Cette thèse vise à développer une méthode pour la justification des fondations superficielles sous charge sismique dans le cadre du nouveau zonage sismique de la France, entré en vigueur en 2011 et des justifications post Fukushima. Elle s’inscrit dans le cadre d’un contrat de recherche entre l’IFSTTAR et EDF CEIDRE.Un modèle basé sur le concept de macroélément est développé pour étudier l’interaction sol-structure (ISS) en prenant en compte les différentes non linéarités. Sa formulation se base sur la théorie de l’élastoplasticité et s’inspire des normes en vigueur (Eurocodes 7 et 8) et. Les différents paramètres sont définis à partir d’essais au laboratoire ou in situ, ou à partir de simulations numériques en conditions statiques. Les coûts de calcul sont réduits du fait que les non linéarités liées à l’interaction sol-structure sont concentrés en des points particuliers du modèle de calcul. L’avantage du macroélément réside dans une formulation en efforts et déplacements, ce qui facilite son utilisation pour la justification des fondations (capacité portante, glissement, décollement, tassements, translations, distorsions et rotations).Le macroélément est implémenté dans le code par éléments finis CESAR LCPC et permet de simuler le comportement statique et sismique d’une fondation superficielle. Trois approches pour la modélisation de la radiation des ondes sismiques dans le sol sont comparées en considérant des chargements statiques et sismiques.Ensuite, des études paramétriques sont réalisées sur une structure en mettant en jeu plusieurs signaux réels. L’influence des différents paramètres de nocivité sur le comportement de la structure est étudiée.Le comportement statique et sismique d’un ouvrage réel est aussi analysé. Il s’agit d’un bâtiment fondé sur un radier reposant sur un sol stratifié. L’aléa sismique est défini par 5 accélérogrames d’accélération maximale égale à 0.4g. Des justifications normatives sont menées en se basant sur les résultats des différentes simulations réalisées / This PhD work concerns the elaboration of a method to verify the seismic sustainability of shallow foundations considering 2011 seismic zoning of France. It is a part of a research contract between EDF CEIDRE and IFSTTAR.To this end, a macroelement based model is developed in order to assess nonlinear soil structure interaction. The elastoplastic formulation of the macroelement constitutive model is compliant with the classical plasticity theory. The formulations for the plastic mechanisms are inspired from the applied standard (Eurocodes 7 & 8). The rate dependent response and the effects of the embedment and the soil inertia efforts are taken into account. The parameters for the constitutive model are defined from laboratory or field tests, or calibrated from static finite element method simulations. The calculation cost is significantly reduced due to the simplified modelling of the soil and its non linearities. Another advantage is that the macroelement based tool is formulated in terms of generalized variables (forces and displacements): this promotes its application in the verification of the sustainability of shallow foundations (bearing capacity, sliding, overturning, settlements, translations, rotations and distortions).The macroelement is implemented in the Finite Element software CESAR LCPC. It allows to simulate the static and the seismic behaviour of a shallow foundation. Three alternative approaches to assess SSI through this model are possible. These alternative approaches are explained and tested under static and seismic load.Then, it is used to perform parametric studies involving various input motions derived from earthquake recordings. The seismic response of a simple structure is studied with respect to the input motion key parameters.Finally, the static and seismic behaviour of a real structure is analysed. The structure is founded on a large raft foundation laying on a multi-layered soil. The seismic hazard is defined by five 0.4 g-PGA accelerograms. Verification to the applied standards is performed on the base of the simulation results, considering many features of the seismic behaviour

Southern Vancouver Island, situated on Canada’s West Coast, is exposed to many natural and human-made threats due to its physical geography and demography. Perceptions of these disaster risks and of seismic hazard, in particular, were surveyed through locally-administered questionnaires conducted with 105 members of the general public and 13 emergency managers living and working on southern Vancouver Island, specifically in the Cowichan Valley Regional District (CVRD) and the Capital Regional District (CRD). Perhaps the greatest risk to the region, and that, which is perceived by both the general public and practitioners as the greatest risk, is low frequency, high consequence earthquake events. The region is exposed to earthquakes from many sources, but has not experienced a damaging quake in several decades, begging questions as to whether residents consider earthquake a prominent threat and whether they have an accurate appreciation for the earthquake hazard (likelihood) in the region. While researchers have scientifically quantified the earthquake hazard in the region for over 50 years, only in the past 10 years has this hazard information been presented in a format that is comprehensible by the general public. In order for individuals and communities to make informed decisions, this information must ultimately reach the public and be interpretable and actionable. This research describes and analyzes disaster risk and seismic hazard perception on Southern Vancouver Island, and identifies whether there are gaps in communication between the scientists who create the knowledge, the emergency managers who disseminate the information, and the general public who ultimately needs to act on the information to increase their resilience. Results reveal that earthquakes are perceived as the highest disaster risk among both the general public and emergency managers on southern Vancouver Island, and that a large majority of participants know that their community is at risk from an earthquake. In addition, while emergency managers consider mostly natural threats to be significant risks, the general public more commonly identify human-made intentional threats as significant risks. The study also found that gender and location influence how individuals prefer to receive hazard information. In addition, household income and time spent living on Vancouver Island are key variables for how likely members of the general public are to be prepared. Findings suggest that while both emergency managers and the general public overestimate the earthquake hazard on southern Vancouver Island, on average emergency managers perceive the earthquake hazard to be greater than the general public does. Interestingly, general public respondents in the CVRD perceive seismic hazard to be higher than respondents in the CRD, while the calculated hazard is actually higher in the CRD. In addition, emergency managers underestimate residents’ perceptions of earthquake hazard. In other words, they feel that the public underestimates the hazard when actually both emergency managers and the general public overestimate it. These misperceptions have implications for future seismic hazard and disaster risk communication. Prior to this study, disaster risk perception has not been explored in detail in this region, and while limitations to this research are outlined, the study provides a useful descriptive analysis and baseline information for emergency managers and academic researchers to build upon. The findings of this research have specific relevance for emergency managers to inform their public education and outreach efforts around preparation, response and resilience to disasters on southern Vancouver Island. / Graduate / 2018-09-08

Les séismes sont connus comme des catastrophes naturelles destructrices et meurtrières. Particulièrement dans les régions montagneuses, les effets des séismes sont encore beaucoup plus aggravés à cause des effets de site topographiques. La présence d'une pente est à l'origine d'une amplification du signal sismique notamment dans le voisinage de la crête. De nombreux séismes anciens tels que le séisme de Lambesc (1909, Ms=6.2) qui a conduit à la destruction du village de Rognes (Bouches-du-Rhône, France), ou plus récemment le séisme d'Athènes en Grèce (1999, Ms=5.9) qui a endommagé la ville d'Adames ainsi que les séismes de Chichi à Taiwan (1999, Mw=7.6), du Salvador (2001, Mw=7.6) et du Sichuan (2008, Mw=7.9) responsables de très nombreux glissements de terrain particulièrement catastrophiques sont des exemples représentatifs. Les investigations post-sismiques ont montré une contribution importante des effets de site topographiques au bilan des dommages humains et matériels. Dans le but d'améliorer les connaissances de ce phénomène, de nombreuses simulations numériques ont été réalisées sur des modèles de versant isolés en utilisant le logiciel FLAC 2D (Itasca). Les résultats obtenus ont été analysés en considérant plusieurs critères comme les facteurs d'amplification, les surfaces et les dimensions des zones d'amplification ainsi que la distribution spatiale de ces zones dans le massif de versant. Des études paramétriques ont permis de mettre en évidence le rôle principal de la fréquence adimensionnelle, rapport de la hauteur du versant à la longueur d'onde du signal sismique, dans l'évaluation des effets de site topographiques. Ces résultats montrent également que la pente est le deuxième paramètre important, suivie du coefficient de Poisson et de la géométrie de la crête et du pied de la pente.Ces résultats numériques ont également permis de définir des relations empiriques, nommées ANS, qui permettent d'estimer les effets de site topographiques selon les différents critères d'interprétation. Ces formules sont adaptées pour les signaux sismiques avec une bande de fréquences prédominantes relativement étroite. Pour les autres cas, la Méthode de Décomposition des ondes (MD) a été développé dans ce travail. Cette méthode est basée sur la décomposition du signal complexe multi-fréquentiel en plusieurs ondes mono-fréquentielles par transformée de Fourier. L'effet du signal complexe est alors évalué en faisant une combinaison des effets individuels de chaque onde élémentaire. Ces approches développées dans ce travail (ANS et MD) permettent d'évaluer les effets de site topographiques, en tenant compte de plusieurs paramètres géomorphologiques et sismiques du massif de versant ainsi que du contenu fréquentiel du signal sismique, sans avoir recours à des simulations numériques. / Earthquakes are known as destructive and murderous natural catastrophe. Particularly in the mountainous regions, the effects of earthquakes are still much aggravated due to the topographic site effects. The presence of a slope causes an amplification of the seismic signal, particularly in the vicinity of the crest. Numerous earthquakes in the past such as the 1909 Lambesc earthquake (Ms=6.2) which led to the destruction of the Rognes village (Bouches-du-Rhône, France), or more recently the 1999 Athens, Greece earthquake (Ms=5.9) which damaged the Adames city as well as the 1999 Chichi, Taiwan earthquake (MW=7.6), the 2001 El Salvador earthquake (MW=7.6) and the 2008 Sichuan earthquake (MW=7.9) responsible for numerous catastrophic landslides are representative examples. Post-seismic investigations demonstrated a significant contribution of topographic site effects on the human and material damage assessment.In order to improve the knowledge of this phenomenon, numerous numerical simulations were performed on the step-like slope models by using the FLAC 2D software (Itasca). The obtained results were analyzed by considering various criteria such as amplification factors, dimensions and area of amplification zones as well as spatial distribution of these zones inside the slope mass. The parametric analyses allow underlining the principal role of the dimensionless frequency, ratio of the slope height to the wavelength of the seismic signal, in the evaluation of topographic site effects. These results also show that the slope angle is the second important parameter, followed by the Poisson's ratio and the geometry of the crest and of the toe of slope.These numerical results allow pointing out empirical equations, called ANS, which can be used to estimate the topographic site effects according to different interpretation criteria. These formulas are suitable for seismic signals with a relatively narrow band of predominant frequencies. For other cases, the method concerning decomposition of seismic incident wave (MD) was developed in this work. This method is based on the decomposition of the complex multi-frequency seismic signal into multiple mono-frequency waves by using Fourier transform. The effect of the complex signal is then evaluated through a combination of the effects of elementary waves. The approaches developed in this work (ANS and MD) allow evaluating the topographic site effects, by taking into account geomorphologic and seismic parameters of the slope as well as the frequency content of the seismic signal, without recourse to numerical simulations.

Background After the 2010 earthquake in Haiti, there was a significant need for basic services such as health, water, food, sanitation, school, protection and security in the largest camp in Port-au-Prince, Park Jean Marie Vincent (PJMV). PJMV IDP camp was located in the commune of Cité Soleil; a slum in Haiti labeled as a red zone and widely regarded as the most insecure place on earth. As a result, the camp residents were left to live on their own contradicting the humanitarian principle of humanity and impartiality. Strong solidarity developed amongst camp residents leading them to organize themselves in order to decrease structural violence. Zanmi Lasante (ZL), a healthcare and human rights organization that works with poorest and most vulnerable communities in Central Plateau, would cross the red zone to accompany the camp residents by providing training, materials, and resources to set up aid activities. Using a qualitative methodology, this study will describe the activities ZL completed and present the outcomes of those activities. This study will argue that the ZL accompaniment helped to decrease structural violence and chaos and allowed the camp residents to persevere. Methods This study is based on a personal story and experience of the researcher in PJMV IDP camp after the 2010 Haitian earthquake. We collected data from semi-structured interviews with 5 ZL staff, 7 camp leaders, and 5 camp residents. The researcher conducted a narrative analysis to recreate a collective memory from four viewpoints: 1) Zanmi Lasante staff; 2) camp leaders; 3) IDP camp residents and 4) the researcher. The researcher used processual methods of qualitative research to identify themes and exemplar narratives to compare and contrast these multiple viewpoints. Results The interviews offered multiple viewpoints on the activities in the camp both before and during the time ZL was active. Activities included creating and staffing a health clinic, training community health workers, establishing a nutrition center, ensuring HIV-AIDS care, and launching a response to the cholera outbreak. In addition, ZL conducted other kinds of activities that put health in the social context, including building a water purification system, establishing a tent village, creating a school program, launching an initiative to protect women from sexual violence, and advocating for food and sanitation. The researcher finds that those additional activities generated good outcomes such as health, security, job creation, capacity building, community engagement and participation, and community empowerment. ZL used a collaborative approach, integrating accompaniment into all activities by working with local residents, leaders and other organizations. This accompaniment decreased structural violence and helped camp residents to be more self-sufficient. The study also explores the challenges of accompaniment as responsibilities for these activities were shifted from ZL to the camp residents and local leaders. Conclusions The goal of this study is to describe the activities conducted by ZL in PJMV from January 2010 to January 2012 and how the approach of offering aid using the accompaniment model impacted the social context in the camp. The researcher recommends that humanitarian aid from within and beyond a disaster affected community be geared toward supporting and partnering with local communities and local organizations. In this way, humanitarian aid will strengthen local communities in a way that may be sustained once these organizations leave.

Dans le cadre des études relatives à la sûreté sismique des installations industrielles, on est amené à se préoccuper de la stabilité de structures libres (des équipements, des containers, des fûts. . . ) posées à même le sol. De nombreuses méthodes ont permis d’établir des critères de sûreté réputés conservatifs, sans qu’il soit besoin de représenter finement le comportement dynamique de l’objet. Dans le cadre de cette thèse, on a cherché à analyser la capacité de prédiction par des modèles numériques du mouvement de corps rigides libres soumis à des séismes impliquant impacts et glissements. Pour cela, on s’est appuyé sur deux campagnes expérimentales qui ont été menées au laboratoire EMSI du CEA/Saclay sur des blocs parallélépipédiques en acier, élancés et disposant de 4 appuis non ponctuels usinés avec des tolérances standards. Dans un premier temps, des essais de lâcher (bloc immobile en appuis sur deux pieds, puis lâché sans source d’excitation extérieure), souvent analysés dans la littérature comme un mouvement plan, ont fait apparaître un mouvement 3D reproductible dans les premiers instants consécutifs au lâcher. L’analyse fine de ce mouvement a permis, d’une part, de conclure qu’il était dû à des défauts de géométrie des pieds et, d’autre part, d’élaborer un modèle numérique représentatif incluant ces défauts. Dans un second temps, il a été question d’étudier l’aptitude du modèle numérique à représenter le comportement dynamique au cours du temps d’un bloc rigide élancé non idéal soumis à des excitations sismiques. Les blocs ont été soumis à 100 réalisations d’un processus stationnaire (essais de variabilité) puis 100 fois à la même accélération (essais de répétabilité). D’un point de vue statistique, et malgré les incertitudes expérimentales, ce travail a permis d’exhiber une bonne adéquation entre les résultats des modèles numériques et les résultats expérimentaux. En outre, il a permis de quantifier la durée au-delà de laquelle une prédiction du comportement ne peut plus être considérée comme pertinente. Pour finir, on s’est attaché à appliquer des outils classiques de fiabilité au problème de bloc rigide soumis à des séismes, ainsi que la méthode récente des Subset Simulations. / In the field of nuclear safety, the stability of free standing structures like containers, barrels or electronical devices is considered to be an important matter. Until now, the literature written on the subject presents some stability criteria known to be conservative without needing to represent in detail the object behavior. This thesis attempts to analyse the capacity numerical models have to predict the behavior of blocks submitted to seismic acceleration, with impacts and friction. To this effect, two experimental campaigns were carried out in the EMSI laboratory (CEA Saclay, France) on slender massive prismatic steel blocks, with 4 machined (i.e. non-ideal) feet. First of all, release tests (the block is in an unsteady position on 2 feet, kept still with a wire, then the wire is cut and the block is released without any ground motion) are usually analysed as a plane motion. Our experiments have shown a reproducible out-of-plane (3D) motion during the first seconds of the release. A detailed analysis highlighted the fact that this 3D motion is induced by geometrical defects on the block feet, and allowed us to build an accurate numerical model of this behavior. The ability of this numerical model to match the dynamic behavior of a non-ideal rigid slender block has been questioned. In a second campaign, 4 blocks were subjected on the one hand to 100 realisations of a stationnary process, and on the other hand 100 times to the same excitation. This accounts for an analysis of the variability of two 100-samples of results obtained under two different input variability levels. From a statistical point of view, despite experimental uncertainties this article demonstrates a good agreement between numerical and experimental results. Finally, some classical tools of reliabily were applied to the rocking block problem, as well as a newer method called Subset Simulation.

In this study earthquake data is analyzed using a newly developed Migration Based Detection (MBD) algorithm (Wagner et al. 2017). A software environment suitable for manual analysis of large quantities of earthquakes (events) detected by the MBD algorithm is set up, and the MBD algorithm is applied to 13 days of seismic data from a network of 26 seismic stations in the geologically complex Hengill-area in southwest Iceland. A total of 859 event detections are produced and manually inspected. Out of these, 483 are considered true and/or uncertain, making the assessed number of false detections about 44%. A subset of 53 well defined true events are selected for event relocation using manual picking of first arrival P-waves. The relocation resulted in a mean difference of roughly 0.6 km for each coordinate in the horizontal plane and about 1.4 km in depth. Results of the study provide reference data that may aid further development of the MBD algorithm, as well as provide some insight into the performance of the MBD algorithm. The software environment tailored for analyzing events detected by the MBD algorithm may be used as a foundation for continued analysis of detected events. / I denna studie analyserades jordskalvsdata med hjälp av en nyligen utvecklad 'migration based detection'-algoritm (Wagner et al. 2017). En mjukvarumiljö skräddarsydd för manuell analys av stora kvantiteter av jordskalv detekterade av MBD-algoritmen iordningställdes, varpå MBD-algoritmen sedan applicerades på 13 dagar av seismisk data från ett nätverk av 26 seismiska stationer i det geologiskt sett komplexa Hengill-området i sydvästra Island. Totalt detekterades 859 jordskalv som genomgick manuell analys. Av dessa klassificerades 483 stycken som bekräftade eller troliga jordskalv, vilket resulterar i en uppskattad felmarginal om ca. 44 %. En delmängd om 53 väldefinierade jordskalv valdes ut för noggrannare analys av ursprungsplats och tidpunkt genom manuell plockning av P-fasankomst. Omlokaliseringen resulterade i en genomsnittlig differens om ca. 0.6 km i vardera koordinat i horisontalplanet och ca. 1.4 km i höjdled. Resultat från projektet kan användas som referensdata vid vidareutveckling av MBD-algoritmen samt ger viss insyn i prestandan hos MBD-algoritmen. Den iordningställda datormiljön kan användas som bas för vidare analys av jordskalv detekterade av MBD-algoritmen.

This is a study of how two small neighbourhoods, Mano and Mikura, recovered from the 1995 Kobe (Japan) earthquake, with a particular focus on the relationship between community vulnerability and capacity. Few studies have examined these interactions, even though vulnerability reduction is recognized to be a vital component of community recovery. Drawing from literature on disaster recovery, community development, vulnerability analysis, community capacity building and the Kobe earthquake, a community vulnerability and capacity model is elaborated from Blaikie et al.’s Pressure and Release Model (1994) to analyze the interactions. The Mano and Mikura cases are analyzed by applying this model and relating outcomes to the community’s improved safety and quality of community lives. Based on the experience of Mano, appropriate long-term community development practices as well as community capacity building efforts in the past can contribute to the reduction of overall community vulnerability in the post-disaster period, while it is recovering. On the other hand, the Mikura case suggests that even though the community experiences high physical and social vulnerability in the pre-disaster period, if the community is able to foster certain conditions, including active CBOs, adequate availability and accessibility to resources, and a collaborative working relationship with governments, the community can make progress on recovery. Although both Mano and Mikura communities achieved vulnerability reduction as well as capacity building, the long-term sustainability of the two communities remains uncertain, as issues and challenges, such as residual and newly emerging physical vulnerability, negative or slow population growth and aging, remained to create vulnerability to future disasters. The case studies reveal the interactions of community vulnerability and capacity to be highly complex and contingent on many contextual considerations. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate

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The capacity spectrum method is a very popular tool in the performance based earthquake resistant design of structures. Though it involves nonlinear static analysis, it can be used to predict the dynamic behaviour of the building under earthquake load. Since the analysis is only static and not dynamic, it is very well suited for the design offices and low end computer terminals as opposed to dynamic analysis which is very resource consuming. There are several methods/variations of methods, to perform the nonlinear static analysis, popularly known as pushover analysis and convert it to capacity spectrum. Displacement based pushover analysis, force based pushover analysis, modal pushover analysis, energy based pushover analysis etc. are some of the variations of pushover analysis. There are a few attempts to consider the change in mode shape but all the methods are silent about the change in frequency due to formation of hinges in the structure. The available codes for building design such as ATC-40 provide some guidelines for getting the capacity spectrum but are not yet developed for proper ductility consideration while converting the pushover curve to capacity spectrum. The present study tries to address the above issues while proposing a new energy based approach to draw capacity spectrum. The chapter 1 introduces the concept of pushover analysis and capacity spectrum concepts. Different approaches to get these curves, their theoretical background, variations and limitations are discussed as a quick review. Chapter 2 is about the review of literature present on these topics. It is found that most of the studies have been carried out in the past on the framed buildings regarding the pushover analysis. In the last few years attempts are also made to consider the effect of torsion. Summarising the various contributions till now, it may be concluded that even in the earlier multimode pushover analysis the effect of different modes on the only static force distribution was considered. Further the spectral acceleration is obtained as a ratio of base shear and α times the weight of the building, where α is the modal mass coefficient. Only the first mode frequency could be utilized to convert the maximum displacement at the top to the spectral acceleration and the corresponding maximum potential energy (P.E.) could be used for equivalence of MDOF and SDOF. Therefore in chapter 3 which follows, the above limitation is removed as explained below. In chapter 3, the new methodology based on energy equivalence consideration is proposed step by step. For the given multistorey building, a displacement profile is applied to the building which is proportional to the effective mode shape. The effective mode shape can be the first mode shape or a combination of first few mode shapes. In the present study, two cases are considered. In the first case, the effective mode shape is considered to be the first mode shape itself whereas in the second case the effective mode shape is considered to be a linear combination of first three modes weighted by corresponding participation factors. After this, a nonlinear static analysis is performed on the structure considering the above displacement profile. Due to the above provided displacement profile, there will be yielding in the structure at a few locations. The yielded structure is again analysed for eigenvalues and mode shapes and the first three mode shapes are extracted along with their participation factors. Again the deflected structure is subjected to the deflection proportional to the effective mode shape and the analysis is continued until the collapse. The chapter also describes the details of the model used for simulation. Two kinds of simulation are performed on the model. One is considering only single mode of vibration whereas the other is considering the multiple modes (3 in this case) of vibration of the structure. Chapter 4 discusses the results of the simulations performed on the model. Single mode and multimode cases are treated and discussed separately. The proposed method is in its nascent stage and hence a lot of modification and validation work is needed to consider the method acceptable. The chapter 5 concludes the overall outcome of the present study and provides scope for the further study.