Plusieurs milliers de citoyens haïtiens se sont établis au Québec après la survenue du séisme ayant frappé Haïti le 12 janvier 2010. Beaucoup d’entre eux ont été parrainés au Québec par leur famille. L’immigration au Canada en provenance d’Haïti a débuté à la fin des années 1950 en se concentrant plus particulièrement à Montréal. Le contexte politique, social et économique en Haïti est souvent cité dans la littérature pour expliquer le départ des Haïtiens et leur installation au Québec où la « communauté haïtienne » est estimée à environ 120 000 personnes. Nous avons mené une recherche qualitative exploratoire afin de mieux comprendre la situation de nouveaux arrivants haïtiens établis à Montréal suite au séisme. Pour cela, nous nous sommes inspirés des notions d'expérience (Dubet, 1994) et de représentation (Hall, 1997). Entre novembre 2012 et janvier 2013, nous avons réalisé neuf entrevues dont sept avec des femmes et deux avec des hommes âgés de 23 à 60 ans. Les résultats suggèrent que les participants accordent beaucoup d'importance à la vie dans le pays d'origine avant la migration dans l'élaboration de leurs expériences. L'expérience actuelle « ici » est élaborée en comparaison à l'expérience passée « là-bas ». Les participants insistent également sur l'importance du réseau familial lors du processus migratoire, à la fois dans les démarches d'émigration et dans l'accompagnement au pays d'accueil. Des émotions douloureuses ont été exprimées face à la séparation familiale, vécue comme une des conséquences de la migration. Les participants ont tous entamé des démarches d'insertion en emploi mais ils ont fait face à des difficultés dont la plupart d'entre eux qualifient de « structurelles » et que certains qualifient de difficultés « personnelles ». Enfin, les résultats indiquent que les participants sont porteurs d'un imaginaire migratoire qui s'exprime par des aspirations et des attentes par rapport à la société d'accueil et qui rend compte d’une tension entre ces aspirations et les expériences vécues. / Thousands of Haitian citizens have settled in Quebec after the occurrence of the earthquake that struck Haiti on January 12, 2010. Many of them have been sponsored in Quebec by their families. Immigration to Canada from Haiti began during the late 1950s focusing more particularly in Montreal. The political, social and economic context in Haiti is often cited in the literature to explain the departure of Haitians and their installation in Quebec where the 'Haitian community' is estimated at about 120,000 people. We conducted an exploratory qualitative research to better understand the situation of Haitian newcomers established in Montreal following the earthquake. To do this, we inspired by notions of experience (Dubet, 1994) and representation (Hall, 1997). Between November 2012 and January 2013, we carried out nine interviews with seven women and two men aged from 23 to 60 years. The results suggest that participants place great importance to life in the country of origin prior to migration in the development of their experiences. Experience current "here" is developed in comparison to experience past 'out there '. Participants also emphasized the importance of the family network when the migration process, both in the processes of emigration and in the accompaniment to the host country. Painful emotions were expressed against the separation family, lived as one of the consequences of the migration. Participants began efforts to integrate employment but they were faced with difficulties that most of them describe as "structural" and that some "personal". Finally, the results indicate that participants are carriers of an imaginary migration which is expressed by aspirations and expectations compared to the host society and which reflects a tension between these aspirations and experiences.

No description available.

The 2010 earthquake in Haiti, which killed an estimated 316,000 people, offered many lessons in mass-fatality management (MFM). The dissertation defined MFM in seeking information and in recovery, preservation, identification, and disposition of human remains. Specifically, it examined how mass fatalities were managed in Haiti, how affected individuals sought information about fatalities, and what needs motivated them. Data from 28 in-depth, partially structured interviews, conducted during two field visits ending 21 weeks after the earthquake, were included in a case study. The data analysis revealed the MFM was severely inadequate. One interviewee, a senior UN official, stated, "There was no fatality management." The analysis also indicated a need to learn whereabouts of the deceased motivated individuals to visit spots the deceased were last seen at. It sought to illumine information-seeking practices, as discussed in the works of J. David Johnson and others, by developing a new model of information flow in MFM. In addition, it reaffirmed Donald Case and Thomas Wilson's theoretical proposition – that need guides any seeking of information – in the case of Haiti. Finally, it produced recommendations regarding future directions in MFM for emergency managers and information scientists, including possible use of unidentified body parts in organ transplants. Overall, the dissertation, which was supported by two grants of the National Science Foundation, attempted to add to relatively scanty literature in information seeking in MFM.

This thesis examines Late Minoan Settlements in Crete that were destroyed or abandoned due to the consequences of the Santorini volcano eruption. A summary of geological history of Crete, Thera and the surrounding area is given in the first part. The next chapter sums up the research in the fields of relative and mainly absolute chronology, of which scientists have not yet been able to provide a convincing calendar date for the eruption of the volcano nor a possible fixed absolute chronology of the general Later Bronze Age not only in the Aegean. The development of the Santorini Volcano eruption in the Late Minoan IA period (LM IA) is described. According to the research, this eruption must have caused earthquakes and tsunamis. The possible impact on the near island of Crete, its inhabitants and settlements, mainly in the coastal area of north-northeast part of the island, is also discussed.

Approved for public release, distribution is unlimited / This thesis examines the Greek-Turkish ongoing rapprochement. This latest rapprochement effort followed closely two devastating earthquakes that hit Greece and Turkey consequently in 1999. The two nations sent official and private (NGO) relief help, including search and rescue teams, to the areas struck. This study examines whether there are tangible shifts in the policies of the two countries that could sustain the rapprochement, or whether the adjustment is superficial and could collapse as soon as any controversial issue(s) arise between the two nations. It approaches the question with the clarity provided by hindsight, employing three past case studies of similar endeavors of the two countries. By examining the three past cases as well as considering all empirical evidence for the present rapprochement, this thesis concludes that there is tangible evidence of a shift in Greek foreign policy toward Turkey, whereas with respect to Turkish policy, there exist encouraging rhetoric and gestures but no evidence of adequate reciprocity towards Greece on the political level. Finally, the thesis provides policy recommendations for both sides. / Commander, Hellenic Navy

"Maintaining an efficient and reliable infrastructure requires continuous monitoring and control. In order to accomplish these tasks, algorithms are needed to process large sets of data and for modeling based on these processed data sets. For this reason, computationally efficient and accurate modeling algorithms along with data compression techniques and optimal yet practical control methods are in demand. These tools can help model structures and improve their performance. In this thesis, these two aspects are addressed separately. A principal component analysis based adaptive neuro-fuzzy inference system is proposed for fast and accurate modeling of time-dependent behavior of a structure integrated with a smart damper. Since a smart damper can only dissipate energy from structures, a challenge is to evaluate the dissipativity of optimal control methods for smart dampers to decide if the optimal controller can be realized using the smart damper. Therefore, a generalized deterministic definition for dissipativity is proposed and a commonly used controller, LQR is proved to be dissipative. Examples are provided to illustrate the effectiveness of the proposed modeling algorithm and evaluating the dissipativity of LQR control method. These examples illustrate the effectiveness of the proposed modeling algorithm and dissipativity of LQR controller."

The recent 2011 Tōhoku earthquake and tsunami served as a stark reminder of the destructive capabilities of such combined events. Civil Engineers are increasingly tasked with protecting coastal populations and infrastructure against more severe multi-hazard events. Whilst the protective measures must be robust, their deployment over long stretches of coastline necessitates an economical and environmentally friendly design. The dual row retaining wall concept, which features two parallel sheet pile walls with a sand infill between them and tie rods connecting the wall heads, is potentially an efficient and resilient system in the face of both earthquake and tsunami loading. Optimal use of the soil's strength and stiffness as part of the structural system is an elegant geotechnical solution which could also be applied to harbours or elevated roads. However, both the static equilibrium and dynamic response of these types of constructions are not well understood and raise many academic and practical challenges. A combination of centrifuge and numerical modelling was utilised to investigate the problem. Studying the mechanics of the walls in dry sand from the soil stresses to the system displacements revealed the complex nature of the soil structure interaction. Increased wall flexibility can allow more utilisation of the soil's plastic capacity without necessarily increasing the total displacements. Recognising the dynamically varying vertical effective stresses promotes a purer understanding of the earth pressures mobilised around the walls and may encourage a move away from historically used dynamic earth pressure coefficients. In a similar vein, the proposed modified Winkler method can form the basis of an efficient preliminary design tool for practice with a reduced disconnect between the wall movements and mobilised soil stresses. When founded in liquefiable soil and subjected to harmonic base motion, the dual row walls were resilient to catastrophic collapse and only accrued deformation in a ratcheting fashion. The experiments and numerical simulations highlighted the importance of relative suction between the walls, shear-induced dilation and regained strength outside the walls and partial drainage in the co-seismic period. The use of surrogate modelling to automatically optimise parameter selection for the advanced constitutive model was successfully explored. Ultimately, focussing on the mechanics of the dual row walls has helped further the academic and practical understanding of these complex but life-saving systems.

Chemical weathering of silicate rock consumes atmospheric CO2 and supplies the oceans with cations, thereby controlling both seawater chemistry and climate. The rate of CO2 consumption is closely linked to the rate of CO2 outgassing from the planetary interior, providing a negative feedback loop essential to maintaining an equable climate on Earth. Reconstruction of past global temperatures indicates that a pronounced episode of global cooling began ~50 million years ago, coincident with the collision of India and Asia, and the subsequent exhumation of the Himalayas and Tibet. This has drawn attention to the possible links between exhumation, erosion, changes in silicate weathering rates, and climate. However, many of the present-day weathering processes operating on the continents remain debated and poorly constrained, hampering our interpretations of marine geochemical archives and past climatic shifts. To constrain the controls on silicate weathering, this thesis investigates the lithium (Li) isotopic composition of river waters, suspended sediments and bed load sediments in the Alaknanda river basin, forming the headwaters of the Ganges. Due to the large fractionation of Li isotopes in the Earth’s surface environment, Li is sensitive to small changes in silicate weathering processes. As a consequence of the pronounced gradients in climate (rainfall and temperature) and erosion across the basin, the river waters show large variations in their Li isotopic composition (δ7Li), ranging from +7.4 to +35.4‰, covering much of the observed global variation. This allows a detailed investigation of the controls on Li isotope fractionation, and by extension silicate weathering. The Li isotopic composition is modelled using a one-dimensional reactive transport model. The model incorporates the continuous input of Li from rock dissolution, removal due to secondary mineral formation, and hydrology along subsurface flow paths. Modelling shows that the Li isotopic variations can be described by two dimensionless variables; (1) the Damköhler number, ND, which relates the silicate dissolution rate to the fluid transit time, and (2) the net partition coefficient of Li during weathering, kp, describing the partitioning of Li between secondary clay minerals and water, which is primarily controlled by the stoichiometry of the weathering reactions. The derived values of the controlling parameters ND and kp, are investigated over a range of climatic conditions and on a seasonal basis, shedding light onto variations in the silicate weathering cycle. In a kinetically limited weathering regime such as the Himalayan Mountains, both climate and erosion exert critical controls the weathering intensity (the fraction of eroded rock which is dissolved) and the weathering progression (which minerals that are being weathered), and consequently the fractionation of Li isotopes and silicate weathering in general. Modelling of the Li isotopic composition provides an independent estimate of the parameters which control silicate weathering. These estimates are then used to constrain variables such as subsurface fluid flux, silicate dissolution rates, fluid transit times and the fraction of rock which is weathered to form secondary clay minerals. The simple one-dimensional reactive transport model therefore provides a powerful tool to investigate the minimum controls on silicate weathering on the continents.

Atualmente as estruturas estão sendo avaliadas para um maior número de ações em relação há algumas décadas. Esta melhoria ao longo da fase de concepção é dada devido ao fato de que está se tornando mais competitivo o fornecimento de estruturas leves e esbeltas, sendo solicitados, cada vez mais, projetos com menor custo de implantação. Devido a isto, é necessário avaliar as estruturas não apenas sujeitas a cargas estáticas, mas também a carregamentos dinâmicos. As ações dinâmicas que atuam sobre uma estrutura podem ser muito mais prejudiciais do que as estáticas quando não são bem consideradas e dimensionadas. Ações dinâmicas podem ser provenientes de tremores de terra, vento, equipamentos em funcionamento, deslocamento de pessoas, veículos em movimento, motores desbalanceados, entre outras fontes, o que pode causar vibrações na estrutura, podendo levar a mesma ao colapso. A fim de controlar e reduzir as amplitudes de vibração, entre outras alternativas é possível a instalação de amortecedores de massa sintonizado (AMS), que é um dispositivo de controle passivo. O AMS tem várias vantagens, tais como a grande capacidade de reduzir a amplitude de vibração, fácil instalação, baixa manutenção, baixo custo, entre outras. Para se obter a melhor relação custo-benefício, ou seja, a maior redução de amplitude aliada a um menor número de amortecedores ou a uma menor massa, a otimização dos parâmetros do AMS tornase fundamental. Neste contexto, este trabalho visa, através de simulação numérica, propor um método para otimizar parâmetros de AMSs quando estes devem ser instalados em edifícios submetidos à excitação sísmica. Inicialmente é considerado apenas um único AMS instalado no topo do edifício e em seguida também são feitas simulações com múltiplos AMSs (MAMS), e por fim são descartados os AMSs desnecessários, obtendo assim a melhor resposta da estrutura. Para tanto, uma rotina computacional é desenvolvida em MatLab usando o método de integração direta das equações de movimento de Newmark para determinar a resposta dinâmica da estrutura. Para fins de análise podem ser considerados tanto sismos reais quanto artificiais. Os acelerogramas artificias são gerados a partir do espectro proposto por Kanai e Tajimi. Primeiramente, a estrutura é analisada somente com o seu amortecimento próprio para fins comparativos e de referência. Em seguida, a otimização do ou dos AMSs é feita, na qual a função objetivo é minimizar o deslocamento máximo no topo do edifício, e as variáveis de projeto, são a relação de massas (AMS - Estrutura), rigidez e amortecimento do ou dos AMSs. Para a otimização são utilizados os algoritmos Firefly Algotithm e Backtracking Search Optimization Algorithm. De acordo com as configurações do AMS, após a otimização dos seus parâmetros são determinadas as novas respostas dinâmicas da estrutura. Finalmente, pode-se observar que o método proposto foi capaz de otimizar os parâmetros do ou dos AMSs, reduzindo consideravelmente as respostas da estrutura após a instalação do mesmo, minimizando o risco de dano e colapso do edifício. Desta forma, este trabalho mostra que é possível projetar AMS e MAMS de forma econômica e eficaz. / Currently, structures are being evaluated for a greater number of actions when compared to a few decades ago. This improvement in designing stage is happening because projects providing lightweight and slender structures, with lower implantation costs, are being more requested. Thus, evaluating structures not only subjected to static loads, but also to dynamic loads has become necessary. Dynamic loads acting on a structure are more damaging than static loads, if they are not well considered and dimensioned. Dynamic loads could occur from earthquakes, wind, equipment, movement of people or vehicles, among other sources, which cause vibrations in structures and may lead to a collapse. Tuned mass damper (TMD), a passive control device, can be installed as an alternative to reduce vibration amplitudes. TMD has several advantages, such as large capacity to reduce amplitude of vibration, easy installation, low maintenance, low cost, among others. Optimizing TMD parameters is fundamental for obtaining best cost-benefit relation, i.e., greater amplitude reduction along with lower number of dampers or lower mass. In this context, this study aims at proposing, through numerical simulation, a method for optimizing TMD parameters when installing them on buildings under seismic excitation. Initially, a single-TMD case is considered, then simulations with multiple-TMDs (MTMDs) are run; lastly, unnecessary TMDs are discarded, obtaining the best structural response. For this purpose, a computational routine is developed on MatLab using Newmark direct integration method for equations of motion to determine the dynamic structural response. Both real and artificial earthquakes are considered for purposes of analysis. Artificial accelerograms are generated from proposed Kanai-Tajimi spectrum. First, structure is analyzed only with its own damping for comparison and reference. Second, a single or multiple-TMD optimization is carried out, in which the objective function is to minimize the maximum displacement at the top of the building, and the design variables are modal mass ratio (Structure-TMD), stiffness and damping of a single or multiple-TMD. Firefly and Backtracking Optimization algorithms are used for optimization. According to TMD settings, new dynamic structural responses are determined after optimizing parameters. Finally, the proposed method could optimize parameters of single or multiple-TMDs, considerably reducing structural responses after their installation, minimizing the risk of damage and building collapse. Thus, this study shows the possibility of designing TMDs or MTMDs both economically and effectively.

L'importance croissante de l'évaluation de la performance des structures soumis au chargement sismique souligne la nécessité d'estimer le risque de liquéfaction. Dans ce scénario extrême de la liquéfaction du sol, des conséquences dévastatrices sont observées, par exemple des tassements excessifs et des instabilités de pentes. Dans le cadre de cette thèse, la réponse dynamique et l'interaction d'un système ouvrage en terre-fondation sont étudiées, afin de déterminer quantitativement le mécanisme de ruine dû à la liquéfaction du sol de la fondation. Par ailleurs, les chargements sismiques peuvent induire dans les ouvrages en terre un mode de rupture générant des bandes de cisaillement. Une étude de sensibilité aux maillages a donc été engagée pour quantifier la dépendance des résultats de l'analyse dynamique. Par conséquent, l'utilisation d'une méthode de régularisation est évaluée au cours des analyses dynamiques. Le logiciel open-source Code_Aster, basé sur la méthode des Eléments Finis et développé par EDF R&D, est utilisé pour les simulations numériques, tandis que le comportement du sol est représenté par le modèle de comportement de l'ECP, développé à CentraleSupélec. En premier lieu, un modèle simplifié de propagation 1D des ondes SH dans une colonne de sol avec comportement hydromécanique couplé non linéaire a été simulé. L'effet des caractéristiques du signal sismique et de la perméabilité du sol sur la liquéfaction est évalué. Le signal sismique d'entrée est un élément important pour l'apparition de la liquéfaction, puisque la durée du choc principal peut conduire à de fortes non linéarités et à un état de liquéfaction étendu. En outre, quand une variation de perméabilité en fonction de l'état de liquéfaction est considérée, des changements significatifs sont observés pendant la phase de dissipation de la surpression interstitielle de l'eau et au comportement du matériau. En revanche, ces changements ne suivent pas une tendance unique. Puis, l'effet d'une méthode de régularisation avec cinématique enrichie, appelée premier gradient de dilatation, sur la propagation des ondes SH est étudié au travers d'une solution analytique. Des problèmes à la réponse dynamique du sol sont observés et discutés quand cette méthode de régularisation est appliquée. Ensuite, un modèle 2D d'un déblai est simulé et sa réponse dynamique est évaluée en conditions sèches, complètement drainées et hydromécanique couplées. Deux critères sont utilisés pour définir le début de la rupture de la structure. Le travail du second ordre est utilisé pour décrire l'instabilité locale à des instants spécifiques du mouvement sismique, tandis que l'estimation d'un facteur de sécurité locale est proposée prenant en compte la résistance résiduelle du sol. En ce qui concerne le mode de ruine, l'effet de la surpression interstitielle de l'eau est de grande importance, puisqu'un déblai stable en conditions sèches et complètement drainées, devient instable lors de l'analyse couplée à cause de la liquéfaction de la fondation. Enfin, un système digue-fondation est simulé et l'influence de la perméabilité du sol, la profondeur de la couche liquéfiable, ainsi que, les caractéristiques du séisme sur la ruine induite par la liquéfaction du sol est évaluée. Pour ce modèle de digue, le niveau de dommages est fortement lié à la fois à l'apparition de la liquéfaction dans la fondation et la dissipation de la surpression d'eau. Une surface d'effondrement circulaire est générée à l'intérieur de la couche du sol liquéfié et se propage vers la crête dans les deux côtés de la digue. Pourtant, lorsque la couche liquéfiée est située en profondeur, la digue n'est pas affectée par la liquéfaction de la fondation pour ce cas particulier de chargement. Ce travail de recherche se concentre sur une étude de cas de référence pour l'évaluation sismique des ouvrages en terre soumis à un séisme et fournit des méthodes et outils de calculs numériques performants accessibles aux ingénieurs. / The increasing importance of performance-based earthquake engineering analysis points out the necessity to assess quantitatively the risk of liquefaction. In this extreme scenario of soil liquefaction, devastating consequences are observed, e.g. excessive settlements, lateral spreading and slope instability. The present PhD thesis discusses the global dynamic response and interaction of an earth structure-foundation system, so as to determine quantitatively the collapse mechanism due to foundation’s soil liquefaction. As shear band generation is a potential earthquake-induced failure mode in such structures, the FE mesh dependency of results of dynamic analyses is thoroughly investigated and an existing regularization method is evaluated. The open-source FE software developed by EDF R&D, called Code_Aster is used for the numerical simulations, while soil behavior is represented by the ECP constitutive model, developed at CentraleSupélec. Starting from a simplified model of 1D SH wave propagation in a soil column with coupled hydromechanical nonlinear behavior, the effect of seismic hazard and soil’s permeability on liquefaction is assessed. Input ground motion is a key component for soil liquefaction apparition, as long duration of mainshock can lead to important nonlinearity and extended soil liquefaction. Moreover, when a variation of permeability as function of liquefaction state is considered, changes in the dissipation phase of excess pore water pressure and material behavior are observed, which do not follow a single trend. The effect of a regularization method with enhanced kinematics approach, called first gradient of dilation model, on 1D SH wave propagation is studied through an analytical solution. Deficiencies of the use of this regularization method are observed and discussed, e.g. spurious waves apparition in the soil’s seismic response. Next, a 2D embankment-type model is simulated and its dynamic response is evaluated in dry, fully drained and coupled hydromechanical conditions. Two criteria are used to define the onset of the structure’s collapse. The second order work is used to describe the local instability at specific instants of the ground motion, while the estimation of a local safety factor is proposed by calculating soil’s residual strength. Concerning the failure mode, the effect of excess pore water pressure is of great importance, as an otherwise stable structure-foundation system in dry and fully drained conditions becomes unstable during coupled analysis. Finally, a levee- foundation system is simulated and the influence of soil’s permeability, depth of the liquefiable layer, as well as, characteristics of input ground motion on the liquefaction-induced failure is evaluated. For the current levee model, its induced damage level (i.e. settlements and deformations) is strongly related to both liquefaction apparition and dissipation of excess pore water pressure on the foundation. A circular collapse surface is generated inside the liquefied region and extends towards the crest in both sides of the levee. Even so, when the liquefied layer is situated in depth, no effect on the levee response is found. This research work can be considered as a reference case study for seismic assessment of embankment-type structures subjected to earthquake and provides a high-performance computational framework accessible to engineers.