Made available in DSpace on 2015-03-26T13:27:54Z (GMT). No. of bitstreams: 1 texto completo.pdf: 4751258 bytes, checksum: 0e480b21213f063f9d31d1243a36f77a (MD5) Previous issue date: 2010-06-29 / This paper aims to analyze the Ground Penetrating RADAR as tool in the determination of the thickness of the layers of the flexible road pavement of automatic way and the density of the asphalt layer supported by integrated testing of GPR and geotechnical data. The first experiment was conducted at the Presidente Dutra highway (BR116), Pirai - RJ, while the data for the second experiment were obtained from the BR040 highway, Sete Lagoas - MG. In order to achieve the objectives of this study, two methodologies were developed: the first one, directed to the identification of the thicknesses of the layers of flexible pavements of automated way; the second one, focused on determining the density of the layer of asphalt surfaces. The first methodology showed promising results, once it presented good classification results for the classes 1 (off-set) and 3 (macadam), however, was confusion between the "blocks" classified for the classes 2 (asphalt) and 4 (subgrade). A possible alternative, for improvement, would be: to use other texture extractor of the wavelet transform family; to use another type of interpolation, using a that better represents the trends of the coefficients to be generated the surface; to increase the number of training and testing samples, or even to use another type of classifier, such as Artificial Neural Networks. However, this is a field that is worth being investigated more deeply, since the results proved to be significant. The second methodology, regarding the correlation of the density of the asphalt layer through the dielectric value, measured by means an ground coupled antenna, of 1,6GHz, using the technique of the reflection, it presented satisfactory values in spite of the few sampling points, showing to be a good alternative to determine indirectly the density of the asphalt layer and for future works in the area. / Este trabalho tem o propósito de analisar o desempenho do RADAR de penetração no solo como ferramenta na determinação das espessuras das camadas do pavimento rodoviário flexível de maneira automática e a densidade da camada de revestimento apoiado em testes integrados de GPR e dados geotécnicos. O primeiro experimento foi realizado na rodovia Presidente Dutra (BR116), município de Piraí - RJ, em quanto os dados para o segundo experimento foram obtidos na rodovia BR040, município de Sete Lagoas - MG. Para atingir os objetivos do trabalho foram elaboradas duas metodologias: a primeira delas, direcionada à identificação das espessuras das camadas de pavimentos flexíveis de modo automatizado; a segunda, voltada para a determinação da densidade da camada de revestimento asfáltico. A primeira metodologia apresentou, de uma maneira geral, resultados promissores, uma vez que foram bons os resultados de classificação para as classes 1 (off-set) e 3 (macadame), no entanto, houve confusão entre os “blocos” classificados para as classes 2 (revestimento) e 4 (subleito). Uma possível alternativa para a melhoria dos resultados seria mudar o extrator de textura utilizado (transformada wavelet), valeria apena testar outros extratores da família wavelet; outra opção seria utilizar outro tipo de interpolador, usando um que pegue mais as tendências dos coeficientes ao se gerar a superfície; também seria interessante aumentar o número de amostras de treinamento e teste, ou até mesmo, utilizar outro tipo de classificador, como por exemplo, Redes Neurais Artificiais. Todavia, esse é um campo que vale ser pesquisado mais profundamente, uma vez que os resultados alcançados se mostraram esperançosos. A segunda metodologia, referente à correlação da densidade da camada de revestimento através do valor dielétrico, medido por meio de uma antena de contato no solo, de 1,6 GHz, utilizando a técnica da reflexão, apresentou valores satisfatórios apesar dos poucos pontos amostrados, mostrando ser uma boa escolha para se determinar a densidade da camada de revestimento de maneira indireta e para trabalhos futuros na área.

A presente tese de doutoramento versa sobre o estudo das propriedades geotécnicas de solos residuais não saturados ocorrentes no município de Ubatuba, litoral norte do Estado de São Paulo. O estudo das propriedades geotécnicas foi realizado a partir de uma abordagem macro e micromorfológica, buscando estabelecer a relação existente entre a água presente no solo e sua variação sazonal. Os procedimentos e técnicas utilizadas permitiram diferenciar os horizontes de intemperismo quanto à microestrutura e porosidade, bem como caracterizar seus comportamentos físico e hídrico. Os ensaios geotécnicos, in situ e em laboratório, forneceram informações importantes sobre as propriedades dos materiais, tais como: índices físicos, distribuição granulométrica, limites de Atterberg, curvas de retenção de água e condutividade hidráulica saturada. Os dados registrados pelos equipamentos instalados no campo (pluviômetros, sensores GMS e FDR) permitiram avaliar a relação existente entre os eventos pluviométricos com a distribuição de umidade e sucção matricial ao longo dos perfis de alteração. Além disso, utilizouse metodologia geofísica de forma inédita na geotecnia brasileira para a determinação de perfis de umidade em solos residuais tropicais. Em termos gerais, os resultados obtidos permitiram estabelecer algumas relações entre as propriedades mecânicas e hidráulicas e as peculiaridades micromorfológicas dos horizontes de solos. Os resultados desse trabalho poderão ainda indicar áreas prioritárias para o monitoramento das variáveis climatológicas e geotécnicas, podendo fornecer apreciáveis subsídios para um futuro aperfeiçoamento dos parâmetros técnicos utilizados em Planos Preventivos de Defesa Civil (PPDC). / This doctoral thesis focusing on the study of the geotechnical properties of unsaturated residual soils occurring in the municipal district of Ubatuba, north coast of the State of Sao Paulo. The study of geotechnical properties was conducted from a macro and micromorfology approach, seeking to establish the relationship between the water present in the residual soil and its seasonal variations. The procedures and techniques enabled differentiate the horizons of weathering in relation to the microstructure and porosity, and characterize its physical-hydraulic behaviours. The laboratory and in situ geotechnical tests, provided important information about the properties of materials, such as: physical index, grain-size distribution, Atterberg limits, water retention curve and saturated hydraulic conductivity. The data registered by equipments installed in the field (pluviometers, FDR and GMS sensors) enabled to evaluate the relationship between the rainfall events with the distribution of moisture and suction matrix along the soil profiles. In addition, was used geophysical methodology in order unprecedented in brazilian geotechnical for the determination of moisture profiles in residual tropical soils. Overall, the results allowed establish some relationship between the hydraulic and mechanical properties and the micromorphological peculiarities of the horizons of soils. The results of this study may also indicate priority areas for monitoring the climatological and geotechnical variables, and may provide appreciable subsidies for a future improvement of the technical parameters used in Civil Defense Prevention Plans (PPDC).

Climate change in the Arctic and sub-Arctic has induced substantial changes in the inland cryosphere. The warming climate is causing a reduction in glacier size and extent and the average net mass balance for Arctic glaciers have been negative over the past 40 years. Relatively few studies have been conducted concerning the development of the thermal distribution in glaciers during extensive volume changes. There is a possible diversity in how the thermal structure might change with a changing climate. Storglaciären is losing the cold surface layer in the ablation area and progressively becomes more temperate, while Kårsaglaciären is losing the zone of temperate ice in the ablation area and consequently becoming colder. The overall objective of this study has been to improve the understanding of the thermal response of polythermal glaciers to climate change. The results from Pårteglaciären, northern Sweden, indicate a decrease in volume by 18% in the last 15 years with an expected decrease of 35% of its present size during the coming century. As a consequence of the prevailing climate and volume decrease Pårteglaciären is experiencing a thinning of the cold surface layer at an average rate of 1.13 m a-1. The volumetric and cold surface layer changes are in the same magnitude, which may indicate that the CTS adapts relatively rapidly to the present changes. Assuming a climatic effect similar to what has been observed on Storglaciären, it can be concluded that the thinning has influenced the thermal regime. But in contrast to Kårsaglaciären, the thermal distribution on Pårteglaciären has become more temperate as a result of the substantial mass loss. / Klimatförändringar i Arktis och subarktis har orsakat stora förändringar i kryosfären. Ett varmare klimat orsakar en minskning av glaciärers storlek och omfattning och nettomassbalansen för Arktiska glaciärer har varit negativ under de senaste 40 åren. Relativt få studier har genomförts angående utvecklingen av den termiska fördelningen i glaciärer under omfattande volymförändringar. Det finns en möjlig diversitet i hur den termiska strukturen kan ändras med ett förändrat klimat. Storglaciären förlorar det kalla ytskiktet i ablationsområdet och blir successivt mer tempererad, medan Kårsaglaciären förlorar zonen med tempererad is i ablationsområdet och blir därmed kallare. Syftet med den här studien har varit att öka förståelsen för den termiska reaktionen hos polytermala glaciärer till ett förändrat klimat. Resultaten från Pårteglaciären i norra Sverige visar en volymreducering med 18% under de senaste 15 åren med en förväntad minskning på 35% av den nuvarande storleken under det kommande århundradet. Som en följd av det rådande klimatet och den reducerade volymen genomgår det kalla ytskiktet på Pårteglaciären en förtunning med en genomsnittlig hastighet av 1.13 m a-1. Volymförändringarna och förändringarna i kalla ytskiktet är i samma storleksordning, vilket tyder på att CTS anpassas relativt snabbt till de nuvarande förändringarna. Förutsatt en klimatisk effekt liknande den som observerats på Storglaciären, kan slutsatsen dras att förtunningen har påverkat den termiska regimen. Men i motsats till Kårsaglaciären har den termiska fördelningen på Pårteglaciären blivit mer tempererad som ett resultat av den omfattande massförlusten.

Abstract This PhD thesis is composed of a synopsis and five published papers that are focused on both the research results of studies on electrical properties of road materials and subgrade soils and their seasonal changes and the use of Ground Penetrating Radar technique in traffic infrastructure surveys. The data for this survey was collected mainly in Finland, Texas, Scotland and Sweden and thus presents many kinds of road materials, subgrade soils and climate conditions. The synopsis of this work begins with a presentation of the theory and basic principles of GPR techniques. Special attention is given to the dielectric properties and seasonal changes of unbound road materials and subgrade soils. The synopsis also presents different kinds of GPR hardware systems as well as recommendations and experiences from different data collection, processing and interpretation techniques. Special attention is given to a method whereby GPR data is integrated with other road survey data and then analysed using a number of structural diagnostic methods. Finally, the synopsis provides an overview of of the various GPR applications on roads and streets, bridges, railways and airports. The laboratory test results presented in this work show that the relationship between dielectric value and increasing water content is not linear or exponential but more likely a series of logarithmic functions. Laboratory results also showed that dielectric dispersion, which can be related to poorly performing subgrade soils and road aggregates, takes place mainly in loosely bound adsorption water and capillary water layer. As such these moisture sensitive problem materials can also be identified during the dry summer seasons when they are stiff. Dielectric value and electrical conductivity can also be related to other technical properties of road materials and subgrade soils such as frost susceptibility, shear strength, plastic limit, compaction degree and voids content. Laboratory tests and field data collected using the Percostation technique also demonstrate that a knowledge of seasonal changes and thermodynamics is very important in understanding and modelling the mechanical behaviour of road structures. Finally, laboratory and field tests indicate that colloids have an important role in the failure mechanism of the road materials. This research demonstrates that the GPR technique not only gives valuable structural information on the different types of structures and subgrade soils but it provides a wide range of information of the electrical properties of the materials under survey which can be further related to their mechanical performance. The best information will be gained if GPR data is analysed together with other non destructive testing data collected form the roads, railways and airports.

This dissertation is focused on the research of the applicability of the thermographic method in the diagnosis of concrete bridges in the Czech Republic. The theoretical part characterizes selected defects of concrete structures and the principle of their detection. The practical part describes the measurements made in the laboratory on the test specimen and the field on the concrete bridge. Most attention is paid to infrared thermography, ground-penetrating radar and ultrasonic pulse-echo method. Based on the results of the dissertation, recommendations for the use of the thermographic test method in practice were developed.

The subject of this final thesis is the diagnostic survey of the prefabricated hall made of framed concrete in the areal of Fatra Chropyně. The thesis contains description of construction and technological survey and diagnostic methods. The practical part contains material assessing of chosen elements of construction (beam, column,precast floor slab). It is also focused on localization of position and diameter of reinforcement. Last step is focused on quality of the concrete, particularly compressive strength and strenght class of concrete.

La contamination par les hydrocarbures peut altérer les propriétés physicochimiques et biologiques du sous-sol, par conséquent le diagnostic et l’évolution des contaminants peuvent être surveillés en couplant les analyses géochimiques et les techniques géophysiques. Dans ce travail, différentes méthodes géophysiques de sub-surface telles que la tomographie de résistivité électrique, la polarisation induite, le géoradar et le potentiel spontané ont été utilisées d’une manière combinée pour localiser les zones impactées par les hydrocarbures du site de l’ancienne raffinerie de Petit Couronne. Les investigations géophysiques par la tomographie de résistivité électrique en 2D ont révélés la présence des anomalies de fortes valeurs de conductivité et chargeabilité électrique associés aux zones contaminées de l’aquifère. Les résultats obtenus avec les profils d’ERT et IP indiquent que la contamination a modifié les parties capacitives et ohmiques de la conduction électrique dans les sédiments contaminés. Cette signature très conductrice des zones contaminées est due aux processus de biodégradation des hydrocarbures qui minéralisent les eaux de l’aquifère. Les panaches d’hydrocarbures ont été identifiés sur les profils de géoradar par une forte atténuation des amplitudes de signaux électromagnétiques. Les profils de potentiel spontané ont aussi fourni une cartographie spatiale des zones contaminées par leurs signatures électriques négatives qui est associées aux processus d'oxydoréduction et biodégradation à l’interface entre la zone non saturée et saturée. Une carte de potentiel redox a été reconstruite à partir de l'inversion des données résiduelles de potentiel spontané grâce au calcul des composantes de la densité du courant électrique. La contribution redox dans l'aquifère contaminé s'explique par des dipôles verticaux répartis sur la frange capillaire juste au-dessus de la nappe phréatique, en favorisant le mécanisme de la biogéobatterie sur ce site. L’ensemble de ces résultats ont été confirmés par les mesures géochimiques menées au niveau des forages. L'étude a montré que les altérations biologiques des hydrocarbures ont modifié les propriétés chimiques de l'eau porale et que l'étendue de la contamination des eaux souterraines peut être délimitée à partir du contraste géophysique observé entre les zones contaminées et les zones non contaminées. La combinaison des différentes méthodes géophysiques avec des analyses géochimiques ponctuelles au niveau des forages ont permis de mieux comprendre les différents processus qui sont à l’origine de modifications des propriétés biogéochimiques dans les sols et les eaux souterraines. / The presence of hydrocarbon contamination in the subsurface can modify the physiochemical and biological properties of soil and groundwater. The sensitivity of geophysical methods to biogeochemical changes occurring in contaminated media can be used to monitor hydrocarbon contamination in a fast and inexpensive way. As such, geophysical methods including, electrical resistivity tomography, induced polarization, ground penetrating radar, self-potential and magnetic susceptibility were used in this work to characterize the hydrocarbon contamination and investigate its effects on the soil and groundwater geophysical and geochemical properties at a site impacted by an aged hydrocarbon plume. The geophysical response to hydrocarbon contamination varies according to factors related to the contaminant in question and to the contaminated environment. Therefore, to achieve a better interpretation, the field geophysical data were constrained by geochemical soil boring data which showed that biodegradation is occurring in the site. This was shown through observing elevated total dissolved solids concentrations, elevated groundwater electrical conductivity values, negative redox potential values and depleted terminal electron acceptors concentrations in the contaminated locations. Throughout the investigation, the geophysical measurements supported the conductive model and consistently recorded low resistivity anomalies, high chargeability values and attenuated GPR reflections in the contaminated zones. Additionally, significant negative self-potential anomalies associated with oxidation-reduction processes coupled to the biodegradation of hydrocarbons were recorded in the groundwater contaminated zone. Based on this observation, a redox potential map of the contaminated site was constructed by the inversion of the field self potential data. Throughout the process, a groundwater model was first calibrated to remove the electrokinetic component from the SP signal. Then, the obtained residual self potential data was inverted for the electrical current density by using an inversion algorithm which includes minimizing a cost function with a data misfit contribution and a regularizer. As a result, the obtained current density was used to construct a map of redox potential showing the borders and the redox front of the contaminant plume. The redox contribution was explained by vertical dipoles distributed across the capillary fringe, supporting further the mechanism of bio-geo-battery which was created due to the existence of a strong redox potential gradient between the highly reducing conditions within the plume and the oxidizing conditions outside the plume. Furthermore, elevated magnetic susceptibility values were recorded in the biologically active transition zone where bio-precipitation of iron minerals is occurring. Given these results, this study showed that biological alterations of hydrocarbons induced subtle changes in the pore water biogeochemistry, which consequently modified the geophysical properties of the contaminated sediments. The extent of groundwater contamination was delineated according to the geophysical contrast between the contaminated and clean zones. Moreover, the combination of the different geophysical methods, constrained by the geochemical point measurements, provided insight on the different processes which might have modified the soil and groundwater biogeochemical properties at the contaminated site.

Un géoradar (GPR) effectue une détection non destructive d'objets enfouis, ou l'imagerie du sous-sol par transmission d'ondes électromagnétiques et la détection et l'analyse des réflexions. Le principal défi de GPR est la réduction de la portée de détection en raison de l'atténuation du signal grave causée par la conductivité du sous-sol qui devient plus sévère dans les hautes fréquences. Afin d'augmenter la portée de détection, GPR utilise des fréquences plus basses que les radars non-GPR et nécessite donc de plus grandes antennes qui peuvent limiter la portabilité du système. La plupart des systèmes utilisent des radars GPR à impulsion mais le FMCW (onde continue à fréquence modulée) radar peut présenter certains avantages tels que la versatilité de la fréquence, une maintenance réduite du système et une meilleure résolution de gamme. Les fréquences inférieures à 1 GHz ont d'abord été rares en radars de courte portée FMCW mais trouvent maintenant leur chemin de retour dans des systèmes comme ultra-large bande (UWB) pénétrant dans le sol des radars pour la détection des mines et ainsi que d'autres applications. Lorsque les mesures sont effectuées sur des véhicules, de grands appareils d'antenne ne sont pas un problème. La portabilité, cependant, peut devenir un problème dans les études géophysiques ou des travaux d'urgence dans laquelle on peut avoir besoin de transporter le système par des endroits accidentés, inexplorés et / ou dangereux sans accès aux véhicules. Des environnements inaccessibles peuvent nécessiter la manœuvrabilité à travers d’obstacles (montagnes, grottes, lacs, zones rocheuses). D’ailleurs, l’installation rapide du système est critique dans des conditions difficiles telles que les températures extrêmes, où le temps d'exposition est coûteux et le temps de mesure limité. Une solution pour améliorer la portabilité et la capacité de déploiement d'un système GPR est de réaliser un système complet sur un substrat qui est enroulable afin de permettre une transportation facile. L’électronique sur substrat flexible a déjà été utilisée dans des applications militaires et des sports en plein air. Actuellement, il y a quelques technologies disponibles pour réaliser l'électronique flexible qui ont été un thème majeur en recherche, chacune avec différents niveaux d'intégration. La technologie d'impression à jet d'encre offre une méthode efficace, polyvalente et rentable pour la réalisation de dispositifs flexibles. Dans ce travail, un système radar FMCW classique a été conçu et un travail présenté, pour la première fois, d’application de la technologie d'impression à jet d'encre sur un système de radar. Le système est appelé un système de radar monolithique portable dans lequel tous les agents actifs, passifs et l'antenne sont destinés à partager le même substrat enroulable continu. Ainsi, une intégration hybride est utilisée pour étudier la fiabilité et la performance du système complet enroulé autour d’un rayon serré. Plusieurs défis de conception d'un grand système ont été surmontés qui donneront un aperçu de nouveaux modèles au fur et à mesure que le niveau d'intégration à l'aide de la technologie d'impression à jet d'encre continue d’augmenter. / Flexible monolithic ultra-portable ground penetrating radar using inkjet printing technology A Ground Penetrating Radar (GPR) performs nondestructive detection of buried objects, or subsurface imaging by transmitting electromagnetic waves and detecting and analyzing the reflections. The main challenge of GPR is the reduction in detection range due to the severe signal attenuation that is caused by subsurface conductivity that becomes more severe at high frequencies. In order to increase the detection range, GPR uses lower frequencies than non-GPR radars and thus requires larger antennas that may limit system portability. Most GPR systems use impulse radars however the FMCW (frequency modulated continuous wave) radar can provide some advantages such as frequency versatility, reduced system maintenance and improved range resolution. Frequencies below 1 GHz were initially uncommon in short-range FMCW radars but are now finding their way back in systems such as ultra-wideband (UWB) ground penetrating radars for mine detection and as well as other applications. When measurements are performed on vehicles, large antenna fixtures are not a problem. Portability, however, can become an issue in geophysical studies or emergency work in which one may need to transport the system through rugged, unexplored and/or hazardous locations without vehicle access and perform measurements. Inaccessible environments may require climbing up and down, squeezing through, jumping over, crawling under, maneuvering through or swimming through obstacles (mountains, caves, lakes, rocky areas). In addition to transportation, rapid system setup is critical in difficult conditions such as freezing temperatures or extreme heat where exposure time is costly and limits measurement time. One solution to enhance the portability and deployability of a GPR system for wide area rugged measurements is to realize a complete system on a continuous substrate that is rollable around a reasonably small radius and storable in a scroll or poster-like fashion for easy backpack transportation. Electronics that can flex and bend have already used in military applications and for outdoor sporting gear. Currently, there are a few types of technology available to realize flexible electronics that have been a major topic of research, each with different levels of integration. Inkjet printing technology offers a cost effective, versatile and efficient method for realizing flexible devices. In this work a classical FMCW radar system is designed and an effort is made, for the first time, to apply inkjet printing technology to a radar system. The system is referred to as a portable monolithic radar system in which all actives, passives and antenna are meant to share the same continuous rollable substrate. In doing this, a medium level of integration is used to investigate limits of system complexity, resolution and ultra miniaturization for tight rollability. Various design challenges of a large system are overcome that will hopefully give insight to new designs as the integration level using inkjet printing technology increases.

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