The dynamic behaviour of high-rise buildings has become a critical design consideration as buildings are built taller and more slender. Large wind vibrations cause an increase in the lateral wind loads, but more importantly, they can be perceived by building occupants creating levels of discomfort ranging from minor annoyance to severe motion sickness. The current techniques to address these issues include stiffening the lateral load resisting system, reducing the number of stories, or incorporating a vibration absorber at the top of the building. All of which have consequences on the overall project cost. The dynamic response of high-rise buildings is highly dependent on damping. Full-scale measurements of high-rise buildings have shown that the inherent damping decreases with height and recent in-situ measurements have shown that the majority of buildings over 250 meters have levels of damping less than 1% of critical. Studies have shown that small increases in the inherent damping can lead to vast improvement in dynamic response. A new damping system, the viscoelastic (VE) Fork Configuration Damper (FCD), has been developed at the University of Toronto to address these design challenges. The proposed FCDs are introduced in lieu of coupling beams in reinforced concrete (RC) coupled wall buildings and take advantage of the large shear deformations at these locations when the building is subjected to lateral loads. An experimental study was conducted on 5 small-scale VE dampers to characterize the VE material behaviour and 6 full-scale FCD samples in an RC coupled wall configuration (one designed for areas where low to moderate ductility is required and one with built-in ductile structural “fuse” for areas where high ductility is required). The VE material tests exhibited stable hysteretic behaviour under expected high-rise loading conditions and the full-scale tests validated the overall system performance based on the kinematic behaviour of coupled walls, wall anchorage and VE material behaviour. Analytical models were developed that capture the VE material behaviour and the FCD system performance well. An 85-storey high-rise building was studied analytically to validate the design approach and to highlight the improvements in building response resulting from the addition of FCDs.

This dissertation proposes an analysis of representative texts that portray the earthquake that hit Mexico City in 1985 as a historical event that contributed to forging new ways of interaction among the people itself, as well as between the community as a whole and its government. By examining the representations of this historically important episode in the life of the city, this project compensates for a significant omission of literary criticism—that has relegated the substantial corpus of texts about this catastrophe to brief comments or footnotes on other topics. Through analysis of testimonial chronicles, newspaper articles, political cartoons, music videos, poetry, drama, and narratives, this dissertation investigates the process through which intellectuals created discursive constructions of a new relationship between Mexican society and its government. The following pages give an account of the debate to shape the historical interpretation of the catastrophe: some texts challenged the patrimonialism institutionalized by the government bureaucracy of the PRI State, while others supported the structures in place even though they acknowledged the need for a nimbler bureaucracy. Therefore, this study is focused on texts that incorporate previous discursive traditions to propose new symbolic ways to understand the nation after the earthquake. This discussion engages texts by authors committed to diverse perspectives—such as Elena Poniatowska, Carlos Monsiváis, José Emilio Pacheco, Carlos Olmos, Enrique Serna, and Rodrigo Fresán, among others—to offer a panorama on the arguments presented on the cultural field. This dissertation considers four specific moments in the construction of the new national narrative: (1) the call for solidarity with the victims of the disaster; (2) the redefinition of the idea of civil society; (3) the debate within mass media to impose a particular meaning to both solidarity and civil society; and (4) the questioning of the main discourses related to the earthquake. This study illuminates the ways that the earthquake narratives have been deployed to challenge political inequities and injustices and to attempt political change towards a modern Mexican State.

The amount of total and relative sway of a framed or a composite (frame-shear wall) building is of utmost importance in assessing the seismic resistance of the building. Therefore, the design engineer must calculate the sway profile of the building several times during the design process. However, it is not a simple task to calculate the sway of a three-dimensional structure. Of course, computer programs can do the job, but developing the three-dimensional model becomes necessary, which is obviously tedious and time consuming. An easy to apply analytical method is developed, which enables the determination of sway profiles of framed and composite buildings subject to seismic loading. Various framed and composite three-dimensional buildings subject to lateral seismic loads are solved by SAP2000 and the proposed analytical method. The sway profiles are compared and found to be in very good agreement. In most cases, the amount of error involved is less than 5 %. The analytical method is applied to determine sway magnitudes at any desired elevation of the building, the relative sway between two consecutive floors, the slope at any desired point along the height and the curvature distribution of the building from foundation to roof level. After sway and sway-related properties are known, the requirements of the Turkish Earthquake Code can be evaluated and / or checked. By using the analytical method, the amount of shear walls necessary to satisfy Turkish Earthquake Code requirements are determined. Thus, a vital design question has been answered, which up till present time, could only be met by rough empirical guidelines. A mathematical derivation is presented to satisfy the strength requirement of a three-dimensional composite building subject to seismic loading. Thus, the occurrence of shear failure before moment failure in the building is securely avoided. A design procedure is developed to satisfy the stiffness requirement of composite buildings subject to lateral seismic loading. Some useful tools, such as executable user-friendly programs written by using &ldquo / Borland Delphi&rdquo / , have been developed to make the analysis and design easy for the engineer. A method is also developed to satisfy the ductility requirement of composite buildings subject to lateral seismic loading based on a plastic analysis. The commonly accepted sway ductility of &amp / #956 / &amp / #916 / =5 has been used and successful seismic energy dissipation is thus obtained.

Tsunamis are characterized as shallow water waves, with long periods and wavelengths. They occur by a sudden water volume displacement. Earthquake is one of the main reasons of a tsunami development. Historical data for an observation period of 3500 years starting from 1500 B.C. indicates that approximately 100 tsunamis occurred in the seas neighboring Turkey. Historical earthquake and tsunami data were collected and used to develop two artificial neural network models to forecast tsunami characteristics for future occurrences and to estimate the tsunami return period. Artificial Neural Network (ANN) is a system simulating the human brain learning and thinking behavior by experiencing measured or observed data. A set of artificial neural network is used to estimate the future earthquakes that may create a tsunami and their magnitudes. A second set is designed for the estimation of tsunami inundation with relation with the tsunami intensity, the earthquake depth and the earthquake magnitude that are predicted by the first set of neural networks. In the case study, Marmara and Aegean regions are taken into consideration for the estimation process. Return periods including the last occurred earthquake in the Turkish seas, which was the izmit (Kocaeli) Earthquake in 1999, were utilized together with the average earthquake depths calculated for Marmara and Aegean regions for the prediction of the earthquake magnitude that may create a tsunami in the stated regions for various return periods of 1-100 years starting from the year of 2004. The obtained earthquake magnitudes were used together with tsunami intensities and earthquake depth to forecast tsunami wave height at the coast. It is concluded that, Neural Networks predictions were a satisfactory first step to implement earthquake parameters such as depth and magnitude, for the average tsunami height on the shore calculations.

There is a great amount of building stock built in earthquake regions where earthquakes frequently occur. It is very probable that such buildings experience earthquakes more than once throughout their economic life. The motivation of this thesis arose from the lack of procedures to determine the change in building capacity as a result of prior earthquake damage. This study focuses on establishing a method that can be employed to determine the loss in the building capacity after experiencing an earthquake. In order to achieve this goal a number of frames were analyzed under several randomly selected earthquakes. Nonlinear time-history analyses and nonlinear static analyses were conducted to assess the prior and subsequent capacities of the frames under consideration. The structural analysis programs DRAIN-2DX and SAP2000 were employed for this purpose. The capacity curves obtained by these methods were investigated to propose a procedure by which the capacity of previously damaged structures can be determined. For time-history analyses the prior earthquake damage can be taken into account by applying the ground motion histories successively to the structure under consideration. In the case of nonlinear static analyses this was achieved by modifying the elements of the damaged structure in relation to the plastic deformation they experience. Finally a simple approximate procedure was developed using the regression analysis of the results. This procedure relies on the modification of the structure stiffness in proportion to the ductility demand the former earthquake imposes. The proposed procedures were applied to an existing 3D building to validate their applicability.

The results of an experimental investigation are presented which examine the seismic adequacy of pre-1970 reinforced concrete (RC) corner beam-column joints and the efficacy of carbon fiber-reinforced polymer (CFRP) composites for both pre- and post-earthquake retrofit of such joints. Four full-scale corner beam-column-slab subassemblages built with identical dimensions and pre-1970 reinforcement details were subjected to a reverse-cycle bidirectional displacement history consisting of alternate and simultaneous cycles in the two primary frame directions before and/or after retrofit. Two of the specimens were first subjected to severe and moderate levels of damage, respectively, then repaired by epoxy injection, and strengthened by adding a #7 reinforcing bar within the clear cover at the column inside corner and by externally bonding multiple layers of carbon fabric to form a carbon-epoxy retrofit system. Two other specimens, one of which had a significantly lower concrete compressive strength, were strengthened in their as-built condition. The CFRP scheme was improved in light of the findings as the experimental program progressed. Pre-1970 RC corner beam-column joints were found to be severely inadequate in meeting seismic demands because of column bar yielding, joint shear failure, loss of anchorage of beam bottom bars, failure of column lap-splices, and the resulting loss of stiffness and strength that dominate their behavior even at relatively low interstory drift levels. Bidirectional loading played a significant role in such response. It was shown, however, that such joints can be strengthened easily both before and after earthquake damage by using CFRP composite schemes. Regardless of the level of existing damage and concrete strength, a "rigid" joint behavior up to interstory drift ratios of at least 2.4% and joint shear strength factors ranging from 1.06 to 1.41√MPa were achieved; such shear strength factors are larger than the value of 1.00√MPa recommended for use with seismically designed, code-conforming corner beam-column joints. A ductile beam hinging mechanism was achieved and energy dissipation capacity was improved efficiently for joints with concrete strengths ranging from 26 to 34 MPa. The subassemblage with significantly low-strength concrete (15 MPa) had low overall lateral stiffness and reduced reinforcement anchorages which prevented the formation of beam hinging. In cases of such low-strength concrete, more invasive operations may be required so that the improved joint shear strength can be mobilized. It is recommended that bidirectional loading be always considered in both pre- and post-retrofit evaluation of corner joints.

La sismicité sous la mer Tyrrhénienne méridionale et le sud de l'Italie est essentiellement attribuée à la subduction de la lithosphère océanique Ionienne qui s'enfonce dans le manteau Tyrrhénien jusqu'à 500 km de profondeur. Les tomographies proposées à ce jour n'ont pas une résolution suffisante pour distinguer les différentes structures géologiques à grande profondeur, laissant donc encore de nombreuses questions ouvertes concernant la géodynamique régionale. Dans ce travail on a en développé des aspects méthodologiques qui mettent en œuvre une nouvelle technique de post-processing appelée WAM (Weighted Average Model). Cette méthode nous a permis d' obtenir des modèles de vitesse à haute résolution de la région sud Tyrrhénienne en réalisant une tomographie sismique 3D des ondes P et S. Avec WAM on a ainsi pu reconstruire la géométrie 3D du slab Ionien et proposer un nouveau scenario géodynamique pour la région basé sur de considérations pétrologiques.

Κατά την διάρκεια της ύστερης αρχαιότητας στην Β. Πελοπόννησο, ισχυροί σεισμοί έχουν πλήξει κατοικημένες περιοχές, προκαλώντας μεγάλες καταστροφές. Στην παρούσα εργασία εξετάζονται δημοσιευμένες συστηματικές ή/και σωστικές ανασκαφές, που οι ενδείξεις των ευρημάτων τους οδηγούν στο ότι συγκεκριμένες περιοχές έχουν πληγεί από σεισμούς. Πιο συγκεκριμένα, μελετήθηκαν 12 αρχαιολογικές θέσεις στην περιοχή της Β. Πελοποννήσου τη χρονική περίοδο από τον 1ο αιώνα μ.Χ έως και τον 6ο αιώνα μ.Χ. Με την παρούσα εργασία έγινε δυνατός με μεγαλύτερη ακρίβεια ο χρονικός προσδιορισμός της εκδήλωσης των σεισμικών γεγονότων σε σύγκριση με τις υπάρχουσες καταγραφές σε καταλόγους ιστορικών σεισμών ή προστέθηκαν επιπλέον σεισμικά γεγονότα ή αφαιρέθηκαν σεισμοί ανάλογα με το αν έχουν ή δεν έχουν αναγνωρισθεί στις αρχαιολογικές ανασκαφές, Συσχετίσθηκαν ρήγματα με ισχυρούς σεισμούς του παρελθόντος με βάση την γειτνίαση ή την διασπορά των καταστροφών σε αρχαιολογικές ανασκαφικές μαρτυρίες. Τέλος σύμφωνα με τα συμπεράσματα της παρούσας μελέτης, ισχυροί σεισμοί επηρέασαν την περιοχή της Β. Πελοποννήσου σε αρχαιολογικές θέσεις στον δυτικό και ανατολικό Κορινθιακό προσθέτοντας νέα στοιχειά στην χρονολόγηση και στην ένταση τους. Με βάση τα στοιχεία αυτά καταδεικνύεται ότι ο Ανατολικός Κορινθιακός παρουσιάζει συχνότερη σεισμική δραστηριότητα έναντι της δυτικής απόληξής του. / During the late antiquity in northern Peloponnesus, strong earthquakes have hit residential areas, causing considerable damage/major disasters. In the present study published systematic and / or rescue excavations are examined, whose finding evidence lead to the fact that specific regions are affected by earthquakes. More specifically, 12 archaeological sites in Northern Peloponnese have been studied from the period from the 1st century AD to the 6th century AD. In the present research the time of the occurrence of seismic activity was detected with greater precision in comparison with the existing records in the lists of historical earthquakes. Moreover, seismic activities were added or earthquakes were removed, depending on whether or not they have been identified in archeological excavations. Cracks have been associated with strong earthquakes of the past based on the vicinity or outspread of disasters in archaeological excavation evidence. Finally, according to the conclusions of this study, strong earthquakes have affected the area of North Peloponnesus, at archaeological sites in western and eastern Corinthian Gulf, adding new elements to their dating and their intensity. Based on these data it is demonstrated that the East Corinthian Gulf has more frequent seismic activity than its western part.

La variation spatiale du mouvement sismique a des effets significatifs sur la réponse dynamique des structures de génie civil de grandes dimensions. Dans la pratique courante, l'excitation du mouvement sismique le long de la fondation de la structure est considérée uniforme, approche cependant inadéquate pour les structures de large portance au sol localisées à proximité des failles ou sur des sites présentant une structure du sous-sol latéralement hétérogène. Cette thèse se propose donc de comprendre les facteurs clefs contrôlant localement la variabilité spatiale du mouvement sismique, avec en ligne de mire la mise en place de recommendations en vue d'incorporer ces effets dans l'estimation de l'aléa sismique et le dimensionnement des structures. La première partie de cette thèse s'intéresse à la composante intra-évènement de l'écart-type de la distribution du mouvement sismique en champ proche à l'aide de simulations numériques du mouvement sismique pour des sources étendues présentnat une cinématique de rupture réaliste. Les résultats suggèrent que la variabilité intra-évènement dépend significativement du type de rupture, cette variabilité augmentant avec la distance pour les ruptures bilatérales et diminuant pour les ruptures unilatérales. La seconde partie traite de la caractérisation de la composition du champ d'onde dans la vallée de Koutavos-Argostoli, qui est une vallée de petite dimension et d'épaisseur sédimentaire faible, située sur l'île – sismiquement active - de Céphalonie en Grèce. Les champs d'onde générés par 46 séismes, ayant des magnitudes variant entre 2 et 5 et des distances épicentrales jusqu'à 200 km, ont été analysés à partir de l'enregistrement par deux réseaux denses de capteurs sismologiques. L'algorithme de traitement d'antenne MUSIQUE est utilisé pour extraire la vitesse, l'azimut, le type et la polarisation des ondes dominantes se propageant à travers le réseau. Les résultats montrent clairement d'importantes diffractions d'ondes de surface aux bords de vallée au-delà de la fréquence de résonance de la vallée. Tandis que les ondes de Love dominent clairement le champ d'ondes proche de la fréquence de résonance, les ondes de Rayleigh dominent à plus haute fréquence dans des gammes de fréquences étroites. Par ailleurs, un excellent accord est observé entre les champs d'onde de surface diffractés localement et les caractéristiques d'amplification du site. La “cohérence décalée” de la partie la plus énergétique du signal a été quantifiée pour chaque paire de stations du réseau. En général, la cohérence calculée sur les composantes horizontales diminue avec la distance entre stations et la fréquence. La cohérence sur la composante verticale indique des valeurs relativement fortes à haute fréquence. Les valeurs de cohérence apparaissent très faiblement corrélées à la magnitude, l'azimut et la distance épicentrale du séisme, mais sont au contraire liées aux caractéristiques géométriques de la vallée. La coherence est systématiquement plus forte pour les couples de capteurs orientés selon la direction parallèle à l'axe de la vallée, et moins forte pour des couples de capteurs orientés dans la direction perpendiculaires. Cette observation est en accord avec les résultats du traitement d'antenne: la prédominance d'ondes de surface diffractées sur les bords de la vallée conduit à des mouvements en phase le long de la direction parrallèle à l'axe de la vallée. Les résultats de cette thèse apporte des elements de compréhension sur la variabilité spatiale du movement sismique et ouvrent de nombreuses perspectives d'application. / Spatial variation of earthquake ground motion over short distances significantly affects the dynamic response of engineered structures with large dimensions. In current practices, the ground motion excitation across the foundation of a structure is assumed to be spatially uniform, which becomes inadequate for spatially extended structures in the near-fault region or on sites with lateral inhomogeneity. This PhD thesis seeks to understand the key parameters that locally control the ground motion spatial variability with the intent of putting forth practical propositions for incorporating such effects in seismic design and hazard assessment. The first part of the thesis addresses the within-event component of the standard deviation of ground-motion distribution in near source region by means of numerical simulation of ground motions for extended sources with realistic rupture kinematics. The results suggest that the within-event variability significantly depends on the rupture type, depicting an increase with distance for bilateral ruptures and a decrease for unilateral ruptures. The second part deals with the characterization of seismic wave field at the Koutavos-Argostoli site, a small-size, shallow, alluvial valley located in the seismically active Cephalonia Island in Western Greece. The seismic wave field was investigated from the recordings of a dense seismological array for a set of 46 earthquakes, with magnitude 2 to 5 and epicentral distance up to 200 km. The MUSIQUE array analysis algorithm was used to extract the phase velocity, back-azimuth, type and polarization of the dominant waves crossing the array. The results clearly indicate dominant scattering of seismic surface waves, mainly from the valley-edge directions, beyond the fundamental frequency of the valley. While Love surface waves clearly dominate the wave field close to the resonance frequency, Rayleigh waves strongly dominate only in relatively narrow frequency bands at higher frequency. Besides, an excellent consistency is observed between the dominance of the identified surface wave type in the wave field and the site amplification. The "lagged coherency" of the most energetic part of the ground motion has been quantified for each station-pair within the array. In general, spatial coherency estimated from the horizontal components exhibit decays with frequency and interstation distance. Estimates from the vertical component exhibit rather larger values at some higher frequencies. Although coherency does not show any consistent trend indicating dependence on the magnitude, back-azimuth or site-to-source distance of the event, it seems to be primarily controlled by the site geometry. Larger coherency is systematically observed when the station pair is oriented parallel to the valley axis, while lower values are observed in the perpendicular direction. This observation proves to be consistent with the MUSIQUE analysis results: the predominance of scattered surface waves propagating across the valley implies an in-phase motion along valley-parallel direction and out-of-phase motion along valley-perpendicular direction. The findings of the present research are expected to contribute in enhancing our understanding of spatial variability of ground motion and improving the coherency models used in engineering. This work also opens up new insights and many questions in need of further investigation.

Understanding the complex dynamics that underpin the response of structures in the occurrence of earthquakes is of paramount importance in ensuring community resilience. The operational continuity of structures is influenced by the performance of nonstructural components, also known as secondary structures. Inherent vulnerability characteristics, nonlinearities and uncertainties in their properties or in the excitation pose challenges that render their response determination as a non-straightforward task. This dissertation settles in the context of mathematical modelling and response quantification of seismically driven secondary systems. The case of bilinear hysteretic, rigid-plastic and free-standing rocking oscillators is first considered, as a representative class of secondary systems of distinct behaviour excited at a single point in the primary structure. The equations governing their full dynamic interaction with linear primary oscillators are derived with the purpose of assessing the appropriateness of simplified analysis methods where the secondary-primary feedback action is not accounted for. Analyses carried out in presence of pulse-type excitation have shown that the cascade approximation can be considered satisfactory for bilinear systems provided the secondary-primary mass ratio is adequately low and the system does not approach resonance. For the case of sliding and rocking systems, much lighter secondary systems need to be considered if the cascade analysis is to be adopted, with the validity of the approximation dictated by the selection of the input parameters. Based on the premise that decoupling is permitted, new analytical solutions are derived for the pulse driven nonlinear oscillators considered, conveniently expressing the seismic response as a function of the input parameters and the relative effects are quantified. An efficient numerical scheme for a general-type of excitation is also presented and is used in conjunction with an existing nonstationary stochastic far-field ground motion model to determine the seismic response spectra for the secondary oscillators at given site and earthquake characteristics. Prompted by the presence of uncertainty in the primary structure, and in line with the classical modal analysis, a novel approach for directly characterising uncertainty in the modal shapes, frequencies and damping ratios of the primary structure is proposed. A procedure is then presented for the identification of the model parameters and demonstrated with an application to linear steel frames with uncertain semi-rigid connections. It is shown that the proposed approach reduces the number of the uncertain input parameters and the size of the dynamic problem, and is thus particularly appealing for the stochastic assessment of existing structural systems, where partial modal information is available e.g. through operational modal analysis testing. Through a numerical example, the relative effect of stochasticity in a bi-directional seismic input is found to have a more prominent role on the nonlinear response of secondary oscillators when compared to the uncertainty in the primary structure. Further extending the analyses to the case of multi-attached linear secondary systems driven by deterministic seismic excitation, a convenient variant of the component-mode synthesis method is presented, whereby the primary-secondary dynamic interaction is accounted for through the modes of vibration of the two components. The problem of selecting the vibrational modes to be retained in analysis is then addressed for the case of secondary structures, which may possess numerous low frequency modes with negligible mass, and a modal correction method is adopted in view of the application for seismic analysis. The influence of various approaches to build the viscous damping matrix of the primary-secondary assembly is also investigated, and a novel technique based on modal damping superposition is proposed. Numerical applications are demonstrated through a piping secondary system multi-connected on a primary frame exhibiting various irregularities in plan and elevation, as well as a multi-connected flexible secondary system. Overall, this PhD thesis delivers new insights into the determination and understanding of the response of seismically driven secondary structures. The research is deemed to be of academic and professional engineering interest spanning several areas including seismic engineering, extreme events, structural health monitoring, risk mitigation and reliability analysis.