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L'objectif majeur de la présente thèse de doctorat est la validation structurelle d’une connexion hybride plancher-voile pour la reprise de l'action sismique dans les bâtiments en béton armé à voiles. Le manque de références normatives et scientifiques pour la caractérisation de ce type de système, nous a conduits à concevoir un protocole de caractérisation original basé principalement sur une analyse expérimentale à grande échelle du comportement de la liaison plancher-voile. Tout d'abord, nous présentons quelles ont été les problématiques et les exigences qui ont amené à l'innovation du rupteur de ponts thermiques SLABE, connexion hybride pour la jonction plancher-voile. Nous analysons ensuite les protocoles de caractérisation cyclique pour les systèmes structurels similaires ("coupling beams" ou "shearheads"). Sur base de cette réflexion, nous proposons un programme expérimental composé de trois séries d'essais: deux campagnes à grande échelle visant à restituer au mieux les configurations courantes de chargement dans un bâtiment (sollicitations horizontales et verticales), et une campagne d'essais d'ancrage. Ces essais sont capables de caractériser le comportement de la liaison dans les trois directions de l’espace. Les résultats de chaque campagne d'essais sont présentés dans le détail. Ils montrent notamment que la connexion étudiée, sous chargement cyclique, se comporte de façon quasi-élastique et stable pour les niveaux de charge correspondant aux sollicitations sismiques en France métropolitaine. De plus, ces essais ont souligné la grande réserve de ductilité du système, permettant une redistribution des efforts et contribuant ainsi à une meilleure robustesse du système, indispensable pour une sollicitation sismique présentant, par nature, un fort degré d’incertitude. Enfin, nous évaluons l'impact de la connexion plancher-voile sur le comportement structurel des bâtiments au travers d’une analyse structurelle sur des ouvrages de référence. Nous analysons la réponse modale et la redistribution des efforts entre les voiles de contreventement. Cette évaluation nous permet de définir une démarche de dimensionnement pour les ouvrages béton armé munis de ces éléments et de proposer des outils de calcul adaptés à l’ingénieur. L’exhaustivité de la démarche de validation présentée en fait une référence, déjà reconnue par les instances décernant les agréments techniques français, et qui pourrait être proposée comme protocole standard pour la validation des systèmes de rupteurs de ponts thermiques ou de liaison plancher-voile, au niveau européen. / The main objective of the PhD thesis is the structural evaluation of a hybrid structural connection at the slab-to-wall junction in concrete shear wall buildings under seismic action. The lack of normative and scientific literature for the characterization of this kind of systems leads us to devise an original protocol for the characterization which is mainly built on a large-scale experimental analysis of behaviour of the slab-towall connection. First, we explain the reasons that led us to design an innovative thermal break system, the SLABE, which is thermally insulated hybrid connection for the slab-to-wall junction. Then we analyse the existing protocols for the cyclic characterization of similar structural systems ("coupling beams" or "shearheads"). Based on the outcome of this investigation, we propose an experimental program composed with three test series: two large-scale campaigns where the actual loading conditions in a building are reproduced (horizontal and vertical shear forces) and an axial test campaign. The test results provided the required information to correctly characterize the behaviour of the hybrid connection in the three directions in space. The results of the experimental campaigns are presented in detail. In particular, they show that the connection, under cyclic loads, exhibits a quasi-elastic and stable behaviour at usual seismic load levels, in France. In addition, these tests highlight the large reserve of ductility of the system that guarantees the robustness of the system. This is essential for seismic actions which have by nature a high degree of uncertainty. The impact of the slab-to-wall connexion on the structural behaviour of buildings is evaluated through a structural analysis on representative structures. We particularly analyse the modal response and the force redistribution between the internal and external shear walls. Based on the outcome of this study, we suggest a seismic design method for reinforced concrete structures equipped with these structural elements. Along with that, we propose a computational tool for engineers. The completeness of the presented validation approach makes it a benchmark, already recognized by the French authorities granting technical approvals. It could be proposed as a standard protocol for the validation of other thermal break systems or hybrid slab-to-wall connections, at European level.

<div>Observations from experiments and post-earthquake surveys have shown that drift is the key parameter for identifying potential damage of a structure during ground motions (Sozen, 1981). These observations suggest that drift should govern seismic design and evaluation of structures.</div><div><br></div><div>In this study, three methods for estimating drift demands were considered: 1) the method proposed by Sozen (2003) referred to in this study as Velocity of Displacement (VOD), 2) the Coefficient Method and 3) Nonlinear Dynamic Analysis (NDA). The reliability of each method was evaluated by comparing estimates of roof and maximum story drift ratios with measurements from 46 reinforced concrete structures with initial periods shorter than 3 seconds.</div><div><br></div><div>Measurements from long-period structures (with periods longer than 3 seconds) were not available. To produce data to evaluate the reliability of the three mentioned methods for</div><div>long-period structures as well as understand the displacement and base-shear response of such structures, seven scaled Multi-Degree-of-Freedom (MDOF) specimens with an initial period of approximately 1.2 seconds were tested with five scaled base motions of varying intensities. Each motion was scaled in time such that its scaled spectral shape near the initial period of the specimen was similar to the spectral shape of the unscaled motions for periods ranging from approximately 1 to 10 seconds. A total of 118 tests were conducted.</div><div><br></div><div>The effect of loading history on drift demands and drift estimates was also evaluated by quantifying changes in drift demands of structures subjected to repeats of the same ground motion. Data from 1) experimental tests of structures subjected to repeated ground motions, and 2) numerical analyses of Single-Degree-of-Freedom (SDOF) oscillators subjected to multiple sequences of ground motions of varying intensities were used.</div><div><br></div><div><div>Based on comparisons of measured and calculated drifts as well as data from the experimental program, the following observations were made:</div></div><div><br></div><div>1) For structures with periods shorter than 3 seconds, all three methods for estimating drift demands produced estimates of both roof and maximum story drifts of similar</div><div>quality despite large differences in the effort required to use each method.</div><div><br></div><div>2) For structures with periods longer than 3 seconds, NDA produced drift estimates close to the mean of measured values while VOD overestimated measured values, on average, by approximately 30%. The Coefficient Method produced estimates that were, on average, smaller than measurements by approximately 40%.</div><div><br></div><div>3) For structures (not susceptible to decay in lateral strength) subjected to sequences of ground motions of similar intensities, the relative increase in drift demands was,</div><div>on average, no more than 20%. Larger increases in drift demands were observed for structures where the first motion (in a pair of repeated motions) was mild enough</div><div>not to cause cracking and/or yielding, and the second motion was preceded by larger intensity motions that did cause cracking and/or yielding.</div><div><br></div><div>4) For test structures with periods longer than 3 seconds, drifts in the nonlinear range of response were generally smaller than linear estimates, and maximum base-shear</div><div>demands were as much as three times those calculated assuming a linear lateral load distribution.</div>

<p>Masonry infills historically have increased in-plane stiffness and reduced drift demands of reinforced concrete frames. An inherent risk remains during intense ground motions that unreinforced masonry infills can develop shear cracks, fail out-of-plane, or lead to the formation of captive-column conditions. This study explored the use of full-bay, plywood panel infills in non-ductile reinforced concrete frames as a novel seismic retrofit. Wood infills were constructed from layers of APA 3/4” Rated Sheathing plywood panels. Infills were tested using two single-bay, single-story concrete frames at 1/3 scale, with initial periods between 0.1 and 0.3 seconds once infilled. External post-tensioning was provided to the columns during all series to prevent column shear failure and doubled as dowel connections between the concrete frame and wood panel infill. Test series were performed on a uniaxial earthquake simulator with the frame bay parallel to the direction of ground motion. Wood infills were approximately 0.36∗𝑏, 0.18∗𝑏, and 0.09∗𝑏 thick, where b is the column width. Multi-layer infills were screw-laminated via a 6” square grid. Infills were tested in previously damaged and nominally pristine frames.</p> <p>During similar ground motions, masonry infills reduced the effective period of the pristine bare frame by approximately 50%. In nominally pristine frames, one-panel plywood infills reduced the bare frame period by a maximum of 50%, and two-panel infills by 60%. One and two-panel wood infills reduced drift demands in comparison to the pristine bare frame by a factor of 1√2∗𝑛 in previously damaged frames and by 12∗𝑛 in nominally pristine frame, where n is the number of panels of plywood across the infill thickness. There was no extra reduction in drift demands resulting from increasing the wood infill thickness beyond two panels. One-panel wood infills failed via out-of-plane buckling causing splitting at a drift demand of approximately 1.5%.</p> <p>The results of this study confirm that wood panel infill retrofits are structurally viable alternatives to stiffen non-ductile reinforced concrete frames. Plywood panel infills reduced drift demands more efficiently per unit thickness and unit weight than masonry infills; the resilience and ease of construction of wood infills suggest expanded use should be explored. Experimental study of full-scale wood infills is needed before this retrofit method could become field deployable.</p>

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第18801号 / 理博第4059号 / 新制||理||1584(附属図書館) / 31752 / 京都大学大学院理学研究科地球惑星科学専攻 / (主査)教授 岩田 知孝, 教授 平原 和朗, 准教授 久家 慶子 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

In Sweden, buildings are not designed to withstand earthquakes due to the rarity of an earthquake event and its consequential damage. However, the aim of this thesis was to study the seismic performance of some of the highest buildings in Stockholm, called Innovationen and Helix. The purpose of the study was to get an understanding of earthquake engineering for high rise buildings and to compare the behavior of the two towers during seismic action. In order to compare the two buildings and get an understanding of what will affect the seismic performance, Eurocode 8 was used. The Eurocode standard lists several properties that impacts the seismic resistance of buildings. One of the goals was to study how those factors influence the behavior of Innovationen and Helix and finally compare the results to each other in order to draw valid conclusions. The method to perform the analysis was a modal analysis using a finite element analysis program. The program used contains predefined response spectra’s based on Eurocode 8 which is used to define the seismic load acting on the structures. The extracted results are listed below: - Frequencies and mode shapes - Modal masses - Level and total masses - Accelerations - Displacements The conclusion of the study was that Innovationen and Helix have similar properties and some points from Eurocode 8 were better fulfilled by Helix and others by Innovationen: - Uniformity, symmetry and redundancy (Innovationen fulfills the requirements better than Helix) - Bi-directional resistance and stiffness (Innovationen fulfills the requirements better than Helix) - Torsional resistance and stiffness (Helix fulfills the requirements better than Innovationen) - Adequate foundation (Helix fulfills the requirements better than Innovationen) Of the two parameters studied, the height was the one with the most influence on seismic resistance.

This study aims to examine the motivation, experience and benefits of Nepalese domestic tourists visiting the seismic memorial sites after the 25 April 2015 earthquake (known as Gorkha earthquake). A total of 403 surveys was gathered from seismic sites of Nepal (Kathmandu, Bhaktapur and Patan). Data were tested to analyze why the tourists are interested in disaster sites and how their experience during their visit impact the benefits of the visits. Additionally, partial least square structural equation modeling (PLS-SEM) was employed to test the relationships among tourist motivations, experiences, and perceived benefits at the dark tourism sites in Nepal. Among the five motivational factors discovered, the empirical results depict that emotional reaction is the strongest factor of the dark tourism motivation, affecting both cognitive and affective experiences. Additionally, this study confirms that cognitive experience is more influenced by dark tourism motivations than affective experience. Among the four experience factors examined in the study, self-reflection is found to have the strongest impact of three aspects of perceived dark tourism benefits, such as knowledge gain, fulfillment, and appreciation. Overall, the findings of the study provide important implications to the management sectors of dark tourism sites, enhancing the importance of providing cognitive experiences (i.e. distributing the educational materials about the dark tourism events and offering the knowledgeable tour guide who can guide the sites) and affective experience of the tourists (storytelling about the events, organizing educational and volunteering programs at the sites). Further, this study contributes to the limited literature in the context of dark tourism and provide important managerial and practical implications based on the case of Nepal earthquake in 2015.

Accurately predicting the response of complex bridge structures to strong earthquake ground motion requires the use of sophisticated nonlinear dynamic analysis computer programs not generally available to the bridge design engineer. The analytical tools that have been developed are generally applicable to bridges whose substructures can be idealized as beam-columns. Bridges with wall piers do not belong to this category The major objective of this study is to develop an analysis tool capable of simulating the effects of earthquakes on monolithic concrete wall pier bridges. Thus, after surveying the literature, a mathematical model is developed for the geometrically nonlinear earthquake analysis of wall pier bridges. Mixed plate elements are used to model the wall pier. The plate element has eight nodes and the degrees of freedom per node are three displacements and three moments. Beam elements are used to model the bridge deck. The beam element accounts for shear deformation and it has two nodes with three displacements and three rotations as degrees of freedom per node. A transitional element is used to join the beam elements to the plate elements. The equation of dynamic equilibrium is solved using the Newmark method with modified Newton-Raphson type iteration at each time step. The mixed plate element is used to model two plate structures and the results are compared with analytical and other finite element solutions. A two span wall pier bridge is modeled using the structural elements developed in this study. The digitized time history for the N-S component of the El Centro Earthquake of May 18, 1940, is used to seismically excite the bridge model. / Ph. D.

To obtain the rupture history of the Parkfield, California, earthquake, we perform 12 kinematic inversions using elliptical sub-faults. The preferred model has a seismic moment of 1.21 x 10^18 Nm, distributed on two distinct ellipses. The average rupture speed is ~2.7 km/s. The good spatial agreement with previous large earthquakes and aftershocks in the region, suggests the presence of permanent asperities that break during large earthquakes. We investigate our inversion method with several tests. We demonstrate its capability to retrieve the rupture process. We show that the convergence of the inversion is controlled by the space-time location of the rupture front. Additional inversions show that our procedure is not highly influenced by high-frequency signal, while we observe high sensitivity to the waveforms duration. After considering kinematic inversion, we present a full dynamic inversion for the Parkfield earthquake using elliptical sub-faults. The best fitting model has a seismic moment of 1.18 x 10^18 Nm, distributed on one ellipse. The rupture speed is ~2.8 km/s. Inside the parameter-space, the models are distributed according the rupture speed and final seismic moment, defining a optimal region where models fit correctly the data. Furthermore, to make the preferred kinematic model both dynamically correct while fitting the data, we show it is necessary to connect the two ellipses. This is done by adopting a new approach that uses b-spline curves. Finally, we relocate earthquakes in the vicinity of the Darfield, New-Zealand earthquake. 40 years prior to the earthquake, where there is the possibility of earthquake migration towards its epicentral region. Once it triggers the 2010-2011 earthquake sequence, we observe earthquakes migrating inside regions of stress increase. We also observe a stress increase on a large seismic gap of the Alpine Fault, as well as on some portions of the Canterbury Plains that remain today seismically quiet.

Structural health monitoring (SHM) systems is a relatively new discipline, studying the structural condition of buildings and other constructions. Current SHM systems are either wired or wireless, with a relatively high cost and low accuracy. This thesis exploits a blend of digital signal processing methodologies, for structural health monitoring (SHM) and develops a wireless SHM system in order to provide a low cost implementation yet reliable and robust. Existing technologies of wired and wireless sensor network platforms with high sensitivity accelerometers are combined, in order to create a system for monitoring the structural characteristics of buildings very economically and functionally, so that it can be easily implemented at low cost in buildings. Well-known and established statistical time series methods are applied to SHM data collected from real concrete structures subjected to earthquake excitation and their strong and weak points are investigated. The necessity to combine parametric and non-parametric approaches is justified and to this direction novel and improved digital signal processing techniques and indexes are applied to vibration data recordings, in order to eliminate noise and reveal structural properties and characteristics of the buildings under study, that deteriorate due to environmental, seismic or anthropogenic impact. A characteristic and potential harming specific case study is presented, where consequences to structures due to a strong earthquake of magnitude 6.4 M are investigated. Furthermore, is introduced a seismic influence profile of the buildings under study related to the seismic sources that exist in the broad region of study.