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Conlee, Carolyn T. Gallagher Patricia M. „Dynamic properties of colloidal silica soils using centrifuge model tests and a full-scale field test /“. Philadelphia, Pa. : Drexel University, 2010. http://hdl.handle.net/1860/3248.
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Roia, Davide. „Dynamic response of piles under lateral loading: full scale field test and numerical analysis“. Doctoral thesis, Università Politecnica delle Marche, 2011. http://hdl.handle.net/11566/241933.
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Negli ultimi anni il tema dell’interazione terreno-struttura ha suscitato un’attenzione
particolare nel campo dell’ingegneria geotecnica e strutturale. Le caratteristiche dinamiche del sistema terreno-fondazione possono condizionare fortemente il comportamento sismico della struttura di elevazione. Questo problema è particolarmente importante nel caso di
fondazioni profonde: le proprietà meccaniche e la geometria del terreno e delle fondazioni,così come la loro mutua interazione, possono influenzare le caratteristiche di rigidezza e
smorzamento del sistema suolo-palo durante il moto sismico.
Sia nella ricerca che nella progettazione avanzata questo problema può essere studiato in modo diretto, modellando l’intero sistema dinamico suolo-palo con un modello 3D agli
elementi finiti, o utilizzando metodi teorici. I risultati di questi approcci sono molto sensibili al grado di dettaglio del modello e a molti parametri che definiscono le caratteristiche dinamiche del sistema terreno-palo. In questo contesto, i risultati di test
sperimentali in situ, in vera grandezza o in scala ridotta, e i risultati di test di laboratorio rappresentano uno strumento essenziale per fornire i parametri necessari ai modelli numerici e analitici e per validarne i risultati. Tuttavia, in letteratura non sono molti i lavori
che riguardano prove in situ in vera grandezza su fondazioni profonde.
Questo lavoro presenta un esteso programma di prove sperimentali in situ in vera grandezza condotto su un gruppo di tre pali in acciaio al porto turistico di La Spezia, in Italia. Il programma comprende tre tipologie di prove dinamiche con differenti livelli di eccitazione:
prove di impatto, prove di vibrazione libera e di vibrazione forzata. I pali sono vibro-infissi in argilla marina soffice in una configurazione ad L e non sono vincolati in testa. Il programma di prove è stato eseguito in due tempi: la prima campagna una settimana dopo la vibro-infissione dei pali e la seconda dopo dieci settimane. I pali sono stati strumentati
con accelerometri disposti in testa a ciascun palo e con strain gages e trasduttori di pressione disposti lungo il palo d’angolo, utilizzando una tecnica non convenzionale per prove in sito in ambiente marino. Viene presentato e discusso il comportamento dinamico
del complesso sistema suolo-acqua-palo soggetto a diversi livelli di forza. Con riferimento al palo singolo, ne viene presentata la risposta in termini di frequenze naturali, smorzamenti
e forme modali dei primi due modi flessionali. Con riferimento al gruppo di pali sono valutati gli effetti dell’interazione palo-palo dovuti alla propagazione di diversi tipi di onde,
in relazione alla direzione dell’azione. Si discute la variazione del comportamento dinamico del sistema nel tempo (per le due campagne di prove) dovuta alla ri-consolidazione del terreno vicino ai pali susseguente la vibro-infissione. Inoltre, viene effettuata una stima
della velocità delle onde di taglio dello strato di terreno superficiale sulla base della misurazione dei ritardi temporali dei segnali accelerometrici alla testa dei pali. I risultati sperimentali sono inoltre confrontati con quelli ottenuti mediante differenti approcci numerici: in particolare sono stati sviluppati due differenti modelli 3D agli elementi finiti in ABAQUS, considerando elementi di tipo solido o di tipo shell per la modellazione dei pali,
i cui parametri sono calibrati sulla base dei risultati sperimentali. Infine si mostrano i confronti con i risultati ottenuti mediante il modello 3D per l’analisi cinematica di
fondazioni su pali formulato da Dezi et al. (2009), opportunamente modificato al fine di
simulare le prove della campagna sperimentale.The topic of soil-structure interaction has received large attention in recent years. The seismic performance of a superstructure can be significantly affected by the behaviour of soil and foundation and their mutual interaction under an earthquake motion. This problem is particularly significant in the case of deep foundations; mechanical properties and geometrical characteristics of soil and piles as well as their mutual interaction may affect the stiffness and damping characteristics of the soil-pile system during earthquake motion.In both research and advanced practice, this problem may be approached with a direct method, modelling the whole dynamic soil-pile system with a 3-D finite element model, or by using theoretical approaches. However, the results of these approaches are very sensitive to the degree of the model refinement and to many parameters that define the dynamic characteristics of the soil-pile system. In this context, experimental results of full- or smallscale in situ and laboratory tests represent an essential instrument to provide parameters for and to validate numerical and analytical methods. However, few full-scale in-situ tests on pile foundations have been reported in the open literature to date. The present work presents an extensive experimental program of full-scale field tests carried out on a group of three steel pipe piles at the tourist port of La Spezia, Italy. Three typologies of dynamic tests are carried out at different level of force: impact load test, free vibration test, and forced vibration test. The piles are vibro-driven into marine soft clay, with a L-shaped plan layout, kept free at the head. Two test campaigns have been carried out, the first 1 week and the second 10 weeks after vibro-driving of the piles. The piles are instrumented with an unconventional technique for field tests in marine environment which includes accelerometers at the head of each pile, strain gages and pore pressure gages along the fully instrumented corner pile. The dynamic behaviour of the complex soil-water-pile system at different levels of force is discussed. In particular the response of the single pile, in terms of natural frequencies, damping and mode shapes of the first and second pile bending modes is presented. Effects of the input direction in the pile-to-pile interaction are also evaluated. The variation in time of the dynamic behaviour of the system (for the two campaigns), due to re-consolidation of the soil close to the pile subsequent to the vibrodriving, is observed. An average shear wave velocity of the upper soil is estimated from the time delays of the accelerometer signals recorded at the head of piles. The experimental results are then compared with numerical results obtained with different approaches: two 3-D finite element models are developed in ABAQUS, considering solid or shell elements for the piles, and calibrated on the basis of experimental results; and a 3-D model for the kinematic interaction analysis of pile groups, formulated by Dezi et al. (2009) is here specialized to simulate the tests of the experimental campaign.
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Delaney, Michael A. „Numerical field model simulation of full scale fire tests in a closed and an open compartment“. Thesis, Monterey, California. Naval Postgraduate School, 1992. http://hdl.handle.net/10945/23994.
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Thorbjörnson, Lind Thomas. „Rockfalls from rock cuts beside Swedish railroads : A full scale fieldtest, to investigate rockfalls and how rock bounces“. Thesis, KTH, Jord- och bergmekanik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-185583.
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Rockfalls is a major problem around the world, if they occur in populated areas, they can cause major damage to infrastructure, injure or kill people. For this reason, it is important to be able to predict where the risk of rockfalls and how to prevent and protect populated areas from them. However, it is no easy task to predict rockfalls. Although if an area with potential area for rockfall is localized it may seem easy to construct protective meshing or bolting potential blocks down. But in many cases this is not easy to do due to practical issues or economic reasons, for example in rock cuts on older railways in Sweden. Fall heights from rock cuts like that are not particularly high but the risk of damage to the trains and infrastructure in the track area is high, however, it is unknown how extensive the damage may be. Trafikverket, the Swedish authority responsible for Sweden's roads and railways, has for some years investigated a new method for classifying and minimize the risk of rockfalls from rock cuts next to the railways. This study include aims to include the potential maximum distance of a block from the rockfall can travel to the existing method. This master's work is part of the investigation and will include full scale field test where the rockfalls are examined by filming them and then evaluate the “bounce coefficient”, coefficient of restitution, from the individual rockfalls using photogrammetric methods. During the field study, a geotechnical testing equipment, DCP test rig, to be evaluated for its ability of an easy way in the field to produce an estimated value on the coefficient of restitution. During the evaluation, two rockfall simulating software be used to investigate how well the results from them match the true blocks movements.Stenras är ett stort problem runtom i världen, om de inträffar i bebyggda områden kan de leda till stora skador på infrastruktur, skador eller dödsfall. Av den anledningen är det viktigt att kunna förutse vart det finns risk för stenras och hur man kan förebygga dem och skydda bebyggda områden från dem. Dock är det ingen lätt uppgift att förutse stenras. Även om det finns ett potentiellt område för stenras kan det tyckas lätt att placera ut skyddsnät eller bulta fast potentiella block. Men i många fall är detta inte praktiskt, eller ekonomiskt, till exempel i bergsskärningar på äldre järnvägar i Sverige. Fallhöjderna här är inte speciellt höga men risken för skador på tåg och infrastruktur i spårområdet är hög, dock är det okänt hur omfattande skadorna kan bli. Trafikverket, den svenska myndigheten som ansvarar för Sveriges vägar och järnvägar, har under flera år utrett en ny metod för att klassificera och minimera riskerna för stenras från bergskärningar bredvid järnvägar. Denna utredning syftar bland annat till att till att väga in det potentiella maximalt avstånd ett block från stenras kan färdas i den befintliga modellen. Det här mastersarbetet är en del i den utredningen och kommer att innefatta ett fullskaligt fältförsök där stenras undersöks genom att de filmas och sedan utvärderas studskoefficienten, coefficient of restitution, från de enskilda rasen i stereo. Under fältstudien kommer en geoteknisk testutrustning, DCP test rigg, att utvärderas för sin förmåga att lätt i fält få fram ett uppskattat värde på studskoefficienten. Under utvärderingen kommer två stenrassimuleringsprogram att användas för att undersöka hur väl de stämmer med de verkliga blockens rörelser.
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McCarthy, Timothy G. „Numerical field model simulation of full-scale fire tests in a closed spherical/cylindrical vessel using advanced computer graphics techniques“. Thesis, Monterey, California. Naval Postgraduate School, 1991. http://hdl.handle.net/10945/26656.
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Camargo, Felipe Filizzola. „Field and laboratory performance evaluation of a field-blended rubber asphalt“. Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/3/3138/tde-01072016-111905/.
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Rubber asphalt has been used in Brazil as early as 2001. Among the fabrication processes of rubber asphalt, the most widely used in Brazil is the terminal blend. However, the use of field-blended rubber asphalt has been around in the United States for decades, especially in the state of Arizona. This process results in a highly viscous material with enhanced engineering properties, but requires specific equipment that is typically installed at the job site, or close to the supplying asphalt plant. Thus, keeping in mind the possible technological advantages of using a field blended rubber asphalt mixture and the lack of information regarding this technique in Brazil, there is a necessity to develop studies to assess the performance of this type of material in our environmental conditions and axle loading configurations. Therefore, a laboratory study was conducted to determine the rheological properties of a field-blended rubber asphalt and compare them to those of typical binders used in Brazil (an AC 30/45 penetration grade and a binder modified with SBS, an elastomeric polymer). Binder permanent deformation was determined using the Multiple Stress Creep and Recovery (MSCR) test, whereas binder fatigue behavior was determined using the Time Sweep and Linear Amplitude Sweep (LAS) tests. Subsequently, the permanent deformation and fatigue behavior of a gap-graded mixture using the field-blended rubber asphalt were assessed in the laboratory and in the field. The permanent deformation of the mixture was determined in the laboratory using the LCPC wheel track test, whereas the fatigue behavior was determined using the four point bending flexural test. A test section was built after the rehabilitation job of highway RJ-122, where a field-blended rubber asphalt mixture was first used in the country. The mixture performance was studied in situ through accelerated pavement tests using a full scale, large mobile traffic simulator. The results were used to model the performance of the structure with the rubber asphalt mixture by means of the Highway Development and Management Model (HDM-4) cracking and permanent deformation models, calibrated to local conditions. Accelerated pavement tests were validated through periodic pavement monitoring campaigns conducted for four years in a test section in Highway RJ-122. The field-blended rubber asphalt showed a good performance in terms of permanent deformation and fatigue determined in the laboratory at the binder and mixture levels, which confirms what was verified in the field.No Brasil, o asfalto-borracha vem sendo utilizado desde meados de 2001. Dentre os processos de fabricação do asfalto-borracha, o mais utilizado no Brasil é o asfalto-borracha estocável ou terminal blend. Contudo, o asfalto-borracha do tipo não estocável (field blend) vem sendo bastante difundido nos Estados Unidos há décadas, principalmente no estado do Arizona. Este processo resulta em um asfalto-borracha de alta viscosidade, com alto desempenho, porém requer um equipamento de fabricação de asfalto-borracha específico, instalado no canteiro de obras, ou muito próximo à usina de asfaltos fornecedora da obra. Tendo em vista as possíveis vantagens tecnológicas do asfalto-borracha field blend e o conhecimento ainda pequeno sobre esta técnica no Brasil, há a necessidade de desenvolver estudos para a avaliação deste tipo de material frente às condições climáticas e de solicitação pelas cargas viárias em nosso país. Para tanto, foi realizado um estudo em laboratório para verificar as propriedades reológicas de um asfalto-borracha field blend e compará-las com as características de ligantes típicos empregados no Brasil (um CAP 30-45 e um ligante modificado por polímero elastomérico do tipo SBS). Elegeu-se o Multiple Stress Creep and Recovery (MSCR) para verificar a deformação permanente e o Time Sweep e Linear Amplitude Sweep (LAS) para verificar o comportamento na fadiga dos ligantes. Na sequência, determinou-se a deformação permanente e o comportamento à fadiga de uma mistura asfáltica descontínua (gap-graded) empregando o asfalto-borracha field blend em laboratório e no campo. A deformação permanente da mistura foi verificada por meio do simulador de tráfego LCPC, enquanto a vida de fadiga foi determinada utilizando o ensaio de flexão em viga (4 pontos). Por fim, foi construída uma seção teste após a conclusão da obra de restauração dos pavimentos da rodovia RJ-122, local onde se elegeu a utilização desta tecnologia pela primeira vez no país. O desempenho da mistura foi estudado in loco com o emprego de ensaios acelerados do pavimento utilizando-se o simulador de tráfego linear móvel em tamanho real. Os resultados obtidos foram utilizados para modelar o desempenho da estrutura com o revestimento asfáltico constituído pela mistura com o asfalto-borracha por meio dos modelos de trincamento e de deformação permanente do Highway Development and Management Model (HDM-4), podendo-se verificar o desempenho desta mistura calibrado para as condições locais. Os ensaios acelerados foram validados em campo por meio de campanhas de monitoramento periódicas realizadas ao longo de quatro anos na rodovia RJ-122. Pelos ensaios de laboratório no ligante e na mistura foi possível concluir que o asfalto-borracha field blend apresenta um bom desempenho quanto à deformação permanente e à fadiga, corroborando o que foi verificado no campo.
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Freuler, Richard Jeffrey. „An investigation of jet engine test cell aerodynamics by means of scale model test studies with comparisons to full-scale test results /“. The Ohio State University, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487758680159803.
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Carrea, Francesco. „Shake-table test on a full-scale bridge reinforced concrete column“. Master's thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amslaurea.unibo.it/1756/.
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Gustafsson, Veronica. „Creep deformation of rockfill : Back analysis of a full scale test“. Thesis, KTH, Jord- och bergmekanik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-159189.
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With the purpose of studying the mechanical properties of uncompacted rockfill and the creep deformation behaviour of rockfill under a load as well as finding a suitable method for estimation of creep deformation behaviour, a full scale embankment loading experiment was performed. The results of this experiment were then evaluated. During the course of this study it became evident to the author that the deformations which were seen in the collected data from the experiment could be classified as creep deformations due to the linear decrease of the deformation against the logarithm of time and the study therefore came to focus on creep. One constitutive equation and one model for estimation of creep deformations were studied, and parameters were obtained through back analysis of experiment data as well as calculation of soil stresses. The creep model was based on a logarithmic approximation of the creep deformations and the creep equation was based on a power function. The creep model could also be simplified and evaluated as an equation and when a comparison was made between the equations and the measured results this showed that the logarithmic equation resulted in estimates closer to the measured deformations than what the power function did, therefore a logarithmic function is a better approximation to the deformations of the rockfill at Norvik than the power function. When the creep model was evaluated as intended, based on the soil stresses, the resulting creep estimates were less accurate, they was however still within the limits of what can be considered as admissible. The conclusion is that a logarithmic function describes the creep deformation of the rockfill at Norvik better than a power function and that the creep model by Kristensen is suitable for estimating the creep deformations. This since the creep model also provides a way of estimating deformations occurring under stress conditions other than the ones for which the creep test was performed.
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Edin, Erik, und Mattias Ström. „Comparing a full scale test with FDS, FireFOAM, McCaffrey & Eurocode“. Thesis, Luleå tekniska universitet, Byggkonstruktion och brand, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-75616.
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In the rapidly growing field of CFD-calculations (Computational Fluid Dynamics), companies and organizations are bringing forth new tools, tools that display an image of a given fire scenario. These tools are developed because they provide time efficiency as well as a sustainable economic approach. Another useful tool is analytical solutions, these analytical solutions serve the same purpose as CFD-modeling, providing results of a given scenario. The purpose of this thesis was to simulate a fire plume with two different CFDprograms and compare the gas temperature from each simulation with a full-scale test. Also, analytical solutions were used to perform the same comparisons. Four different calculation models were utilized to obtain results. The CFD-programs were FDS (Fire Dynamics Simulator) and FireFOAM. The analytical solutions were performed using McCaffrey´s plume equation and Eurocode solutions for localized fire temperatures. FDS is a very well documented program, due to this, problems that arose were easily fixed. The structure of FDS enables the user to maneuver the program easily. SmokeView was used to visualize the simulation. FireFOAM is written in C++ and is operated through the command prompt. The structure of the program was time-consuming to understand mainly because of two reasons, primarily because the authors lack of knowledge in coding in C++, and second because of the LINUX environment. Moreover, the process of working in FireFOAM was mostly through trial and error. On some occasions, issues arose that could be solved by communication with other CFD users at CFD-Online. When major problems occurred, regarding the code or other CFD issues, Johan Anderson at RISE Research Institutes of Sweden guided us through most of these problems and enabled us to move forward with the work. ParaView was used to visualize the simulation, and Excel was used to evaluate the temperature data from the FDS- and FireFOAM simulations. For the calculations in FDS and FireFOAM, a sensitivity analysis was performed to see which grid size presented best results in each program. A grid size of 5 cm, 10 cm, and 20 cm were applied in FDS, and in FireFOAM the grid dimensions were set to 5 cm and 10 cm. The results showed that 5 cm was the most appropriate grid size for both programs. It would have been more favorably to simulate with several different grid sizes, to further strengthen the grid analysis. Though, due to the time frame of the thesis, further simulations were not performed. Calculations were repeated for the same scenario only with a lower HRR (Heat release rate). An extensive sensitivity analysis was conducted for FDS in the form of two different simulations. One simulation where HRR was the same as the full-scale test but with twice the area of the burner. In the second simulation, the same area was used on the burner as the fullscale test, but with half the HRR. Results from the analytical solutions were easy to achieve; however, the model has some limitations regarding calculations within the flame region. The estimated gas temperature, using FDS, aligns well with the full-scale test. The temperatures analyzed from FireFOAM deviated in general through the flame region and reached unreasonable high temperatures close to the ceiling. Since the analytical solutions were based on different conditions compared to those applied in the full-scale test, it was expected that the results should deviate. However, McCaffrey plume equations can still be used to give an approximate picture of scenarios similar to that of the full-scale test, and the same applies to Eurocode solutions for localized fire temperatures. Analysis of the results shows that FDS can be used to simulate similar scenarios. FireFOAM simulates a gas temperature that is overestimated within the flame region. One of the reasons for this was due to the grid size since the sensitivity analysis III showed that a refined grid size resulted in more correct temperature value, the reason for not simulating with a more refined grid size was due to the restricted time frame of this thesis. FireFOAM is, at present, recommended for researchers who wish to use the code for specific purposes. Therefore, given the same premises, FireFOAM is not recommended for the standard fire safety analysis.
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Lau, Yip Hang. „Maximization of treatment capacity of a full-scale biological nitrogen removal plant through model simulation and full-scale stress test /“. View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?EVNG%202005%20LAU.
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Yang, Tong. „CFD and field testing of a naturally ventilated full-scale building“. Thesis, University of Nottingham, 2004. http://eprints.nottingham.ac.uk/10091/.
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Natural ventilation has the potential to provide good indoor air quality, thermal comfort for occupants, and can also save energy and reduce CO2 emissions. Computational fluid dynamics (CFD) offers detailed information about indoor flow patterns, air movement, temperature and local draught distribution in buildings, so it has unique advantages as an efficient and cost-effective tool for optimum design in a complex built environment. This thesis shows the use of CFD to simulate the coupled external and internal flow field around a 6m cubic building with two small openings. To study both wind driven and combined wind and buoyancy driven cross ventilation through a full-scale cubic structure, un-structured grid CFD and a steady envelope flow model were applied to calculate mean ventilation rates. To validate the CFD results, full-scale experiments were undertaken under various weather conditions in England. For wind driven ventilation RANS model predictions were proved reliable when wind directions were near normal to the ventilation openings, i.e. 0o~30o. However, when the fluctuating ventilation played a more dominant role than the mean flow (90o) RANS models were incapable of predicting the total ventilation rate. Improved results may be expected by applying more sophisticated turbulence models, such as LES, weighted quasi-steady approximations, or unsteady envelope flow models. In the thesis experience on the modelling of combined wind and thermal effects is outlined and feedback is provided to CFD code developers to enable further improvements for building ventilation studies. The full-scale field testing data from this study is valuable for comparison with wind tunnel results and validation of CFD applications.
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Dalley, Sam. „Wind tunnel measurements on a low rise building and comparison with full-scale“. Thesis, University of Surrey, 1993. http://epubs.surrey.ac.uk/886/.
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Costello, Kelly. „Full Scale Evaluation of Organic Soil Mixing“. Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6076.
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Soil mixing is a procedure that has proven to be effective for loose or soft compressible soils. The method stabilizes the soil in-place using specialized augers, tillers, or paddles that inject grout or dry cementitious powders as part of the mixing process. The Federal Highway Administration design manual for soil mixing helps to estimate the required amount of cementitious binder to produce a target design strength. However, it is biased towards inorganic soils and only mentions caution when confronting organic soils which usually come with a high water table, moisture content and void volume.
The Swedish Deep Stabilization Research Centre cited studies with highly organic soils in regards to soil mixing and suggested that organic soils may need to reach a ‘threshold’ of cement content before strength gain can occur. The University of South Florida also conducted a study on highly organic soils and was able to confirm this concept. USF also proposed a threshold selection curve based on the organic content. This thesis extends this concept to the bench scale testing of multiple full scale field studies.
This thesis will conclude with the presentation of new threshold curves based on the new data from the added field case studies. Given that there were variable binders and soil types used in the data analyzed, these threshold curves are dependent upon soil type and binder type, thus expanding upon the curve previously suggested.
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Walsh, J. Matthew. „Full-scale lateral load test of a 3x5 pile group in sand /“. Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd955.pdf.
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Walsh, James Matthew. „Full-Scale Lateral Load Test of a 3x5 Pile Group in Sand“. BYU ScholarsArchive, 2005. https://scholarsarchive.byu.edu/etd/605.
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Although it is well established that spacing of piles within a pile group influences the lateral load resistance of that group, additional research is needed to better understand trends for large pile groups (greater than three rows) and for groups in sand. A 15-pile group in a 3x5 configuration situated in sand was laterally loaded and data were collected to derive p-multipliers. A single pile separate from the 15-pile group was loaded for comparison. Results were compared to those of a similar test in clays. The load resisted by the single pile was greater than the average load resisted by each pile in the pile group. While the loads resisted by the first row of piles (i.e. the only row deflected away from all other rows of piles) were approximately equal to that resisted by the single pile, following rows resisted increasingly less load up through the fourth row. The fifth row consistently resisted more than the fourth row. The pile group in sand resisted much higher loads than did the pile group in clay. Maximum bending moments appeared largest in first row piles. For all deflection levels, first row moments seemed slightly smaller than those measured in the single pile. Maximum bending moments for the second through fifth rows appeared consistently lower than those of the first row at the same deflection. First row moments achieved in the group in sand appeared larger than those achieved in the group in clay at the same deflections, while bending moments normalized by associated loads appeared nearly equal regardless of soil type. Group effects became more influential at higher deflections, manifest by lower stiffness per pile. The single pile test was modeled using LPILE Plus, version 4.0. Soil parameters in LPILE were adjusted until a good match between measured and computed responses was obtained. This refined soil profile was then used to model the 15-pile group in GROUP, version 4.0. User-defined p-multipliers were selected to match GROUP calculated results with actual measured results. For the first loading cycle, p-multipliers were found to be 1.0, 0.5, 0.35, 0.3, and 0.4 for the first through fifth rows, respectively. For the tenth loading, p-multipliers were found to be 1.0, 0.6, 0.4, 0.37, and 0.4 for the first through fifth rows, respectively. Design curves suggested by Rollins et al. (2005) appear appropriate for Rows 1 and 2 while curves specified by AASHTO (2000) appear appropriate for subsequent rows.
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Hayden, Audra H. „Correlation between field and laboratory testing for a full-scale stormwater pond“. Tallahassee, Florida : Florida State University, 2010. http://etd.lib.fsu.edu/theses/available/etd-12062009-083125.
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Thesis (M.S.)--Florida State University, 2010.Advisor: Kamal Tawfiq, Florida State University, College of Engineering, Dept. of Civil and Environmental Engineering. Title and description from dissertation home page (viewed on July 14, 2010). Document formatted into pages; contains x, 99 pages. Includes bibliographical references (p. 96-98).
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Karikari-Boateng, Kwaku Ampea. „Accelerated testing of tidal turbine main bearing in a full scale nacelle test rig“. Thesis, University of Exeter, 2016. http://hdl.handle.net/10871/31210.
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Tidal Energy is one of the growing renewable energy technologies that is aimed at tackling global energy challenges. The Horizontal Axis Tidal Turbine (HATT) is an in-stream Tidal Energy Converter (TEC) which extracts kinetic energy from tidal flows. These tidal turbines face many reliability challenges due to their complexity, harsh operating environment and low accessibility. One of the component contributing significantly to the reliability of a TEC is the bearing supporting the rotating shaft within the nacelle. The reliability assessment of this component is essential during the design process and before their eventual deployments. This work is describes shaft bearing reliability assessment procedures. In recent years, the Offshore Renewable Energy (ORE) Catapult’s National Renewable Energy Centre has developed a dedicated multi axis test facility for full scale testing of tidal turbine nacelles and components (i.e. Nautilus). This work presents a methodology for testing tidal turbine shaft bearings in a representative manner in the full scale nacelle test rig, Nautilus. Two aspects are considered, namely the damage assessment and the damage replication in an accelerated manner. The damage assessment process considers the global loading on the shaft bearing and a Rigid Dynamics (RD) model has been applied to identify the local bearing loads. Local loads are converted to stress enabling the identification of stress-life relationship and bearing damage. The damage replication process is aimed to evaluate the 20 year damage and the Acceleration by Phase-shift (AbP) method has been developed to accelerate the cumulative damage. The AbP method enables the assessment of performance characteristics of shaft bearings in a laboratory environment, reducing failure rates, validate performance in a cost effective manner by reduced testing times. Within this work, novel processes for shaft bearing reliability assessments and demonstration are suggested and it concludes with the presentation of a recommended test plan for carrying out accelerated tests on a full scale bearing.
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Christensen, Dustin Shaun. „Full Scale Static Lateral Load Test of a 9 Pile Group in Sand“. Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1267.pdf.
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HARA, Sunao. „The examination of a spoken dialogue system construction for a large scale field test“. INTELLIGENT MEDIA INTEGRATION NAGOYA UNIVERSITY / COE, 2005. http://hdl.handle.net/2237/10399.
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Guillement, Claire. „Pile – Soil Interaction during Vibratory Sheet Pile Driving : a Full Scale Field Study“. Thesis, KTH, Jord- och bergmekanik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-136578.
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Urban construction sites require strict control of their environmental impact, which, for vibratory sheet pile driving, can include damage to nearby structures due to ground vibrations. However, the lack of knowledge concerning the generation of soil vibrations makes the prediction of ground vibration levels difficult. This MSc. thesis in particular, focuses on a crucial link in the vibration transfer chain: the sheet pile – soil interface, which is also one of the least documented. The aim of this thesis is first, to carry out a full-scale field test consisting in the monitoring of sheet pile and ground vibrations during sheet pile vibratory driving. And second, to analyze a selected portion of the collected data with focus on the sheet pile – soil vibration transfer. Both aspects of the thesis work aim, more generally, to contribute to the understanding of ground vibration generation under vibratory sheet pile driving. The full-scale field study was performed in Solna in May 2013. It consisted in the vibratory driving of seven sheet piles, out of which three were fitted with accelerometers. During the driving, ground vibrations were measured by accelerometers, the closest ones placed only 0.5 m from the sheet pile line. The design and installation of the soil instrumentation was innovative in as much as accelerometers were not only set on the ground surface but also at three different depths (~ 3 m, 5 m and 6 m). The analysis presented in this thesis is primarily a comparison between sheet pile vibrations and ground vibrations measured 0.5 m from the sheet pile line. The principal aspects considered in the comparison are: the influence of penetration through different soil layers, the sheet pile – soil vibration transfer efficiency, the frequency content of sheet pile and soil vibrations, and differences between toe- and shaft-generated vibrations. The main conclusions from this study are: Most of the vibration loss occurs in the near field: 90-99% of the sheet pile vibration magnitude was dispersed within 0.5 m from the driven sheet pile. Moreover, the sheet pile – soil vibration transfer efficiency was reduced for higher sheet pile acceleration levels and higher frequencies. The soil characteristics strongly influence the sheet pile vibration levels. A clear distinction could be made between "smooth" and "hard" driving, the latter being associated with an impact situation at the sheet pile toe. The focus of ground vibration studies should not only be the vertical vibrations. Indeed, the ground vibrations’ horizontal component was found to be of the same or even higher magnitude than the vertical component.
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Sutman, Melis. „Thermo-Mechanical Behavior of Energy Piles: Full-Scale Field Testing and Numerical Modeling“. Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/82438.
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Energy piles are deep foundation elements designed to utilize near-surface geothermal
energy, while at the same time serve as foundations for buildings. The use of energy piles for
geothermal heat exchange has been steadily increasing during the last decade, yet there are
still pending questions on their thermo-mechanical behavior. The change in temperature
along energy piles, resulting from their employment in heat exchange operations, causes axial
displacements, thermally induced axial stresses and changes in mobilized shaft resistance
which may have possible effects on their behavior. In order to investigate these effects, an
extensive field test program, including conventional pile load tests and application of
heating-cooling cycles was conducted on three energy piles during a period of six weeks.
Temperature changes were applied to the test piles with and without maintained mechanical
loads to investigate the effects of structural loads on energy piles. Moreover, the lengths of
the test piles were determined to represent different end-restraining conditions at the toe.
Various sensors were installed to monitor the strain and temperature changes along the test
piles. Axial stress and shaft resistance profiles inferred from the field test data along with the
driven conclusions are presented herein for all three test piles. It is inferred from the field test
results that changes in temperature results in thermally induced compressive or tensile axial
stresses along energy piles, the magnitude of which increases with higher restrictions such as
structural load on top or higher toe resistance. Moreover, lower change in shaft resistance is
observed with increasing restrictions along the energy piles. In addition to the design,
deployment, and execution of the field test, a thermo-mechanical cyclic numerical model was
developed as a part of this research. In this numerical model, load-transfer approach was
coupled with the Masing's Rule in order to simulate the two-way cyclic axial displacement of
energy piles during temperature changes. The numerical model was validated using the field
test results for cyclic thermal load and thermo-mechanical load applications. It is concluded
that the use of load-transfer approach coupled with the Masing's Rule is capable of
simulating the cyclic thermo-mechanical behavior of energy piles.Ph. D.
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Taylor, Amy Jean. „Full-scale-lateral-load test of a 1.2 m diameter drilled shaft in sand /“. Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1263.pdf.
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McCall, Amy Jean Taylor. „Full-Scale-Lateral-Load Test of a 1.2 m Diameter Drilled Shaft in Sand“. BYU ScholarsArchive, 2006. https://scholarsarchive.byu.edu/etd/403.
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The soil-structure interaction models associated with laterally loaded deep foundations have typically been based on load tests involving relatively small diameter foundations. The lateral soil resistance for larger diameter foundations has been assumed to increase linearly with diameter; however, few, if any load tests have been performed to confirm this relationship. To better understand the lateral resistance of large diameter deep foundations in sand, a series of full scale, cyclic, lateral load tests were performed on two 1.2 m diameter drilled shafts and a 0.324 m diameter steel pipe pile in sand. Although the tests involve two different foundation types, the upper 2.4 m of the profile, which provides the majority of the lateral resistance, consists of sand compacted around both foundation types. Therefore, these test results make it possible to evaluate the effect of foundation diameter on lateral soil resistance. The drilled shafts were first loaded in one direction by reacting against a fifteen-pile group. Subsequently a load test was performed in the opposite direction by reacting against a 9-pile group. The soil profile below the 2.4 m-thick layer of compacted sand consisted of interbedded layers of sand and fine-grained soil. For the drilled shaft load tests, pile head deflection and applied load were measured by string potentiometers and load cells, respectively. Tilt was also measured as a function of depth with an inclinometer which was then used to calculate deflection and bending moment as a function of depth. For the pipe pile, deflection and applied load were also measured; however, bending moment was computed based on strain gauges readings along the length of the pile. The lateral response of the drilled shafts and pipe pile were modeled using the computer programs LPILE (Reese et al., 2000), SWM6.0 (Ashour et al., 2002), and FB-MultiPier Version 4.06 (Hoit et al., 2000). Comparisons were made between the measured and computed load-deflection curves as well as bending moment versus depth curves. Soil parameters in the computer programs were iteratively adjusted until a good match between measured and computed response of the 0.324 m pipe pile was obtained. This refined soil profile was then used to model the drilled shaft response. User-defined p-multipliers were selected to match the measured results with the calculated results. On average very good agreement was obtained between measured and computed response without resorting to p-multipliers greater than 1.0. These results suggest that a linear increase in lateral resistance with foundation diameter is appropriate. LPILE typically produced the best agreement with measured response although the other programs usually gave reasonable results as well. Cyclic loading generally reduced the lateral resistance of the drilled shafts and pile foundation by about 20%.
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Corazao, Gallegos Juan Carlos. „The design, construction, instrumentation and initial response of a field-scale waste rock test pile“. Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/31646.
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The geochemical and hydrological behavior of waste rock systems is usually predicted by conducting laboratory scale tests such as humidity cells and small-scale barrel tests. While these test procedures for the prediction of geochemical behavior are well developed and widely adopted in practice, little is known if the results obtained from these small scale tests can be used to describe and predict the full-scale behavior of waste rock impoundments under natural field conditions. Direct observations and measurements of water movement through waste rock dumps are necessary to improve the understanding of the hydrology of the dump and its influence on the geochemistry of full-scale waste rock dumps. These observations of oxygen and water movement are possible through the implementation of field-scale experiments. Some field-scale experiments have been developed in the last few decades; all of them focus primarily on studying waste rock geochemistry and hydrology in acid production environments. However, some ore bodies are hosted in rock with high neutralization capacity such as carbonates, generating alkaline/neutral drainage from the waste rock dumps. This type of drainage can also produce adverse effects on the environment. The alkaline/neutral drainage from waste rock dumps can limit the dissolution and mobility of some metals although other environmentally hazardous elements are not strongly attenuated at high pH. This thesis is part of an extensive research program currently undertaken by the University of British Columbia in Vancouver, Canada in collaboration with Teck Cominco Limited, the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Antamina mine in Peru to investigate waste rock hydrology and geochemistry in a neutral drainage environment. The field experimentation includes five field-scale waste rock test piles, a number of barrel-sized field cells and a cover study. The scope of this research involved the design, construction and instrumentation of a field-scale waste rock test pile constructed at the Antamina mine, which is hosted in rock with high ii neutralization capacity. The experimental data was used to analyze the initial hydrological and geochemical response of the constructed pile. The general conclusions are that: the test pile construction sequence and the meteorological conditions at the site during the construction and subsequent operation of the pile had a significant influence on the initial hydrological response of the test pile; the infiltration and drainage conditions in the test pile reached a semi-steady state in relatively short period of time; the effect of material segregation, heterogeneity and the presence of preferential flow paths appear to be evident; and, that the levels of electrical conductivity measured and the sulfates released along with concentrations of metals such as Cu and Zn suggests that oxidation is taking place within the pile.Applied Science, Faculty of
Mining Engineering, Keevil Institute of
Graduate
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Kevan, Luke Ian. „Full-Scale Testing of Blast-Induced Liquefaction Downdrag on Driven Piles in Sand“. BYU ScholarsArchive, 2017. https://scholarsarchive.byu.edu/etd/6966.
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Deep foundations such as driven piles are often used to bypass liquefiable layers of soil and bear on more competent strata. When liquefaction occurs, the skin friction around the deep foundation goes to zero in the liquefiable layer. As the pore pressures dissipate, the soil settles. As the soil settles, negative skin friction develops owing to the downward movement of the soil surrounding the pile. To investigate the magnitude of the skin friction along the shaft three driven piles, an H-pile, a closed end pipe pile, and a concrete square pile, were instrumented and used to measure soil induced load at a site near Turrell, Arkansas following blast-induced liquefaction. Measurements were made of the load in the pile, the settlement of the ground and the settlement of piles in each case. Estimates of side friction and end-bearing resistance were obtained from Pile Driving Analyzer (PDA) measurements during driving and embedded O-cell type testing. The H-pile was driven to a depth of 94 feet, the pipe pile 74 feet, and the concrete square pile 72 feet below the ground surface to investigate the influence of pile depth in response to liquefaction. All three piles penetrated the liquefied layer and tipped out in denser sand. The soil surrounding the piles settled 2.5 inches for the H-pile, 2.8 inches for the pipe pile and 3.3 inches for the concrete square pile. The piles themselves settled 0.28 inches for the H-pile, 0.32 inches for the pipe pile, and 0.28 inches for the concrete square pile. During reconsolidation, the skin friction of the liquefied layer was 43% for the H-pile, 41% for the pipe pile, and 49% for the concrete square pile. Due to the magnitude of load felt in the piles from these tests the assumption of 50% skin friction developing in the liquefied zone is reasonable. Reduced side friction in the liquefied zone led to full mobilization of skin friction in the non-liquefied soil, and partial mobilization of end bearing capacity. The neutral plane, defined as the depth where the settlement of the soil equals the settlement of the pile, was outside of the liquefied zone in each scenario. The neutral plane method that uses mobilized end bearing measured during blasting to calculate settlement of the pile post liquefaction proved to be accurate for these three piles.
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Otaki, Takeshi. „SIZE EFFECTS IN SHEAR FAILURE OF REINFORCED CONCRETE BRIDGE COLUMNS - FULL SCALE TEST AND ANALYTICAL EVALUATION“. Kyoto University, 2001. http://hdl.handle.net/2433/150668.
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Constantinides, Annie. „The validity, reliability and objectivity of a field test of squash fitness /“. Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63340.
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Kirkov, Kirko Dimitar. „Tearing resistance for fillet welds in ships exposed to grounding : a full scale test & cost implications“. Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/11671.
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Kjellstrand, Robert. „Hydraulic Behaviour in an Activated Sludge Tank : From Tracer Test through Hydraulic Modelling to Full-Scale Implementation“. Licentiate thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-3390.
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Hydraulic behaviour in a large denitrifying activated sludge tank, located at the Rya Wastewater treatment plant (WWTP) in Göteborg Sweden, was investigated and optimized by using fullscale tracer test and hydraulic modelling. The Rya WWTP is a high loaded plant with a small footprint. Expansion of the site is limited due to several restrictions. An efficient use of already existing facilities is therefore of great importance in order to meet the demands of decreased effluent limits, set by authorities. The presence of a short circuiting stream was identified with full-scale tracer tests and the hydraulic situation was successfully quantified using the Martin model, a compartment model based on curve fitting to the residence time distribution curve (RTD-curve) from the full-scale tracer test. Computational fluid dynamics (CFD) 3D modelling was used for virtual prototyping of different corrective measures near the inlet to break the previously identified short circuiting stream. From an operational point of view, inlet baffles were chosen as the preferable alternative. After implementation, improved tank hydraulics, were verified with another full-scale tracer test. At a normal flow (3.6 m3/s), the space time in the tank was found to be 16 minutes. In the original tank 30 % of the water had a residence time of less than 8 minutes, 49 % of the water had a residence time between 8 and 24 minutes and 21 % of the water had a residence time of more than 24 minutes. After implementation of corrective measures, the tank with baffles had 6 % of the water with a residence time of less than 8 minutes. 77 % of the water had a residence time between 8 and 24 minutes and 17 % of the water had a residence time of more than 24 minutes. Also, the mixing characteristics in the tank achieved a more plug-flow like character. Full-scale tracer tests are very informative when investigating hydraulic situations in activated sludge tanks. Mathematical modelling using black box approach can help to quantifying the hydraulics in a tank. For example can use of the Martin model help to quantify short circuiting streams and dead volumes. CFD modelling is a useful and informative tool for analyzing problematic hydraulics at wastewater treatment plants and for the design of theoretical corrective measures. Being a useful tool for virtual prototyping, this type of modelling also deserves to have a more central role when designing large reactors and other hydraulic systems.I. Short Circuiting in a Denitryfying Activated Sludge Tank.
R. Kjellstrand, A. Mattsson, C. Niklasson and M.J. Taherzadeh.
Water Science & Technology, Vol. 52, No. 10-11, pp 79-87, IWA Publishing 2005. II. Improved Hydraulic Behaviour in a Denitrifying Activated Sludge Tank.
R. Kjellstrand, A. Mattsson.
Submitted
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Hollenbaugh, Joseph Erick. „Full-Scale Testing of Blast-Induced Liquefaction Downdrag on Auger-Cast Piles in Sand“. BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/5494.
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Deep foundations like auger-cast piles and drilled shafts frequently extend through liquefiable sand layers and bear on non-liquefiable layers at depth. When liquefaction occurs, the skin friction on the shaft decreases to zero, and then increases again as the pore water pressure dissipates and the layer begins to settle, or compact. As the effective stress increases and the liquefiable layer settles, along with the overlaying layers, negative skin from the soil acts on the shaft. To investigate the loss of skin friction and the development of negative skin friction, soil-induced load was measured in three instrumented, full-scale auger-cast piles after blast-induced liquefaction at a site near Christchurch, New Zealand. The test piles were installed to depths of 8.5 m, 12 m, and 14 m to investigate the influence of pile depth on response to liquefaction. The 8.5 m pile terminated within the liquefied layer while the 12 m and 14 m piles penetrated the liquefied sand and were supported on denser sands. Following the first blast, where no load was applied to the piles, liquefaction developed throughout a 9-m thick layer. As the liquefied sand reconsolidated, the sand settled about 30 mm (0.3% volumetric strain) while pile settlements were limited to a range of 14 to 21 mm (0.54 to 0.84 in). Because the ground settled relative to the piles, negative skin friction developed with a magnitude equal to about 50% of the positive skin friction measured in a static pile load test. Following the second blast, where significant load was applied to the piles, liquefaction developed throughout a 6-m thick layer. During reconsolidation, the liquefied sand settled a maximum of 80 mm (1.1% volumetric strain) while pile settlements ranged from 71 to 104 mm (2.8 to 4.1 in). The reduced side friction in the liquefied sand led to full mobilization of side friction and end-bearing resistance for all test piles below the liquefied layer and significant pile settlement. Because the piles generally settled relative to the surrounding ground, positive skin friction developed as the liquefied sand reconsolidated. Once again, skin friction during reconsolidation of the liquefied sand was equal to about 50% of the positive skin friction obtained from a static load test before liquefaction.
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Eastman, Mark 1982. „Field-scale nutrient transport monitoring and modeling of subsurface and naturally drained agricultural lands“. Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=112620.
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Eutrophication impacts the quality of many surface waters worldwide. Algal blooms threaten lake water quality and in order to control their growth, understanding of nutrient transport at the field-scale is essential. In order to accomplish this, a combination of field monitoring and computer modeling with the SWAT model was undertaken.Four sites located in the Pike River watershed of southern Quebec were instrumented to monitor nutrient losses from both clay loam and sandy loam soils under both subsurface and naturally drained conditions. Results illustrate how the presence of subsurface drainage influences phosphorus loss depending on soil texture and structure. Total phosphorus loss from the clay loam subsurface drained site was 4.0 kg ha-1, 55% greater than the naturally drained clay loam site. Total phosphorus loss from the sandy loam subsurface drained site was 1.2 kg ha-1, 14% less than the naturally drained sandy loam site. Total phosphorus losses from the subsurface drainage systems in the clay loam field and the sandy loam field were 2.3 and 0.4 kg ha-1, respectively. Particulate phosphorus was the dominant (78%) form of phosphorus loss from the subsurface drainage system at the clay loam site. This indicates that bypass flow through the soil profile in the clay loam field led to excessive total phosphorus loss.
SWAT, a watershed-scale model was calibrated with over 6 site years of data, in an attempt to simulate hydrology and pollutant transport at the field-scale. After calibration, the monthly Nash-Sutcliffe Efficiency varied from 0.09 to 0.74 for total drainage; 0.04 to 0.71 for sediment loading; 0.29 to 0.48 for nitrate loads and 0.28 to 0.64 for total phosphorus loads. Overall, SWAT has shown that it has the ability to simulate long-term sediment and nutrient transport at the field-scale. This makes SWAT a valuable tool for the development and evaluation of various beneficial management practices which control sediment and nutrient loss from agricultural fields.
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Bratlie, Andreas, und Christian Bergstrøm Hillestad. „Impact on Duplex Steel Pipes with Precipitated Sigma-phase : Modeling a Full-scale Impact Test on Pipe Fittings“. Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for konstruksjonsteknikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18722.
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Duplex stainless steel (DSS) is a common material in offshore pipe fittings. A manufacturing defect has altered the behavior of the components through an erroneous heat treatment, which has led to precipitation of 𝜎-phase. A report showing a strong correlation between precipitated 𝜎-phase and the reduction in impact toughness, initiated a great interest in the offshore industry for further studies of the effect of precipitated 𝜎-phase in DSS pipe fittings. In this thesis a numerical approach to simulate the behavior of duplex stainless steel with precipitated 𝜎-phase has been performed. The simulations have been done using the Gurson material model, which is implemented in the user defined material model in the SIMLab Metal Model. In addition the material model has been combined with a brittle fracture criterion. The results deviate from the observations done in the laboratory. The reasons for the deviations were found to be quite complex, but effects from mesh sensitivity and incorrect material optimization was found. The influence of the Gurson model is limited for the specimens acting in a brittle manner. It is therefore considered unnecessary to apply this material model for these problems.
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Dupray, Sebastien. „Integrity of rock blocks for armouring of hydraulic works : towards full-scale test to predict mass distribution changes“. Thesis, Imperial College London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.420579.
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Derbyshire, Adrian. „Development of a full scale crash test procedure and evaluation of an energy absorbing pole on an embankment“. Thesis, Queensland University of Technology, 2001. https://eprints.qut.edu.au/36143/1/36143_Derbyshire_2001.pdf.
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Based on the massive social cost of road crashes to the Australian community it is necessary to improve the safety of Australia's road network by undertaking focused
road safety initiatives. Single vehicle run-off-road incidents with lighting poles contribute to a large proportion of road fatalities and are therefore the focus of this research. Due to poor in-service performance of slip base poles in unlevel roadside environments it is necessary to conduct full scale testing that represents actual impact conditions. Energy absorbing poles have considerable performance advantages and
thus were selected as the test article for the full scale crash test contained in this research. To conduct the test it was necessary to develop a full scale test procedure based on international best practice. The procedure adopted to guide the test vehicle utilises a
guide cable and steering attachment with a tow vehicle capable of accelerating a mass of up to 2 tonnes to 100 km/h within four kilometres per hour of the design
impact speed.The test arrangement simulates an 820 kilogram vehicle leaving the carriageway at
an angle of twenty degrees, and over a verge at 70 km/h. A test height of 600mm above the normal impact height that would occur on a level grade was selected based
on an investigation of typical roadside topography.
Based on preliminary trials and the results of the pole test, the procedure was considered acceptable and recommended for use in future testing applications. The
performance of the energy absorbing pole was satisfactory, according to the evaluation criteria contained in NCHRP Report 350. Detachment of the luminaire and outreach arm detracted from the overall performance of the pole.
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Draier, Benny. „Test vector generation and compaction for easily testable PLAs“. Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63970.
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Cummings, W. Mark. „Smoke Movement Analysis (Smoke Transport Within a Corridor)“. Digital WPI, 2004. https://digitalcommons.wpi.edu/etd-theses/1088.
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"A series of full-scale fire tests were performed, using a fire compartment and an adjoining long (30+ m) corridor, as part of an effort to quantify the dynamics associated with smoke transport within a corridor. The tests were performed at the U.S. Coast Guard Research and Development Center’s Fire and Safety Test Detachment in Mobile, Alabama on board the Test Vessel Mayo Lykes. The resulting empirical data was analyzed in an effort to develop a method that could be used to estimate the movement of smoke within a corridor. The objective is to potentially incorporate this method into a smoke movement analysis “tool†that could, in turn, be used in conjunction with a fire safety analysis methodology previously developed by the U.S. Coast Guard; the Ship fire Safety Engineering Methodology (SFSEM). The goal is to develop a smoke movement analysis “module†that can be utilized in conjunction with the SFSEM when conducting an overall fire safety analysis of a ship. Of particular interest is the speed at which the smoke propagates along the length of the corridor. The focus of a smoke movement module would be life safety. A conservative assumption is made that if smoke is present in sufficient quantities to fill a corridor, then the corridor is to be considered untenable and not available as a means of egress. No attempt is made to address toxicity or density issues associated with smoke. This analysis developed correlations for the corridor smoke velocity, both as a function of the heat release rate of the associated fire and the upper layer temperatures within the fire compartment. Problems associated with the data collection and the narrow range of fire sizes used had a detrimental impact on the confidence level in the correlation based on heat release rate. The data do appear to confirm the results of previous efforts that indicated a weak relationship between the heat release rate and smoke velocity, on the order of the one-third to one-fourth power. The temperature data tended to be less problematic. This correlation shows promise for potential use with both the SFSEM and other existing computer models/routines. However, unlike previous studies of this relationship, the results of these data suggest that the velocity-temperature relationship is linear and not a square-root function. The test data were compared to predictive results using the CORRIDOR routine within FPETOOL. In general, the CORRIDOR results provided a reasonable good correlation to the tests data. Both the wave depth and temperature loss within the wave, as a function of distance, were consistently over-predicted. The velocity results were mixed, but were generally within 20 percent of the test data. The results of this study show promise, with respect to developing a correlation that can be used a method for predicting smoke movement in a corridor. However, due to the questionable nature of some of the data estimates, coupled with both a lack of sufficient number of tests and a limited range of fire sizes used, additional test data will be required to further validate the accuracy and refine the correlation(s) suggested by this work."
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Nuttayasakul, Nuthaporn. „Experimental and Analytical Studies of the Behavior of Cold-Formed Steel Roof Truss Elements“. Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/29765.
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Cold-formed steel roof truss systems that use complex stiffener patterns in existing hat shape members for both top and bottom chord elements are a growing trend in the North American steel framing industry. When designing cold-formed steel sections, a structural engineer typically tries to improve the local buckling behavior of the cold-formed steel elements. The complex hat shape has proved to limit the negative influence of local buckling, however, distortional buckling can be the controlling mode of failure in the design of chord members with intermediate unbraced lengths. The chord member may be subjected to both bending and compression because of the continuity of the top and bottom chords. These members are not typically braced between panel points in a truss.
Current 2001 North American Specifications (NAS 2001) do not provide an explicit check for distortional buckling. This dissertation focuses on the behavior of complex hat shape members commonly used for both the top and bottom chord elements of a cold-formed steel truss. The results of flexural tests of complex hat shape members are described. In addition, stub column tests of nested C-sections used as web members and full scale cold-formed steel roof truss tests are reported.
Numerical analyses using finite strip and finite element procedures were developed for the complex hat shape chord member in bending to compare with experimental results. Both elastic buckling and inelastic postbuckling finite element analyses were performed. A parametric study was also conducted to investigate the factors that affect the ultimate strength behavior of a particular complex hat shape.
The experimental results and numerical analyses confirmed that modifications to the 2001 North American Specification are necessary to better predict the flexural strength of complex hat shape members, especially those members subjected to distortional buckling. Either finite strip or finite element analysis can be used to better predict the flexural strength of complex hat shape members. Better understanding of the flexural behavior of these complex hat shapes is necessary to obtain efficient, safe design of a truss system. The results of these analyses will be presented in the dissertation.Ph. D.
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Haggerty, Daniel. „A Comparison of Predicted Brace Loads in Temporary Retaining Structures and Observed Brace Loads in Two Full Scale Test Sections“. ScholarWorks@UNO, 2003. http://scholarworks.uno.edu/td/51.
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This thesis presents analyses of the results of a geotechnical instrumentation program performed by Eustis Engineering Company for the U.S. Army Corps of Engineers (USACE) during the construction of two covered canals in New Orleans, Louisiana. At each site, a cast-in-place concrete culvert was constructed within a sheeted and braced excavation. Information provided by Eustis Engineering Company to the USACE is presented describing the existing soil conditions, the construction schedule, the geotechnical testing apparatus and instrumentation, and the data produced from the geotechnical instrumentation program. In this thesis, several theoretical approaches available for estimating the strut loads in braced excavations were examined and used to predict the strut loads at the two construction sites. These theoretical approaches included Coulomb pressures diagrams, Terzaghi pressure diagrams, and soil-structure interaction. The results of the theoretical strut load prediction methods are presented and compared with the results of the geotechnical instrumentation program data.
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Wang, Shujiao. „Exploring the washback of a large-scale high-stakes Chinese test, the Hanyu Shuiping Kaoshi, on learner factors“. Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=119765.
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Washback research has tended to focus on whether washback exists and whether there is intended washback brought about by examinations in English as a second/foreign language (ESL/EFL contexts). This study, on the other hand, investigated how learner factors, such as learning strategies and beliefs, related to the washback of a large-scale high-stakes Chinese second language proficiency test, the Hanyu Shuiping Kaoshi (HSK). Using a mixed-methods research (MMR) approach, quantitative data were collected from Chinese as a second/foreign/heritage language (CSL) learner survey responses (n = 60) and qualitative data were elicited from 8 interviews and HSK related documents. Findings revealed that, an increasing number of people wanted to learn Chinese and take the HSK because they were interested not only in the Chinese language and culture, but also hoped to study, work or travel in China. They felt that becoming HSK-certified, helped them feel more motivated to learn Chinese and increased job opportunities. Thus, there were significant washback effects of the HSK on learning Chinese. Similar to previous research on washback, however, this study showed that the HSK had positive impact on some learners but negative effects on others. The finding showed statistically significant differences between regular Chinese learning (e.g., CSL courses, distance learning, or self-learning) and HSK test-specific learning among the four skills - speaking, listening, reading and writing. Significant predictors for the change in learning strategies between regular and test-specific learning were nationality, language proficiency, HSK performance and motivation. Finally, although it is claimed that the validity and reliability of the HSK content are high, this study points to some aspects that could be improved, such as including more subjective question forms and emphasizing the output (speaking and writing) measurements. This study has implications for HSK test developers, CSL teachers and CSL learners.Les recherches sur le washback, qu'on définit comme l'impact des examens déterminants sur l'enseignement et l'apprentissage, tentent de se questionner sur l'existence du washback en général ainsi que sa présence prévue par des épreuves d'anglais comme langue seconde ou étrangère. Cependant, cette étude s'est plutôt penchée sur la manière dont le profil de l'apprenant, soit ses stratégies d'apprentissage ainsi que ses croyances, influe sur le washback (l'effet en retour) d'une épreuve rigoureuse de langue chinoise à grande échelle appelée le Hanyu Shuiping Kaoshi (HSK). À l'aide d'une approche de méthodes mixtes de recherche, nous avons recensé des données quantitatives issues d'un sondage auprès des apprenants du chinois comme langue seconde/étrangère/maternelle. Pour ce qui est des données qualitatives, elles ont été tirées de huit entrevues et de plusieurs documents faisant référence au HSK. Les résultats ont révélé que le nombre d'apprenants du chinois ne cesse d'accroître et qu'ils ont choisi de faire le HSK parce qu'ils avaient l'intention d'étudier, de travailler ou de voyager en Chine, en plus de leur vif intérêt pour la langue et la culture chinoises. Ces étudiants se sont rendu compte que le fait de réussir le HSK les a aidés à gagner davantage de motivation à apprendre le chinois et à élargir leur champ de débouchés. Ainsi, l'impact du HSK s'avérait significatif sur l'apprentissage de la langue chinoise. Bien que cette étude soit analogue à des recherches antérieures sur le washback, elle a démontré que l'impact du HSK s'avérait positif chez certains apprenants, mais négatif chez d'autres. D'un point de vue statistique, les conclusions de la présente recherche ont souligné des différences significatives entre les cours réguliers du chinois et ceux basés sur le HSK en ce qui concerne quatre compétences : l'oral, l'écoute, la lecture et l'écriture. Parmi les principaux facteurs jouant un rôle sur la variété des stratégies d'apprentissage, on retrouvait la nationalité, la maîtrise de la langue, la performance du HSK et la motivation. Finalement, même si la validité et la fiabilité du contenu du HSK apparaissent élevées, cette étude révèle certains aspects qui pourraient être améliorés, soit l'ajout de structures interrogatives subjectives et l'emphase sur les outils d'évaluation du sortant, c'est-à-dire l'expression orale et l'écriture. Cette recherche constitue donc une référence incontournable pour les concepteurs du HSK, pour les enseignants et pour les apprenants du chinois langue seconde.
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Klinck, Amanda. „An Experimental Investigation of the Fire Characteristics of the University of Waterloo Burn House Structure“. Thesis, University of Waterloo, 2006. http://hdl.handle.net/10012/774.
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This thesis reports on the procedure, results and analysis of four full scale fire tests that were performed at the University of Waterloo's Live Fire Research Facility. The purpose of these tests was to investigate the thermal characteristics of one room of the Burn House structure. Comparisons were made of Burn House experimental data to previous residential fire studies undertaken by researchers from the University of Waterloo. This analysis showed similarities in growth rate characteristics, illustrating that fire behaviour in the Burn House is typical of residential structure fire behaviour. The Burn House experimental data was also compared to predictions from a fire model, CFAST. Recommendations were made for future work in relation to further investigation of the fire characteristics of the Burn House.
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ORLANDO, ANDREA. „Full-scale monitoring of the wind-induced response of vertical slender structures, with fixed and rotating masses“. Doctoral thesis, Università degli studi di Genova, 2021. http://hdl.handle.net/11567/1049839.
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Nowadays, structural monitoring is gaining more and more attention in the field of wind engineering. On the wake of these developments, the thesis develops and applies a comprehensive structural monitoring procedure tailored for the validation and investigation in full-scale of the wind-induced response of vertical slender structures, with fixed and rotating masses. All the main aspects of the monitoring practice are discussed, regarding the number, location and type of the sensors, the acquisition and the transmission of the full-scale data, as well as the management of the experimental database by following an encoded scheme. In addition, the thesis highlights a number of issues typical of the monitoring activity that are not addressed in literature, providing inspiration to solve them. The defined procedure finds application in two monitoring campaigns launched by the Wind Engineering group at the University of Genoa: one slender structure with fixed masses (a light tower) and one slender structure with rotating masses (a small vertical axis wind turbine). As regards the light tower, a reference calculation model of the wind-induced response of poles and towers is selected from literature and is validated in full-scale. The input parameters needed for the application of the model are identified from experimental surveys, intersecting wind tunnel tests and dynamic identification techniques. The results highlight the goodness of the selected model and the large uncertainties associated to the input parameters. As regards the wind turbine, the full-scale data are used to investigate the contribution of the rotating parts to the dynamic behavior. In addition, the fatigue damage of the supporting tower is calculated under stationary and non-stationary excitation due to wind, turbine rotation, emergency stop and start. The results highlight the importance of the detail modeling, the fundamental role played by the non-stationary conditions and the errors committed when using conventional models of the load.
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Bégin, Mathieu. „Are quantitative genetic constraints to morphological evolution important on an evolutionary time scale? an empirical investigation in field crickets“. Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=84471.
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The evolutionary importance of genetic constraints has always been recognized by biologists, but very little data is available to quantitatively assess the role of constraints in shaping the biology of organisms. The field of quantitative genetics provides the tools necessary to study evolutionary constraints, mainly through the estimation of the matrix of additive genetic variance and covariance (the G matrix). The main goals of this Ph.D. dissertation were to study the persistence of constraints across environments and across species, to explore the consequences of constraints on species divergence, and to try to understand some morphological and life history characteristics of field crickets in light of genetic variation. Populations of seven wing-dimorphic cricket species from the genera Gryllus and Teleogryllus were sampled from the wild and reared in the laboratory. Using multiple statistical approaches to the comparison of G matrices, results revealed little variation in G matrices across species. Moreover, the relatively small effect of rearing environment and of the two wing morphologies on G were shown to be of the same magnitude as variation between species, therefore confirming the general constancy of genetic constraints through evolutionary time scales. Mean trait values, selection regimes and phylogenetic distances were all shown not to be predictors of G matrix variation. In agreement with the constraint hypothesis of quantitative genetic theory, morphological divergence between species was shown to be predictable from a reconstructed ancestral G matrix. In addition, information on genetic variation was used to explain various patterns relating to size, ovipositor length, wing morphology and diapause occurrence in field crickets. Overall, we suggest that genetic constraints, as described by quantitative genetics, have played a major role in shaping the observed biological diversity of field cricket species, a conclusion tha
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Rucker, Paul D. „A reliability comparison of recessed-gate and self-aligned gate small signal GaAs MESFETS utilizing an accelerated life test set designed for large scale automated testing“. Thesis, Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/71231.
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A large scale automated test set was designed and built to address the varied accelerated life test requirements of the GaAs industry. GaAs low-noise/small-signal MESFETs with 1 x 300 micron gate peripheries and 3 different gate structures were subjected to a 1000 hour high temperature storage test:
1) to compare the reliability performance and manufacturability of
a) recessed-gate MESFETs with TiPdAu gates
b) realigned self-aligned gate (RSAG) MESFETs with TiWNx Schottky and TiPdAu overlay
c) planarized self-aligned gate (PSAG) MESFETs with TiWNx Schottky and TiPdAu overlay.
2) to study the changes in Idss, Rg, Ro, gm, and Vp over time and their effects upon MAG (Maximum Available Gain).
3) to study failure criteria and their applicability toward accurate life predictions.
The recessed-gate devices suffered from Au/GaAs channel interdiffusion resulting in substantial dc parameter degradation above 225°C with an activation energy of 1.7 eV. Although the most widely used device structure in the GaAs industry, its process is not conducive to parameter uniformity.
The realigned self-aligned gate (RSAG) devices are an initial attempt at the fabrication of a self-aligned gate analog MESFET. They were found to exhibit excellent electrical characteristics, but their reliability performance was unpredictable due to the critical nature of the .5 micron TiPdAu gate overlay realignment to a 1 micron TiWNx Schottky.
Planarized self-aligned gate (PSAG) devices were found to be readily manufacturable and to exhibit excellent reliability.
The use of a decrease in MAG was found to be a more meaningful failure criterion than a 20% change in Idss, which is employed extensively in the literature.Master of Science
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Andersen, Rikke Granum. „In situ characterization and quantification of phytoremediation removal mechanisms for naphthalene at a creosote-contaminated site“. Diss., Virginia Tech, 2006. http://hdl.handle.net/10919/26408.
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Rikke Granum Andersen
In situ characterization and quantification of phytoremediation removal mechanisms for naphthalene at a creosote-contaminated site
Phytoremediation is an attractive remediation technology due to its relative low cost and maintenance requirement. Acceptance of phytoremediation requires that the contaminant removal mechanisms are characterized and demonstrated in the field. Quantification of contributions from each mechanism to the overall remediation rate is crucial for optimization of phytoremediation systems, risk management and prediction of the total remediation time. The objective of this research was to characterize and quantify removal mechanisms for naphthalene at a creosote-contaminated site with poplar trees in Oneida, Tennessee. Groundwater monitoring for seven years in the surficial aquifer at this site demonstrated a reduction in polycyclic aromatic hydrocarbons (PAHs) with selective removal of naphthalene and three-ring compounds. Naphthalene mass loss mechanisms investigated at this site are biodegradation in the saturated zone, volatilization and biodegradation in the vadose zone and phytovolatilization. This is probably the most comprehensive field study of PAH phytoremediation mechanisms conducted to date. The significance of this research is to contribute to predictions of remediation time and end result for phytoremediation of PAHs. The understanding of in situ factors controlling each mechanism can facilitate future optimization of phytoremediation systems as well as improve risk assessment and monitoring strategies.
Biodegradation rates were determined for different conditions at this site with in situ respiration tests, laboratory soil microcosms and laboratory soil columns. The combined remediation mechanisms of volatilization and biodegradation in the vadose zone were investigated in the field and in laboratory columns. Field measurements show that lower groundwater elevations in the summer and early fall lead to elevated groundwater concentrations of naphthalene and increased volatilization. The increase in the fraction of the porespace occupied by gas (gas saturation) in the unsaturated zone during the summer and fall further enhances the volatilization by increasing effective diffusion rates. Water consumption and interception by the phytoremediation system are believed to enhance mass transfer to the vadose zone. Column experiments and field measurements show that more than 90% of the naphthalene vapors are biodegraded within 5-10 cm above the groundwater table. The data indicate that biodegradation increases the overall volatilization flux out of the source by 10-300 times, when the source is exposed directly to the gas phase. In situ the naphthalene is generally dissolved from the source into the groundwater and then volatilezed from the groundwater to the gas phase. Under these conditions biodegradation in the vadose zone will still indirectly have an enhancing effect on the flux out of the source. This is the result of removal naphthalene from the soil gas by biodegrdation driving removal from the groundwater by volatilization, which in turn drives dissolution form the source into the groundwater.
Phytovolatilization was quantified in flux chambers mounted on trees and calculated from transpiration rates. A laboratory uptake study and analysis of tree cores from the site provided supplementary evidence for naphthalene uptake by poplar trees. Phytovolatilization was detected throughout the year and was highest in the summer and fall when the groundwater concentrations were highest and transpiration was active.
The role of biodegradation relative to physical removal mechanisms was compared for a year, for winter and summer conditions and with and without the impact of phytoremediation. Biodegradation of naphthalene in the saturated zone dominates by orders of magnitude over the removal by volatilization and phytovolatilization of naphthalene at this site. The removal of the total residual naphthalene mass was estimated to require up to 100 years with phytoremediation, but more than twice as long without phytoremediation. The estimated removal of naphthalene was three times larger in the summer than in the winter due to slower biodegradation in the saturated zone and smaller rates of volatilization to the vadose zone in the winter. The research shows that phytoremediation enhances the overall naphthalene removal, mainly by stimulating faster biodegradation in the rhizosphere and promoting mass transfer of naphthalene to the vadose zone followed by rapid vadose zone biodegradation. In the future, phytoremediation research focusing on the capillary zone is desirable.Ph. D.
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Saghebfar, Milad. „Performance of geotextile-reinforced bases for paved roads“. Diss., Kansas State University, 2014. http://hdl.handle.net/2097/18278.
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Doctor of PhilosophyDepartment of Civil Engineering
Mustaque Hossain
Geotextiles have been widely promoted for pavement structure over the past 30 years. However, there is a lack of well-instrumented, full-scale experiments to investigate the effect of geotextile reinforcement on the pavement design. In this study, full–scale accelerated tests were conducted on eight lanes of pavement test sections. Six out of these eight sections had granular bases reinforced with different types of woven geotextiles. The reinforced base sections and the control sections (with unreinforced base) were paved with Superpave hot-mix asphalt. Base and subgrade materials were the same for all sections while the test sections had different asphalt and base layer thicknesses. Each section was instrumented with two pressure cells on top of the subgrade, six strain gages on the geotextile body, six H-bar strain gages at the bottom of the asphalt layer, two thermocouples and one Time Domain Reflectometer (TDR) sensor. The sections were loaded to 250,000 to 500,000 repetitions of an 80-kN single axle load of the accelerated pavement testing machine. The mechanistic response of each section was monitored and analyzed at selected number of wheel passes. Results indicate that properly selected and designed geotextile-reinforced bases improve pavement performance in term of rutting and reduced pressure at the top of the subgrade. Finite element (FE) models were developed and verified using results from the full-scale accelerated pavement tests. The calibrated model was used to investigate the effects of geotextile properties on the pavement responses. FE analysis shows that benefits of reinforcement are more evident when stiffer geotextile is used.
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Snyder, Jeffrey L. „Full-Scale Lateral-Load Tests of a 3x5 Pile Group in Soft Clays and Silts“. Diss., CLICK HERE for online access, 2004. http://contentdm.lib.byu.edu/ETD/image/etd364.pdf.
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Rémillard, Michel. „Effect of hybrids, plant populations, rates of fertilizer and irrigation on soil test levels, field and nutrient uptake with corn (Zea mays L.) in Quebec“. Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61270.
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The purpose of this study was to investigate the effect of maize (Zea mays L.) hybrids, plant population, rates of fertilization and irrigation in 1984 and 1985 on soil test levels, soil pH, yield and yield components as well as nutrient uptake.High rates of fertilization increased soil test P and K but decreased soil test Ca and Mg and soil pH. Irrigation decreased soil test K, Ca and Mg. In both years maximum grain yields (at 15.5% moisture) were obtained when all factors were at high levels. Hybrid Pioneer 3925 and and hybrid CO-OP 2645 produced a maximum yield of 11.9 and 15.2 Mg ha$ sp{-1}$ in 1984 and 1985, respectively. Increasing plant population alone increased grain yield from 9.6 to 10.4 Mg ha$ sp{-1}$ in 1984, bu increases in grain yield with high plant population in 1985 could only be obtained when high rate of nutrients and supplemental irrigation were applied.
Nutrient uptake was usually greater for hybrid 2645 than hybrid 3925 in 1985, and greater for hybrid 3925 than for hybrid 3949 in 1984. Increasing plant population, rate of fertilization as well as available soil moisture generally brought about greater nutrient uptake. Ear leaf nutrient concentration at silking time was influenced by these factors but the differences obtained were not agronomically significant.
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Priddy, Lucy Phillips. „Evaluation of Precast Portland Cement Concrete Panels for Airfield Pavement Repairs“. Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/56952.
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Both the identification and validation of expedient portland cement concrete (PCC) repair technologies have been the focus of the pavements research community for decades due to ever decreasing construction timelines. Precast concrete panel technology offers a potential repair alternative to conventional cast-in-place PCC because the panel is fully cured and has gained full strength prior to its use. This repaired surface may be trafficked immediately, thus eliminating the need for long curing durations required for conventional PCC. The literature reveals a number of precast PCC panel investigations in the past 50 years; however precast technology has only recently gained acceptance and increased use in the US for highway pavements. Furthermore, only limited information regarding performance of airfield applications is available. Following a review of the available technologies, an existing panel prototype was redesigned to allow for both single- and multiple-panel repairs. A series of various sized repairs were conducted in a full-scale airfield PCC test section. Results of accelerated testing indicated that precast panels were suitable for airfield repairs, withstanding between 5,000 and 10,000 passes of C-17 aircraft traffic prior to failure. Failure was due to spalling of the transverse doweled joints. The load transfer characteristics of the transverse joint were studied to determine if the joint load test could be used to predict failure. Results showed that the load transfer efficiency calculations from the joint load test data were not useful for predicting failure; however differential deflections could possibly be applied. Additionally, the practice of filling the joints with rapid-setting grout may have resulted in higher measurements of load transfer efficiency. To determine the stresses generated in the doweled joint, three-dimensional finite element analyses were conducted. Results indicated that the dowel diameter should be increased to reduce stresses and to improve repair performance. Finally, the precast repair technology was compared to other expedient repair techniques in terms of repair speed, performance, and cost. Compared to other methods, the precast panel repair alternative provided similar return-to-service timelines and traffic performance at a slightly higher cost. Costs can be minimized through modification to the panel design and by fabricating panels in a precast facility. Modifications to the system design and placement procedures are also recommended to improve the field performance of the panels.Ph. D.
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Petty, David A. „Full-Scale Testing of 40 Year Old Prestressed AASHTO Girders That Have Been Retrofitted in Shear by Externally Applied Carbon Fiber Reinforced Polymer Wraps“. DigitalCommons@USU, 2010. https://digitalcommons.usu.edu/etd/629.
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The Utah Department of Transportation (UDOT) is interested in the application of rehabilitation techniques to strengthen their AASTHO prestressed bridge girders for shear. Utah's bridges are exposed to deterioration from rain, snow, and the introduction of salt for ice removable. This requires innovative rehabilitation techniques to address the deteriorations of their highway bridges, especially the ends of bridge girders where water and salt are more common due to construction joints. Carbon Fiber Reinforced Polymers (CFRP) are becoming more prevalent as a tool in highway bridge rehabilitation. This research investigates the application of various CFRP systems that can be used as shear reinforcement for prestressed concrete girders. The experimental program involved full-scale destructive testing of six 40-year-old, AASHTO prestressed I-girders that were salvaged from the 45th South/I-215 bridge in Salt Lake City, Utah. The testing involved retrofitting five of the girders with various configurations of CFRP fabric. Based on the initial tests, the most effective configuration was then applied to another set of I-shaped concrete girders for verifications. After the experimental testing, two analytical models developed for predicting the additional shear contribution of the CFRP reinforcement were compared with the measured results from the experimental program. After testing and comparisons, a CFRP reinforcement configuration and theoretical model was selected as a reliable and effective method for application of external shear reinforcement of AASHTO prestressed I-shaped girders.