia avaluar les particularitats del ressalt hidràulic al vas esmorteïdor de grans preses, així com la influència al flux dels elements dissipadors d'energia. D'aquesta manera, els resultats es situaren en la línia d'investigacions d'altes autors, més enllà de les lleugeres diferències reportades. En conseqüència, la metodologia desenvolupada mostra la seua utilitat per abordar l'estudi del flux en estructures de dissipació d'energia. En particular, els resultats contribueixen a expandir el coneixement relatiu al RHC i al flux en un vas esmorteïdor tipificat USBR II. Així, aquests resultats poden ser utilitzats per millorar el disseny de les estructures de dissipació d'energia de grans preses. Durant els últims anys, l'adaptació de vasos esmorteïdors a cabals superiors als considerats en la seua fase de disseny ha guanyat especial rellevància. Aquesta adaptació resulta crucial pels efectes del canvi climàtic i les creixents demandes de la societat en matèria de seguretat i protecció front a inundacions. En definitiva, tota contribució a la modelització de ressalts hidràulics, com la que ací es presenta, és de gran importància per afrontar el repte de l'adaptació d'estructures hidràuliques dissipadores d'energia. / The research here presented was funded by ‘Generalitat Valenciana predoctoral grants (Grant number [2015/7521])’, in collaboration with the European Social Funds and by the research project ‘La aireación del flujo y su implementación en prototipo para la mejora de la disipación de energía de la lámina vertiente por resalto hidráulico en distintos tipos de presas’ (BIA2017-85412-C2-1-R), funded by the Spanish Ministry of Economy in cooperation with European FEDER funds. / Macián Pérez, JF. (2020). Numerical and physical modelling approaches to the study of the hydraulic jump and its application in large-dam stilling basins [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/149565

The present work deals with the behavior of ancient railway sub-structure in France. A statistical study was firstly undertaken on problems occurred in the whole ancient French railway network. The analysis evidenced the particular importance of sub-grade quality for the performance of the sub-structure and the track geometry. Afterwards, an ancient railway line in the West of France was investigated. The analysis showed that the degradation speed of this line was correlated with different parameters such as the nature of sub-grades and the thickness of different layers. An increase trend of degradation speed with the increase in interlayer thickness was identified. The interlayer has a positive impact since it reduces the train-induced stress applied to the sub-grade. The hydro-mechanical behavior of interlayer soil under different conditions (water content, fines content, stress, number of cycles) was investigated. A set of triaxial tests and infiltration tests were performed for this purpose. By analyzing the shear strength properties, the permanent axial strain and the resilient modulus of interlayer soil, we found that the water content and the fines content must be considered together. Adding more fines into the interlayer presents a positive impact under unsaturated conditions thanks to the suction effect, but a negative impact under saturated conditions. The infiltration column tests with drying/wetting cycles showed that the hydraulic conductivity of interlayer soil is governed by fines fraction but did not change significantly with fines content. In order to study the mechanism of interlayer creation and mud pumping, a physical model of 550 mm inner diameter was developed. Soil samples representing the ancient French railway substructure with a ballast layer overlying an artificial silt layer (mixture of crushed sand and kaolin were tested. The effects of monotonic and cyclic loadings, water content and dry unit mass of sub-soil were investigated. It was found that the pore water pressure developed in the sub-soil and the sub-soil stiffness are the key factors for the migration of fine particles or the creation of interlayer/mud pumping. Water is the necessary condition, but it is the soil compressibility that governs the phenomenon to occur

[pt] Em geral a segurança das estruturas hidráulicas, em particular das barragens é muitas vezes ameaçada devido à formação de erosão próximo as fundações em conseqüência das altas velocidades dos jatos que partem dos vertedouros atingindo os maciços rochosos a jusante. O fenômeno de erosão envolve uma complexa interação entre processos hidráulicos e mecânicos. Um dos principais problemas no desenvolvimento dos métodos para estudo de erosões em rocha, esta associados ao entendimento dos complexos fenômenos físicos envolvidos no processo, cuja maioria não pode ser descritos e nem testados em escala de laboratório. A observação de fenômenos naturais, a avaliação do desempenho de estruturas hidráulicas, juntamente com a realização de experimentos em nível de laboratório e o desenvolvimento de modelos analíticos e numéricos têm contribuído muito para o entendimento dos mecanismos envolvidos no processo de erosão. Neste contexto, com o apoio da empresa Eletrobrás Furnas, o presente trabalho apresenta o desenvolvimento de um modelo físico implantado no laboratório de geotecnia da PUC-Rio, o qual possibilita a compreensão do processo físico de movimentação dos blocos rochosos durante a erosão, além da verificação e calibração de modelos numéricos a serem desenvolvidos. Inicialmente são abordados aspectos básicos sobre o comportamento mecânico e hidráulico dos maciços rochosos fraturados, evidenciando as propriedades das descontinuidades, além da importância destes aspectos no comportamento dos maciços ao efeito erosivo. O segundo capitulo apresenta o objeto de estudo deste trabalho, que é, o entendimento do fenômeno erosivo de maciços rochosos fraturados a jusante de dissipadores do tipo salto esqui, sendo abordado os aspectos hidráulicos e geomecânicos básicos envolvidos e os métodos existentes para a avaliação da erosão. O terceiro capítulo apresenta a proposta da célula cilíndrica desenvolvida, sendo descrito aspectos importantes, tais como a escolha do tipo de material, detalhamento e dimensionamento da célula. O próximo capítulo tem como intuito principal apresentar inicialmente os diferentes equipamentos utilizados nos ensaios juntamente com o sistema de aquisição de dados desenvolvido. Sendo também apresentada a metodologia utilizada para execução dos ensaios. O penúltimo capítulo apresenta a descrição dos ensaios realizados, os quais buscaram o melhor entendimento comportamento dos blocos rochosos durante o processo erosivo que ocorre a jusante de vertedouros. Os resultados experimentais obtidos pelo modelo físico desenvolvidos são apresentados, mostrando que é um importante equipamento de análise experimental para a previsão de processos erosivos a jusante de vertedouros, mas que também pode servir como suporte para a verificação e a calibração de modelos numéricos a serem desenvolvidos, os quais poderão servir como medidas de engenharia para mitigação do fenômeno erosivo. / [en] In general the safety of hydraulic structures, particularly dams is often threatened due to the formation of erosion around the foundations as a result of high speeds of the jets leaving the spillways reaching solid rock downstream.The erosion phenomenon involves a complex interaction between processes hydraulic and mechanical. A major problem in developing methods for study of erosion in rock, associated with this understanding of complex physical phenomena involved in the process, most of which can not be described nor tested in scale laboratory.The observation of natural phenomena, the performance evaluation of hydraulic structures, along with performing experiments in laboratory level and the development of analytical models and numbers have contributed greatly to the understanding of the mechanisms involved in the process of erosion.In this context, with the support of the company Eletrobrás Furnas, this paper presents the development of a physical model implemented in geotechnical laboratory at PUC-Rio, which furthers our understanding of physical process of transferring blocks of rocks during erosion, beyond verification and calibration of numerical models to be developed.Initially, it discusses basic aspects of the behavior mechanical and hydraulic fractured rock masses, showing the properties of the discontinuities and the importance of these aspects in behavior of the massive erosive effect.The second chapter presents the object of the present study, that is, the understanding of the phenomenon of erosive fractured rock masses downstream sinks like ski jumping, and discussed aspects basic hydraulic and geomechanical involved and existing methods for the assessment of erosion.The third chapter presents the proposal of the cylindrical cell developed as described important aspects such as choice the type of material, detail and scale of the cell.The next chapter is the primary purpose to present initially different equipment used in the tests with the system developed data acquisition. Is also presented methodology used to perform tests. The penultimate chapter presents a description of the tests, the which sought to better understand the behavior of rock blocks during the erosion process that occurs downstream of spillways. The experimental results obtained by physical model is developed presented, showing that it is an important analytical equipment experimental prediction of erosion downstream spillway, but it can also serve as support for verification and calibration of numerical models to be developed, which can serve as engineering measures to mitigate the erosion phenomenon.

A presente tese versa sobre ampla investigação em torno da distribuição das ações verticais entre paredes de alvenaria estrutural dentro de um edifício. O edifício foi caracterizado como pertencente ao sistema complexo de paredes, o qual é de uso mais comum no Brasil. Desenvolveu-se análise numérica no edifício, com objetivo de predizer o comportamento na análise experimental, assim como na comparação entre os próprios modelos numéricos. Serviu de modelo experimental um edifício em escala real, o qual foi monitorado, durante sua execução e depois dela, com ensaio de prova de carga. Realizou-se monitoramento mediante uso de unidades especiais de alvenaria instrumentadas para se converterem em células de carga, nas quais as tensões em cada ponto de análise puderam ser determinadas. Tabelas e gráficos foram montados para tornarem possível a verificação das diferenças entre todos os modelos analisados. Como principais conclusões uma se mostrou de grande importância e foi esta: as paredes sofrem efeito da flexão e a causa são as rotações nas lajes apoiadas por elas. / The present thesis contemplated a wide investigation about the vertical action distribution among structural masonry walls within a building. The building was characterized as related to the complex system of walls, which practice is the most customary in Brazil. It was developed a numerical analysis in the building aiming to predict the structural behavior on the experimental analysis, as well as a comparison among numerical models themselves. The experimental model consisted on a real scale building, which was monitored during its execution and after that, with a live load test. The monitoring was done with the usage of special masonry units, which were instrumented to convert itself in a load cell, on which the stress in each point of analysis could be determined. Tables and graphics were mounted to make feasible to verify the differences among all models analyzed. As main conclusions observed, one showed to be of great importance, which was the effect of bending on the walls caused by the rotations on the slabs supported by them.

O método de injeção de ar é utilizado para a descontaminação de solos e lençóis freáticos contaminados com Compostos Orgânicos Voláteis (VOCs). O ar injetado no solo na zona saturada, ao subir para a zona não saturada, volatiliza os contaminantes. A eficiência da remediação por esse método está diretamente ligada à região de solo em que ocorre o fluxo de ar. Essa região é denominada de zona de influência e é afetada por vários fatores tais como: tipo e estrutura do solo, permeabilidade e pressão de injeção. No presente trabalho foram realizados estudos de fluxo de ar em solos saturados em um modelo físico bidimensional com o objetivo de avaliar a zona de influência formada. Os ensaios bidimensionais têm por finalidade a visualização dessa zona de influência; para isso foi utilizado um tanque transparente feito de placas de acrílico. Para a realização dos ensaios foram utilizados três tipos distintos de solo, uma areia natural denominada de Areia Osasco, uma areia comercial e uniforme (Areia do IPT) e um solo residual utilizado para criar as lentes de baixa permeabilidade. Também foram realizados ensaios de laboratório para a caracterização dos solos em estudo, tais como: curva de retenção, índice de vazios máximo e mínimo, granulometria, permeabilidade a água e ao ar. Os ensaios realizados no modelo (tanque) mostraram, como visto na literatura, que a granulometria e a estrutura do solo são as principais responsáveis pela formação de caminhos preferenciais de ar no solo. A zona de influência formada durante a injeção de ar nos ensaios com a Areia Osasco não foi simétrica devido à heterogeneidade do solo, já a formada nos ensaios com a Areia do IPT foi simétrica por causa da uniformidade do solo. A Areia do IPT apresentou uma zona de influência mais estreita do que a da Areia Osasco, isso ocorreu em função da menor porosidade da Areia Osasco, pois quanto menor a porosidade maior a tortuosidade e maior a expansão lateral. Os ensaios com as lentes de baixa permeabilidade mostraram que pequenas variações na configuração do solo podem influenciar a eficiência do método já que a região logo acima das lentes não foi atingida pelo ar. O aumento da pressão de injeção durante os ensaios fez com que mais canais de ar fossem formados causando um aumento do tamanho da zona de influência. / The method of air sparging is used for remediation of soil and groundwater contaminated with Volatile Organic Compounds (VOCs). In this process the air is injected into the soil in the saturated zone to ascend to the vadose zone and volatilizes the contaminants. The efficiency of air flow remediation is directly linked with the region of soil in which the flow occurs. This region is called as zone of influence and is affected by several factors such as: type and structure of the soil, permeability and pressure of injection. In the present work the air flow in saturated soils was investigated using a bidimensional physical model to evaluate the zone of influence formed. The objective of the tests was to obtain informations about zone of influence. A transparent tank made by acrylic plates was used. For these tests it was used three different types of soil: natural sand, called Osasco sand, a commercial and uniform sand called IPT sand and a residual soil used to create the lenses with low permeability. Laboratory tests such as water retention, minimum and maximum voids ratio, water and air permeability were performed to characterize the soils used in this study. Tests performed in the model (tank) showed, like those in the literature, that the particle size and soil structure are mainly responsible to create the preferential paths of air in soil. The zone of influence formed during the injection of air in the tests with Osasco sand was not symmetrical due to the heterogeneity of the soil; on the other hand the test performed with IPT sand was symmetrical due to its uniformity. The IPT sand showed a narrower zone of influence than Osasco sand, this was due to the lower porosity of the Osasco sand. Lower porosity imply in higher tortuosity and greater lateral expansion. Testes performed with low permeability lenses within the sand showed that small variations in the structure of the soil can affect the efficiency of the method because the region immediately above the lens is not reached by the air. The increase in the pressure of injection during the experiments induced the formation of more air channels causing an increase in the size of the zone of influence.

Interest in exploring renewable energy resources has increased globally, especially with recent worldwide intentions to maintain the global climate. Looking at the oceans as a vast sustainable clean energy resource to satisfy present high humankind energy demands has been strongly recommended. Several types of renewable energy resources exist in the oceans: waves, tides, thermal and salinity variations, currents, and offshore winds. Exploiting tidal currents is considered one of the most effective approaches to the generation of electricity. Tidal turbines are deployed beneath the sea surface to transfer the kinetic energy in tidal currents to mechanical energy suitable for ongoing conversion to electricity and subsequent transmission. However, choosing a suitable site to deploy these turbines is not a trivial process. Various constraints must be satisfied subject to basic criteria dependent upon local factors, technology limitation and economic consideration. In addition, an important issue to consider is taking care to harness energy from tidal currents with minimum possible impact on the surrounding environment. The present study justifies the nomination of the Strait of Messina as an exceptional tidal current energy resource within the Mediterranean Sea basin. The maximum tidal current velocity at spring peak tide through the Strait may exceed 3 m/s. This mainly results from the tidal phase-difference (180°) between the northern (Tyrrhenian Sea) and southern (Ionian Sea) tips of the Strait, associated with a difference of 0.27 m in tidal wave amplitudes. In addition, the complex coastline configuration of the Strait plays an important role in enhancing tidal current velocities. Therefore, the Strait of Messina fulfils the basic criterion (2 m/s tidal current velocity) to be considered as a valid tidal current energy resource. This massive tidal current energy resource is assessed in the present study. A detailed full desk-based Environmental Impact Assessment (EIA) study is performed using the interactive matrix approach in order to investigate the anticipated environmental impacts on the marine ecosystem of the Strait of Messina resulting from the harnessing of energy from its tidal currents. Through the EIA study the different environmental components, both biotic and abiotic, which may be affected by the energy extraction process, are explained. In addition, the proposed key project activities are listed; the likelihood of occurrence and the magnitude of impact interaction with the environmental components are evaluated. The final judgment matrix guides to make a right decision on the proposed project. From the resulted matrix, the major impacts do not exceed 10% of the total anticipated effects. The positive point is that all the expected impacts, including the majors, can be controlled and minimised to the lowest possible limits by applying a good monitoring programme. The University of Edinburgh “Tidal Flow Development (TFD)” numerical model is used to mimic the tidal environment of the Strait of Messina in different cases. The model successfully simulates the tidal flow regime within the Strait under some exceptional conditions. Modifications to the main numerical code and coefficients were necessary in the present research to adjust the model according to each case study. In the three different cases of simulation, using these exceptional coefficients, the model simulates the main tidal characteristics of the tidal flow within the Strait. According to the results of the numerical simulation process, tidal currents are more intensive close to the eastern coast of the Strait of Messina near to Punta Pezzo. This area is far from any ferry route between Italy and Sicily. The best location to deploy tidal turbines for the energy extraction process is therefore recommended to be within these surroundings. Finally, a physical (laboratory) model is used to simulate the flow regime within the Strait of Messina. The Particle Image Velocimetry (PIV) technique was applied in the flow-table tank at the University of Edinburgh. The physical model simulates the flow behaviour within the Strait of Messina to a satisfactory degree. The cyclonic and anti-cyclonic motions observed at the southern extremity of the Strait are also very well simulated. The results of the present study assure confidence in the use of tidal currents within the Strait of Messina as a renewable energy resource. The safety of the environment must be ensured by following environmental guidelines, respecting the energy extraction limits and by applying an effective monitoring programme. The later is strongly recommended to be an adaptive one in which higher environmental authorities are able to watch, revise and control the environmental team within the project. These authorities are also able to postpone the project in case of any severe environmental case. The simulation processes emphasize the effect of morphometry and topography in enhancing tidal currents in the Strait of Messina. Moreover, numerical simulation assures that the complex morphometry and bathymetry, in addition to the open boundaries of the Strait of Messina, are challenging issues for modellers in order to mimic the real tidal current resource in the case of the Strait of Messina. The study also strongly recommends applying a more effective numerical model than TFD to assess the tidal hydrodynamical environment before and after any proposed energy extraction process. This will certainly, with the EIA of the marine ecosystem, help to make a right decision about the proposed project in order to achieve the goal of using clean and clear renewable energy resources while maintaining both natural and hydrodynamical environments to the most possible safest degree.

Baigiamajame magistro darbe kuriamas dviejų polių įgilinimo metu atsirandančių grunto masyvo deformacijų fizinis modelis, įvertinus užsienio šalių patirtį šioje srityje. Išnagrinėti pagrindiniai principai, kuriais remiantis buvo sudarytas fizinis modelis moreniniuose gruntuose. Pateikta eksperimentinės aikštelės fizinė geografinė padėtis, geologinė litologinė sandara, grunto fizikinės ir mechaninės savybės, hidrogeologinės sąlygos, modelio sudarymo metodika, laboratorinių bei lauko bandymų rezultatų analizė. Įvertinus teorinius ir praktiškai gautus fizinio modelio aspektus, pateikiamos baigiamojo darbo išvados ir siūlymai. / The thesis developed a two-pile įgilinimo the resulting array of soil physical deformation model, the assessment of foreign experience in this field. The main principles, which were drawn up in a physical model of morene soil. Submitted to the experimental site physical geographical location, geological lotological structure, soil physical mechanical characteristics, hydrogeological conditions, design methodologies, laboratory and field test results of the analysis. The assessment of the theoretical and practical aspects of the model obtained by physical, the conclusions and suggestions. The work consists of three parts: introduction, World of impact and interaction of soil physical models for review, installed by vibro pile and soil interaction physical model, the theoretical pile and soil interaction model, conclusions, references.

the 18th World Congress The International Federation of Automatic Control, Milano (Italy), August 28 - September 2, 2011

Local scour around bridge foundations has been recognized as one of the main causes of bridge failures. The objective of this study is to investigate the relationships among field, laboratory, and numerical data for the purpose of improving scour prediction methods for complex bridge piers. In this study, three field sites in Georgia were selected for continuous monitoring and associated laboratory models were fabricated with physical scale ratios that modeled the full river and bridge cross sections to consider the effect of river bathymetry and bridge geometry. Three different sizes of sediment and several geometric scales of the bridge pier models were used in this study to investigate the scaling effect of relative sediment size, which is defined as the ratio of the pier width to the median sediment size. The velocity field for each bridge model was measured by the acoustic Doppler velocimeter (ADV) to explain the complicated hydrodynamics of the flow field around bridge piers as guided by the results from a numerical model. In each physical model with river bathymetry, the comparison between the results of laboratory experiments and the measurements of prototype bridge pier scour showed good agreement for the maximum pier scour depth at the nose of the pier as well as for the velocity distribution upstream of each bridge pier bent. Accepted scour prediction formulae were evaluated by comparison with extensive laboratory and field data. The effect of relative sediment size on the local pier scour depth was examined and a modified relationship between the local pier scour depth and the relative sediment size was presented. A useful methodology for designing physical models was developed to reproduce and predict local scour depth around complex piers considering Froude number similarity, flow intensity, and relative sediment size.