The geometry, deformation mechanism and kinematics of the S&uuml / rg&uuml / Fault Zone is investigated by using remotely sensed data including Landsat TM and ASTER imagery combined with SRTM, and stereo-aerial photographs. They are used to extract information related to regional lineaments and tectono-morphological characteristics of the SFZ. Various image processing and enhancement techniques including contrast enhancement, PCA, DS and color composites are applied on the imagery and three different approaches including manual, semi automatic and automatic lineament extraction methods are followed. Then the lineaments obtained from ASTER and Landsat imagery using manual and automatic methods are overlaid to produce a final lineaments map. The results have indicated that, the total number and length of the lineaments obtained from automatic is more than other methods while the percentages of overlapping lineaments for the manual method is more than the automatic method which indicate that the lineaments from automatic method does not discriminate man made features which result more lineaments and less overlapping ratio with respect to final map. It is revealed from the detail analysis that, the SFZ displays characteristic deformation patterns of strike-slip faults, such as pressure ridges, linear fault controlled valleys, deflected stream courses, rotated blocks and juxtaposition of stratigraphical horizons in macroscopic scale. In addition to these, kinematic analyses carried out using fault slip data indicated that the S&uuml / rg&uuml / Fault Zone is dextral strike-slip fault zone with a reverse component of slip and cumulative displacement along the fault is more than 2 km.

Carbon nanotubes are molecular-scale tubes of graphitic carbon that possess many unique properties. They have high tensile strength and elastic modulus, are thermally and electrically conductive, and can be structurally modified using well established carbon chemistries. There is global interest in taking advantage of their unique combination of properties and using these interesting materials as components in nanoscale devices and composite materials. The goal of this research was the correlation of the mechanical properties of coiled carbon nanotubes with their chemical structure. Individual nanocoils, grown by chemical vapor deposition, were attached to scanning probe tip using the arc discharge method. Using a scanning probe microscope the nanocoils are repeatedly brought into and out of contact with a chemically-modified substrate. Precise control over the length (or area) of contact with the substrate is achievable through simultaneous monitoring the cantilever deflection resonance, and correlating these with scanner movement. The mechanical response of nanocoils depended upon the extent of their compression. Nonlinear response of the nanocoil was observed consistent with compression, buckling, and slip-stick motion of the nanocoil. The chemical structure of the nanocoil and its orientation on the tip was determined using scanning and transmission electron microscopy. The mechanical stiffness of eighteen different nanocoils was determined in three ways. In the first, the spring constant of each nanocoil was computed from the slope of the linear response region of the force-distance curve. The assumptions upon which this calculation is based are: 1) under compression, the cantilever-nanocoil system can be modeled as two-springs in series, and 2) the nanocoil behaves as an ideal spring as the load from the cantilever is applied. Nanocoil spring constants determined in this fashion ranged from 6.5x10-3 to 5.16 TPa for the CCNTs understudy. In the second, the spring constant of the nanocoil was computed from measuring the critical force required to buckle the nanocoil. The critical force method measured the force at the point where the nanocoil-cantilever system diverges from a linear region in the force curve. Nanocoil spring constants determined in this fashion ranged from 1.3x10-5 to 10.4 TPa for the CCNTs understudy. In the third, the spring constant of each nanocoil was computed from the thermal resonance of the cantilever-nanocoil system. Prior to contact of the nanocoil with the substrate, the effective spring constant of the system is essentially that of the cantilever. At the point of contact and prior to buckling or slip-stick motion, the effective spring constant of the system is modeled as two springs in parallel. Nanocoil spring constants determined in this fashion ranged from 2.7x10-3 to 0.03 TPa for the CCNTs understudy. Using the thermal resonance of the cantilever system a trend was observed relating nanocoil structure to the calculated modulus. Hollow, tube-like nanostructures had a higher measured modulus than solid or fibrous structures by several orders of magnitude. One can conclude that the structure of carbon nanocoils can be determined from using their mechanical properties. This correlation should significantly contribute to the knowledge of the scientific and engineering community. It will enable the integration of carbon nanocoils in microelectromechanical (MEMS) or nanoelectromechanical systems (NEMS) as resonators, vibration dampers, or any other application in which springs are used within complex devices.

Mining induced seismic activity and rockbursting are critical concerns for many underground operations. Seismic activity may arise from the crushing of highly stressed volumes of rock around mine openings or from shear motion on planes of weakness. Shear-slip on major planes of weakness such as faults, shear zones and weak contacts has long been recognized as a dominant mode of failure in underground mines. In certain circumstances, it can generate large seismic events and induce substantial damage to mine openings. The Big Bell Gold mine began experiencing major seismic activity and resultant damage in 1999. Several seismic events were recorded around the second graphitic shear between April 2000 and February 2002. It is likely that the seismic activity occurred as a result of the low strength of the shear structure combined with the high level of mining induced stresses. The stability of the second graphitic shear was examined in order to gain a better understanding of the causes and mechanisms of the seismic activity recorded in the vicinity of the shear structure as mining advanced. The data were derived from the observation of the structure exposures, numerical modelling and seismic monitoring. The numerical modelling predictions and the interpreted seismic monitoring data were subsequently compared in order to identify potential relationships between the two. This thesis proposes the Incremental Work Density (IWD) as a measure to evaluate the relative likelihood of shear-slip induced seismic activity upon major planes of weakness. IWD is readily evaluated using numerical modelling and is calculated as the product of the average driving shear stress and change in inelastic shear deformation during a given mining increment or step. IWD is expected to correlate with shear-slip induced seismic activity in both space and time. In this thesis, IWD was applied to the case study of the second graphitic shear at the Big Bell mine. Exposures of the second graphitic shear yielded information about the physical characteristics of the structure and location within the mine. Numerical modelling was used to examine the influence of mining induced stresses on the overall behaviour of the shear structure. A multi-step model of the mine was created using the three- dimensional boundary element code of Map3D. The shear structure was physically incorporated into the model in order to simulate inelastic shear deformation. An elasto-plastic Mohr-Coulomb material model was used to describe the structure behaviour. The structure plane was divided into several elements in order to allow for the comparison of the numerical modelling predictions and the interpreted seismic data. Stress components, deformation components and IWD values were calculated for each element of the shear structure and each mining step. The seismic activity recorded in the vicinity of the second graphitic shear was back analysed. The seismic data were also gridded and smoothed. Gridding and smoothing of individual seismic moment and seismic energy values resulted in the definition of indicators of seismic activity for each element and mining step. The numerical model predicted inelastic shear deformation upon the second graphitic shear as mining advanced. The distribution of modelled IWD suggested that shear deformation was most likely seismic upon a zone below the stopes and most likely aseismic upon the upper zone of the shear structure. The distribution of seismic activity recorded in the vicinity of the shear structure verified the above predictions. The seismic events predominantly clustered upon the zone below the stopes. The results indicated that the seismic activity recorded in the vicinity of the second graphitic shear was most likely related to both the change in inelastic shear deformation and the level of driving shear stress during mechanical shearing. Time distribution of the seismic events also indicated that shear deformation and accompanying seismic activity were strongly influenced by mining and were time-dependant. Seismic activity in the vicinity of the second graphitic shear occurred as a result of the overall inelastic shear deformation of the shear structure under mining induced stresses. A satisfactory relationship was found between the spatial distribution of modelled IWD upon the shear structure and the spatial distribution of interpreted seismic activity (measured as either smoothed seismic moment or smoothed seismic energy). Seismic activity predominantly clustered around a zone of higher IWD upon the second graphitic shear as mining advanced. However, no significant statistical relationship was found between the modelled IWD and the interpreted seismic activity. The lack of statistical relationship between the modelled and seismic data may be attributed to several factors including the limitations of the techniques employed (e.g. Map3D modelling, seismic monitoring) and the complexity of the process involved.

Made available in DSpace on 2014-06-11T19:28:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-07-08Bitstream added on 2014-06-13T19:58:20Z : No. of bitstreams: 1 silva_lh_me_sjc.pdf: 2510222 bytes, checksum: 9b0884b924775ed48bb9667a27133675 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo deste estudo foi desenvolver um novo formato de pilar protético estético em zircônia (3Y-TZP) visando suprimir a utilização do parafuso trespassante utilizado no formato convencional de pilares protéticos em zircônia. Inicialmente foi feita a caracterização do material utilizado na técnica de colagem de barbotina (slip casting) através da confecção de uma barra que teve suas propriedades mecânicas, módulo de elasticidade (E) e coeficiente de Poisson (), grau de contração e dimensão de suas partículas após sinterização avaliados pelos métodos de frequências naturais de vibração e microscopia eletrônica de varredura (MEV), respectivamente. Previamente à confecção do pilar protótipo, este teve seu comportamento mecânico avaliado e comparado a um pilar de 3YTZP convencional com parafuso trespassante pela análise por elementos finitos (FEA) durante sua instalação em implante e recebendo carga oblíqua simulando força de mastigação (210,5 N). O protótipo foi confeccionado pela técnica de colagem de barbotina em um molde de gesso obtido a partir de uma duplicata ampliada em cera. A densidade final foi avaliada pelo método de Archimedes em água. Obteve-se o módulo de elasticidade de 187,97 ± 4,84 GPa e coeficiente de Poisson de 0,19 ± 0,04 para o material. O grau de contração de sinterização foi de 58 vol% e o tamanho do grão foi de 0,705 ± 0,424 μm. Na análise por FEA verificou-se concentrações de tensões na região inicial da rosca para ambos os pilares, e durante o carregamento foram observadas tensões de tração no lado em que incidiu a carga, com presença de tensões de compressão no lado oposto. Ainda, observou-se durante o carregamento do pilar protético convencional concentração de tensão na região do pescoço do parafuso trespassante. A densidade final obtida para o pilar protótipo em 3Y-TZP foi de 95,68% em... / The purpose of this study was to develop a new esthetic zirconia (3YYTZP) implant abutment shape to suppress the use of the fixing screw commonly used by the conventional zirconia abutments. A material characterization, Young’s modulus (E), Poisson’s rate (), shrinkage and particles dimensions after sintering was performed for a bar shape specimen obtained by slip casting evaluated by the natural torsional and flexural vibration frequencies and scanning electron microscope (SEM), respectively. Previously to the prototype abutment confection, its mechanical behavior was evaluated and compared to a conventional zirconia abutment with a fixing screw by finite element analisys (FEA) simulating the abutment installation and oblique loading (210.5 N). The prototype was confectioned by the slip casting technique using a gypsum mould obtained from a wax expanded replica. The abutment had its density measured by Archimedes’ method. Through the natural vibration frequencies a Young’s modulus of 187.97 ± 4.84 GPa and a Poisson’s rate of 0.19 ± 0.04 were obtained for the material. The shrinkage was 58 vol% and the grain size was 0,705 ± 0,424 μm . The FEA showed stress concentration at the first thread pitch for both abutments, and tensile stress concentration were observed at the side that received the oblique load with compressive stress at the opposite side. Whereas, for the conventional abutment model a stress concentration was observed at the screw’s stem. The final density for the zirconia prototype abutment was 95.68% from the theoretical density (6.12 g.cm-3). The zirconia abutment obtained by slip casting presented satisfactory physical properties. The suppressing of the fixing screw could provide better performance to the abutment due to the lack of stress concentration in the screw when an oblique load is applied, when evaluated by FEA

Made available in DSpace on 2015-03-26T13:28:34Z (GMT). No. of bitstreams: 1 texto completo.pdf: 2356282 bytes, checksum: ad31e25717381ce2f02be29b6927aafe (MD5) Previous issue date: 2014-06-06 / This paper deals with the monitoring of a slope of land under landslide risk in the Serra de São Geraldo, in the Zona da Mata Mineira. Anterior indications were taken during earthmoving work to repair deformations on a stretch of road that runs through Serra. The work was monitored by a second network of points located near the cracks detected in the soil, at three different times; this was made using a network of support, installed in an area that was not affected by slip assumption. In order to collect data it was used conventional survey associated with trigonometric leveling with total station and GPS survey. After adjustment of observations and the processing of the network, the ground shifts were identified. Through the analysis it was possible to identify displacements with values between 1 and 281 mm and with the aid of geostatistics it was possible to assess the spatial dependence of movements for periods of 50 and 61 days. Finally, displacement maps were generated using Kriging. / O presente trabalho trata do monitoramento de uma encosta de terra na Serra de São Geraldo, região da Zona da Mata mineira, cujo terreno apresentava risco de instabilidade. Os primeiros indícios de instabilidade do terreno se deram durante um trabalho de terraplenagem para correção de deformações em um trecho de estrada que segue através da Serra. A partir de uma rede de pontos de apoio, instalados em área não afetada pelo pressuposto deslizamento, foi monitorada uma segunda rede de pontos implantada próximo às fissuras detectadas no solo em três diferentes épocas. Para a coleta dos dados, utilizou-se levantamento convencional associado ao nivelamento trigonométrico com estação total e levantamento por GPS. Após o processamento e ajustamento das observações em rede, foram identificados deslocamentos do solo. Por meio das análises foi possível identificar deslocamentos com valores entre 1 e 281 milímetros e com o auxílio da geoestatística ainda foi possível avaliar a dependência espacial dos movimentos para períodos de 50 e 61 dias. Finalmente, foram gerados, a partir de Krigagem, os mapas de deslocamento, que representaram a instabilidade detectada na área.

Les liquides confinés présentent beaucoup de comportements fascinants, très différents de ceux qui sont observés dans leur volume. Le confinement peut induire un déplacement de l'équilibre des phases (par exemple de la transition liquide-vapeur, aussi appelé condensation capillaire), il peut modifier la température de transition vitreuses des polymères, ou bien imposer un ordre dans l'arrangement moléculaire du fluide. Les modifications des propriétés mécaniques des liquides aux interfaces sont particulièrement importantes au niveau des applications. Cependant au niveau de la compréhension, le simple cas des liquides newtoniens est toujours sujet à controverse, avec d'une part des simulations numériques montrant que la viscosité ne devrait pas être modifiée pour des confinements supérieurs à quelques tailles moléculaires, et d'autre part des expériences non unanimes, montrant parfois des modifications qualitatives des propriétés rhéologiques sous confinement. Récemment nous avons montré que les méthodes d'impédance hydrodynamique en géométrie sphère-plan constituent une méthode privilégiée, non-intrusive et non-ambigüe, pour aborder la nano-mécanique des liquides aux interfaces (1,2). S'agissant d'interphases, cad de couches fluides dont les propriétés sont modifiées par la proximité d'un solide, il est possible d'accéder à leur module sans contact, donc sans la perturbation apportée par une seconde surface. S'agissant de l'effet du confinement sur la rhéologie, nous avons montré que la déformation élastique à l'échelle du pico-mètre des surfaces confinantes, donne une forte modification de la rhéologie apparente du fluide, même en l'absence de tout effet intrinsèque. Le sujet de thèse vise à mettre en oeuvre les méthodes d'impédance hydrodynamique pour étudier la rhéologie de solutions de polymères confinés. On étudiera plus précisément deux systèmes modèles d'importance fondamentale aussi bien que pratique : les brosses de polymères greffés, dont les propriétés mécaniques sont un enjeu dans les applications de lubrification aussi bien que pour les écoulements biologiques, et les solutions de polymères hydro-solubles d'intérêt pour la récupération assistée du pétrole, en vue de comprendre les effets de fluidification sous confinement et de faire la part entre modification de la viscosité et couche de déplétion induite par l'écoulement. Au niveau instrumental, un des enjeux de la thèse sera de mettre en oeuvre les mesures d'impédance hydrodynamique sur deux types d'instruments complémentaires au niveau de l'échelle de la sonde: l'appareil de mesure de forces dynamique (SFA) du Liphy, et l'AFM à détection interférométrique développé à l'Institut Néel. Ces différentes échelles d'investigation devront permettre de préciser les propriétés moyennes mécaniques moyennes des liquides confinés et leurs gradients au voisinage de la paroi. Une perspective du travail sera de mettre en regard les propriétés mécaniques et rhéologiques intrinsèques des brosses polymères déterminées directement sur SFA ou AFM, avec leur propriétés fonctionnelles: propriétés de lubrification des contacts frottants, ou de modification des écoulements des dans micro-canaux. Ceci sera poursuivi sur la plateforme expérimentale mise en place par Lionel Bureau au Liphy : SFA de friction, systèmes micro-fluidiques à visée biomimétique (parois fonctionnalisées par des brosses polymères). L'enjeu sera alors de comprendre comment les propriétés mécaniques et rhéologiques des brosses déterminent celles des systèmes dans lesquels elles interviennent. / Liquids confined present many fascinating behaviors very different from those observed in their volume. Confinement can induce a shift in the balance of phases (eg the liquid-vapor transition, also called capillary condensation), it can change the glass transition temperature of the polymer, or impose order on the molecular arrangement of fluid. The changes in the mechanical properties of liquid interfaces are particularly important in applications. However the level of understanding, the simple case of Newtonian liquids is still controversial, with one hand, numerical simulations show that the viscosity should not be changed for some higher molecular sizes containment, and secondly non-unanimous experiences, sometimes showing qualitative changes in rheological properties under confinement. Recently we have shown that the methods of hydrodynamic impedance sphere-plane geometry is a privileged, non-intrusive method and unambiguous, to discuss the mechanics of nano-liquid interfaces (1,2). As interphase, ie fluid layers whose properties are modified by the proximity of a solid, it is possible to accede their contactless module, so without the disturbance caused by a second surface.S As regards the effect of confinement on the rheology, we have shown that the elastic deformation across the pico meter of confining surfaces, gives a strong modification beyond apparent rheology of the fluid, even in the absence of any intrinsic effect. The thesis aims to implement the hydrodynamic impedance methods to study the rheology of polymer solutions confined. We specifically consider two models of fundamental importance as well as practical systems: brushes grafted polymer whose mechanical properties are an issue in lubrication applications as well as for biological flows and solutions of water-soluble polymers interest in enhanced oil recovery, in order to understand the effects of thinning containment and to distinguish between changes in viscosity and depletion layer induced by the flow. At the instrumental level, one of the challenges of the thesis is to implement the hydrodynamic impedance measurements on two complementary instruments at the level of the probe: the measuring dynamic power (SFA) of Liphy, and AFM interferometric detection developed at the Institut Néel. These different scales of investigation will help to clarify the medium average mechanical properties of liquids confined and their gradients near the wall. A view of work will be to look mechanical and rheological properties of polymer brushes intrinsic determined directly on SFA or AFM with their functional properties: lubricating properties of sliding contacts, or modification of the flow in microchannels. This will continue on the implementation by Lionel Bureau Liphy experimental platform: SFA friction advised biomimetic micro-fluidic systems (walls functionalized polymer brushes). The challenge will be to understand how the mechanical and rheological properties of brushes determine those systems in which they operate.

[pt] Uma prospecção bem sucedida de petróleo e gás requer muitos esforços para se sobrepor os desafios encontrados, tais como vibrações axiais, laterais e torcionais. Estes fenômenos podem causar a falha prematura de componentes do sistema de perfuração, disfunção nos equipamentos de medição e aumento no tempo e custo no processo de perfuração. Em particular, vibrações torcionais estão presentes em grande parte dos processos de perfuração e podem alcançar um estado crítico: stick-slip. Um melhor entendimento sobre este fenômeno proporciona ferramentas para evitar o aumento do tempo e do custo da prospecção, assegurando o investimento e sucesso do processo de perfuração. Neste trabalho, é descrito um procedimento experimental com um atrito não linear objetivando induzir stick-slip e é feito uma modelagem analítica simples do problema. O modelo de atrito é baseado em um atrito seco imposto por um dispositivo de freio desenvolvido. O comportamento não linear da bancada experimental é analisada e o modelo numérico é validado comparando diagramas de bifurcações numérica e experimentais. / [en] A successful oil and gas prospecting requires many efforts to overcome the encountered challenges, some of these challenges include drill string axial, lateral and torsional vibrations. These phenomena may cause premature component failures of the drilling system, dysfunction of measurement equipments, and increase time and costs of the prospecting process. Torsional vibrations are present in most drilling processes and may reach a severe state: stick-slip. An improved understanding about the stick-slip phenomenon provides tools to avoid the increase of prospecting time and costs, assuring the investment and success of the drilling process. Firstly, a numerical analysis of the drill string is performed with different friction models. These models are proposed in order to get familiar with the drill string dynamics. Also, it is described the experimental procedure with a nonlinear friction aiming to induce stick-slip and is performed a simple analytical modeling of the problem. The friction model is based on dry friction imposed by a break device. The nonlinear behavior of the experimental apparatus is analyzed and the numerical model is validated comparing experimental and numerical bifurcation diagrams.

xv, 136 p. : ill. (some col.) / The Pacific Northwest of the United States has been tectonically and magmatically active with the accretion of the Farallon oceanic terrane "Siletzia" ∼50 Ma. The accretion of Siletzia terminated the flat-slab subduction of the Farallon slab and initiated the Cascadia subduction zone. In this dissertation, I focus on both the large-scale tectonic structures preserved seismically in the crust and upper mantle, and the small-scale, short-term aseismic processes on the plate interface. I measure the shear-wave splitting trends around eastern Oregon with a dataset of ∼200 seismometers from 2006-2008 to analyze the upper-mantle anisotropy. The delay times between splitted shear-waves range from 0.8 s to 2.7 s. In the High Lava Plains, the fast polarization direction is approximately E-W with average delay time ∼1.8 s. I infer that there must be significant active flow in a roughly E-W direction in the asthenosphere beneath this area. The splitting pattern is more variable and complicated in NE Oregon, where the crust and mantle lithosphere may be a significant contribution. In terms of the imaged seismic velocity structures, I infer that the Eocene sedimentary basins in south-central Washington lie above a magmatically underplated crust of extended Siletzia lithosphere. Siletzia thrusts under the pre-accretion forearc, and its southeast termination is especially strong and sharp southeast of the Klamath-Blue Mountains gravity lineament. Magmatic intrusion has increased upper crustal velocity as in the less active Washington Cascades, but the higher temperatures beneath the magmatically active Oregon Cascades have a dominating effect. To better understand the physical mechanism of slow slip events on the plate interface, I explore the scaling relationships of various source parameters collected mainly from subduction zones worldwide and also other tectonic environments. The source parameter scaling relationships of slow slip events highlight the similarities and differences between slow slip phenomena and earthquakes. These relationships hold implications for the degree of heterogeneity and fault healing characteristics. The recurrence statistics of northern Cascadia events behave weakly time predictable and moderately anti-slip predictable, which may indicate healing between events. This dissertation includes co-authored materials both previously published and submitted for publication. / Committee in charge: Eugene Humphreys, Chairperson; David Schmidt, Member; Ray Weldon, Member; James Isenberg, Outside Member

Fenômenos de deslizamentos de encostas ocorrem em todo o mundo em diversas condições climáticas e de terrenos, custando bilhões de dólares e produzindo milhares de mortes, agravando problemas ambientais, econômicos e políticos. Um problema sério que se associa à questão dos deslizamentos de encostas é o crescimento populacional e a ocupação desordenada das encostas, caracterizando os deslizamentos como uma questão geopolítica e econômica. Ações para mitigar os problemas decorrentes desses fenômenos de deslizamentos incluem o Monitoramento Ambiental das áreas de maior susceptibilidade e o Manejo da População, quando submetidas a elevado risco de deslizamento. Os processos de monitoração consistem na coleta de um conjunto de sinais e parâmetros, provenientes do solo das encostas, que possam ser usados para o reconhecimento das dinâmicas dos solos. Combinando os sinais provenientes do solo e parâmetros que reflitam os fatores climáticos e antrópicos, causadores de desestabilizações e deslizamentos, torna-se possível utilizar estes dados combinados em modelos de avaliação de risco para realizar a Predição de Deslizamentos. No Contexto Brasileiro, existe uma forte relação entre chuvas intensas e deslizamentos de encostas, devido aos fenômenos de escoamento de águas infiltradas no solo e na erosão decorrente, sendo, portanto, o monitoramento preditivo das primeiras camadas do solo um importante recurso para a detecção das áreas de eminente risco de deslizamento. Diversas abordagens para a monitoração dos solos foram apresentadas internacionalmente, sendo estas abordagens baseadas em diversas tecnologias, como exemplos podem ser citadas as técnicas de ondas acústicas no solo, detectores de umidade relativa e pluviometria seletiva. Essas abordagens podem tirar proveito do recente paradigma de Redes Sensores, baseados em dispositivos computacionais móveis de baixo consumo, movidos a baterias, que podem formar redes de trocas de dados baseadas em redes sem fio, permitindo a conexão de diversos sensores de solo, espalhados ao longo das encostas, formando um sistema de coleta destes dados de sensores em tempo real para posterior processamento e avaliação de riscos. Frente ao exposto, este trabalho propõe um sistema de monitoramento baseado em rede sensores, capaz de estimar o risco eminente de deslizamento. O sistema proposto considerou quatro dimensões do problema de desenvolvimento e prototipação do sistema de monitoramento: (1) Proposição de um Ambiente de Simulação Física, a partir da criação de um ambiente de testes em laboratório utilizando escala reduzida; (2) Reconhecimento tecnológico e refinamento de propostas de sistemas pré-existentes, que tenham a mesma finalidade, já descritos na literatura, sejam eles projetos acadêmicos ou sistemas já comercialmente disponíveis; (3) Desenvolvimento de um Sensor Inteligente Multiparamétrico; (5) desenvolvimento de uma Rede de Monitoramento para coleta de dados vindos da encosta e processamento local. Este trabalho apresenta, como contribuição técnico-científica principal, um ambiente de simulação e monitoração, sendo este ambiente relevante para estudos das dinâmicas dos deslizamentos, bem como para a prototipação de redes de monitoração para aplicações em ambientes reais, para geração de informação sobre os riscos de deslizamento, uteis para as atividades de contingenciamento dos defeitos de deslizamento por parte da Defesa Civil. / Landslides occur around the world, in various conditions of weather and terrain, costing billions of dollars, causing thousands of deaths and worsening environmental, economic and political problems. A serious question associated with landslides is the disordered of human occupation - characterizing a geopolitical and economic issue. Actions to mitigate the problems arising from this phenomenon include environmental monitoring of the areas of greatest susceptibility for managing the higher risk population. The monitoring processes consist of recognizing soil dynamics and climatic factors, responsible for causing destabilization and landslides. In the Brazilian context, there is a strong relationship between heavy rains and landslides, since the phenomenon of runoff water infiltrated the soil and produces erosion. Therefore, a predictive monitoring of the first soil layers is an important feature for detecting areas of imminent risk of slippage. Several approaches for monitoring were presented internationally, they are based on different technologies, such as acoustic waves in the soil; detectors of relative humidity and rainfall selective analysis. All these approaches are anchored in the paradigm of remote sensing and smartsensor networks. Based on that, this paper proposes a model to estimate the imminence of of landslides risk. The proposed model is built on four pillars: (i) proposing a physics simulation environment, from the creation of a laboratory scale test environments, (ii) recognizing the technology and refinement of pre-existing models, (iv) developing of multiparametric smart sensor and (v) developing of a peer-to-peer network of sensors. This study aggregates to the scientific and technical contribution a framework for monitoring, useful for studying of landslides dynamics. Such framework is crucial for prototyping monitoring networks to be used by civil defense.

De nombreuses applications industrielles mettent en jeu des fluides complexes qui possèdent souvent un seuil d'écoulement leur permettant de résister à des efforts finis sans s'écouler. Par ailleurs, ces fluides peuvent glisser aux parois lorsque les conditions interfaciales sont favorables. Toutes ces propriétés influencent leurs écoulements autour d'obstacles. Cette thèse se propose de comprendre ces écoulements dans le domaine où les vitesses d'écoulement sont telles que les effets inertiels peuvent être négligés devant les effets visqueux eux-mêmes faibles par rapport aux effets plastiques. Elle analyse l'influence de la vitesse et du glissement sur la force de traînée et les champs cinématiques générés par l'écoulement très lent et en régime permanent d'un fluide à seuil autour d'obstacles aux surfaces adhérentes ou glissantes. Les géométries considérées sont le disque, la sphère, le cône et la plaque plane. Le fluide utilisé a un comportement élasto-viscoplastique pouvant être décrit par les modèles de Herschel-Bulkley et de Hooke. Ce comportement a été caractérisé en volume et en présence de glissement par des mesures rhéométriques. Le nombre adimensionnel clé de l'étude est le nombre d'Oldroyd, ratio entre les effets plastiques et les effets visqueux, compris ici entre 10 et 200. Les mesures de forces de traînée ont montré qu'indépendamment de l'obstacle et des conditions interfaciales, le coefficient de traînée diminue avec le nombre d'Oldroyd et tend vers une valeur asymptotique. Cette valeur montre qu'au-delà d'un certain nombre d'Oldroyd, ce coefficient n'est plus gouverné par la vitesse mais dépend uniquement du seuil et de la surface caractéristique de l'obstacle. Elle permet de calculer un critère de stabilité pour lequel l'objet est maintenu en suspension. Les champs cinématiques déterminés par PIV ont permis de caractériser la forme et l'étendue des zones rigides et cisaillées. Les mesures de forces de traînée et de champs cinématiques ont permis de quantifier la contribution des contraintes normales et tangentielles dans la force de traînée totale. La présence de glissement aux parois de l'obstacle diminue significativement le coefficient de traînée et modifie la morphologie de l'écoulement en réduisant l'étendue des zones cisaillées. Une simulation numérique a été menée dans le cas de la plaque plane avec un modèle élasto-viscoplastique et un code à éléments finis avec points d'intégration Lagrangiens. / Many industrial processes include numerous complex fluids often presenting a yield stress. Those fluids can also slip when interfacial conditions are favorable. All these properties affect their flows around obstacles. This thesis aims to understand such flows in a domain where the flow velocities are so low that inertia effects can be neglected compared to viscous effects which are substantially low compared to plastic effects. It analyzes the influence of the velocity and the slip on the drag force and the kinematic fields of the creeping flow of a yield stress fluid around obstacles either with adhesive or slippery wall. The flow is analyzed in steady regime. The considered geometries are the disc, the sphere, the cone and the flat plate. The fluid used has an elasto-viscoplastic behavior which is modelled by the Herschel-Bulkley and Hooke models. This behavior has been characterized by rheometrical tests performed with adherence and slip conditions. The main non-dimensional number is the Oldroyd number, i.e. the ratio between plastic and viscous effects, which ranges from 10 to 200. The drag forces measurements have shown that regardless of the obstacle and the interfacial conditions, the drag coefficient decreases with the Oldroyd number before tending towards to an asymptotical value. This asymptotical value highlights that for high Oldroyd numbers the drag coefficient is no longer governed by the velocity but depends only on the yield stress and the characteristic section of the obstacle. A stability criterion for which the obstacle is held in suspension has been calculated from it. The kinematic fields determined by PIV have enabled to characterize the shape and the extent of the sheared and static regions. The drag forces and the kinematic fields measurements have enabled to quantify the contribution of the normal and tangential stresses in the total drag force. The wall slip significantly reduces the drag coefficient and also reduces the extent of the sheared zones. A numerical simulation has been performed with an elasto-viscoplastic model by means of a code using finite elements method with Lagrangian integration points in the case of an adhesive flat plane.