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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1191

Comportement mécanique sous sollicitations alternées de voiles béton armé renforcés par matériaux composites / Mechanical behavior of RC walls under seismic activity strenghtened with CFRP

Qazi, Samiullah 17 January 2013 (has links)
Les enquêtes récentes sur les séismes ont fait ressortir l'importance des murs en béton armé en tant que partie intégrante des structures. L’évolution des règlements prend en compte ces considérations, par contre le bâti existant doit subir des renforcements dans l’objectif de leur mise en conformité. Dans cette thèse une étude expérimentale faite sur douze murs (six élancés et six courts) renforcés par un collage externe en composite a été conduite. Les murs ont été conçus en étant sous-renforcés à la flexion et cisaillement. Quatre de ces six échantillons ont été renforcés par des bandes de PRFC collées. Deux spécimens, un témoin et un renforcé, ont été soumis à un test de chargement statique et quatre échantillons, l'un témoin et trois rénovés, ont été soumis à des essais de charge cyclique. La discussion et l’analyse des tests incluent la description de la fissuration, l’analyse de la rigidité, de la capacité de charge ultime, de la ductilité. / Recent earthquake surveys have revealed the significance of RC walls as an integral part of structures. It reduces the structure damage to some extent. However, like other structural member they too are vulnerable. Researchers on basis of their post eartthquake survey and laboratary experiments have concluded that the RC wall buildings sustained damage, mainly due to design and construction work flaws. In this thesis experimental result of shear walls is discussed. They were designed under-reinforced to fail in shear in ase of short wall and in flexure for slender walls. Three out of these six specimens, in each case, were strengthened externally with CFRP strips bonded to wall panel and mesh anchors installed at wall foundation joint. Two specimens, one RC and one CFRP retrofitted (short and slender wall each), were subjected to static load test and three specimens, one RC and two to three CFRP retrofitted, were subjected to quasi static cyclic load tests. The test result analysis discussion includes failure mode, stiffness, ultimate load capacity, ductility, and energy dissipation.
1192

Vliv technické a přírodní seizmicity na stavební konstrukce se zaměřením na konstrukce ze zdicích materiálů / Influence of technical and natural seismicity on building structures with focus on structures of masonry materials

Čada, Zdeněk January 2014 (has links)
The dissertation deals with selected issues in the field of the calculation of the response of building structures which are excited with dynamic non-stationary displacement loading of its ground. Seismic load has been assumed. Procedures, how to work with seismic records with respect to the accuracy of dynamic calculations, how to modify the response spectrum to ensure the reliability, how to generate synthetic accelerogram requiring more accurate response, are recommended. Synthetic akcelerogram has been generated by own approaching, which has been used as the excitation function in the experimental seismic testing of autoclaved concrete brick building in model scale. Response values of motion in the measured points of the experiment were compared with the linear and nonlinear dynamic calculations by using the finite element method models. Different levels of detail of the numerical models have been used. The shear wall behaviour has been modelled by using constitutive models with brittle failure as well as using of non-linear interaction interface with possible delamination between the masonry bricks. The behaviour of the mathematical model of wall systems has been calibrated with respect to the measured data at shear wall experiments in real and model scale of walls.
1193

大規模災害時における自治体間協力やNPO/NGOによる人的支援に対する被災自治体の受援力の研究 : 東日本大震災を対象として / ダイキボ サイガイジ ニオケル ジチタイカン キョウリョク ヤ NPO/NGO ニヨル ジンテキ シエン ニ タイスル ヒサイ ジチタイ ノ ジュエンリョク ノ ケンキュウ : ヒガシニホン ダイシンサイ オ タイショウ トシテ

本莊 雄一, Yuichi Honjo 20 March 2016 (has links)
今後発生することが懸念されている大規模災害に備えて,より迅速で効果的な人的支援のあり方,特に人的支援に対する被災自治体の受援力の強化方策を検討するために,東日本大震災の初動期から応急対応期における人的支援について,自治体間協力や,単体としてのNPO/NGO,行政とNPO/NGOとから構成されるネットワーク組織という3つの組織形態別に,緊急社会システムを構成する組織の視点から実証分析を行う. / 博士(社会学) / Doctor of Philosophy in Sociology / 同志社大学 / Doshisha University
1194

Machine-aided Bridge Vulnerability and Condition Management

Xin Zhang (18364206) 15 April 2024 (has links)
<p dir="ltr">Bridge safety has been a longstanding priority for civil engineers. Engineers and researchers devote significant effort toward establishing the ability to detect and monitor damage and to manage the performance of our bridges over their lifecycle. However, current practices, heavily reliant on manual involvement, still present challenges in efficiency and effectiveness. For instance, rapid bridge vulnerability assessment methods are being developed, but these methods normally require information about the bridge, e.g., substructure type, which is not readily available in most current bridge databases (e.g., National Bridge Inventory). Manually collecting the necessary information for each bridge is time-consuming and would influence the use of those rapid bridge vulnerability assessment methods. Similarly, routine bridge inspection, mandated every two years in the United States, requires organizing inspection photos, evaluating bridge condition, etc., which are also time-consuming tasks. A two-year inspection cycle may be overly cautious, especially in the early stages of its life when there is typically little degradation. Furthermore, when conducting an inspection there is no reference for when to use advanced inspection techniques, so visual inspection, the simplest method, is adopted for most bridges. Given these challenges in bridge asset management, the integration of machine learning to use the data from historical records of bridge performance can aid in and serve to expedite the above tasks.</p><p dir="ltr">The objective of this research is to develop machine learning-based methods that can assist humans in completing certain tasks associated with bridge asset management. Towards this objective, the following research tasks are carried out. In Task 1, a CNN-based bridge substructure identifier is developed to automatically recognize the bridge substructure type from an inspection image. A method is developed to set a rational budget for this work based on risk tolerance. In Task 2, the automated bridge inspection image organization tool (ABIRT) is developed to automate the process of organizing inspection images and generating an inspection report. In Task 3, a technique for machine-assisted bridge damage analysis using visual data is developed and validated. Additionally, a decision-making method is established to assist bridge inspectors in adopting this technique, with a focus on managing costs and minimizing risks. And in Task 4, reinforcement learning-based approach is developed to manage the bridge inspection process. Through this research, several key machine learning techniques are explored to assist bridge managers with the more tedious steps involved in the seismic vulnerability analysis and condition management tasks, allowing the engineer to dedicate more time to making decisions. This highly cross-disciplinary research is scalable and expandable to many other applications and will serve to improve the future safety and reliability of our infrastructure.</p>
1195

Self-Management of Disaster Risk and Uncertainty: The Role of Preventive Health in Building Disaster Resilience

Gowan, Monica Elizabeth January 2011 (has links)
One of the great challenges facing human systems today is how to prepare for, manage, and adapt successfully to the profound and rapid changes wreaked by disasters. Wellington, New Zealand, is a capital city at significant risk of devastating earthquake and tsunami, potentially requiring mass evacuations with little or short notice. Subsequent hardship and suffering due to widespread property damage and infrastructure failure could cause large areas of the Wellington Region to become uninhabitable for weeks to months. Previous research has shown that positive health and well-being are associated with disaster-resilient outcomes. Preventing adverse outcomes before disaster strikes, through developing strengths-based skill sets in health-protective attitudes and behaviours, is increasingly advocated in disaster research, practise, and management. This study hypothesised that well-being constructs involving an affective heuristic play vital roles in pathways to resilience as proximal determinants of health-protective behaviours. Specifically, this study examined the importance of health-related quality of life and subjective well-being in motivating evacuation preparedness, measured in a community sample (n=695) drawn from the general adult population of Wellington’s isolated eastern suburbs. Using a quantitative epidemiological approach, the study measured the prevalence of key quality of life indicators (physical and mental health, emotional well-being or “Sense of Coherence”, spiritual well-being, social well-being, and life satisfaction) using validated psychometric scales; analysed the strengths of association between these indicators and the level of evacuation preparedness at categorical and continuous levels of measurement; and tested the predictive power of the model to explain the variance in evacuation preparedness activity. This is the first study known to examine multi-dimensional positive health and global well-being as resilient processes for engaging in evacuation preparedness behaviour. A cross-sectional study design and quantitative survey were used to collect self-report data on the study variables; a postal questionnaire was fielded between November 2008 and March 2009 to a sampling frame developed through multi-stage cluster randomisation. The survey response rate was 28.5%, yielding a margin of error of +/- 3.8% with 95% confidence and 80% statistical power to detect a true correlation coefficient of 0.11 or greater. In addition to the primary study variables, data were collected on demographic and ancillary variables relating to contextual factors in the physical environment (risk perception of physical and personal vulnerability to disaster) and the social environment (through the construct of self-determination), and other measures of disaster preparedness. These data are reserved for future analyses. Results of correlational and regression analyses for the primary study variables show that Wellingtonians are highly individualistic in how their well-being influences their preparedness, and a majority are taking inadequate action to build their resilience to future disaster from earthquake- or tsunami-triggered evacuation. At a population level, the conceptual multi-dimensional model of health-related quality of life and global well-being tested in this study shows a positive association with evacuation preparedness at statistically significant levels. However, it must be emphasised that the strength of this relationship is weak, accounting for only 5-7% of the variability in evacuation preparedness. No single dimension of health-related quality of life or well-being stands out as a strong predictor of preparedness. The strongest associations for preparedness are in a positive direction for spiritual well-being, emotional well-being, and life satisfaction; all involve a sense of existential meaningfulness. Spiritual well-being is the only quality of life variable making a statistically significant unique contribution to explaining the variance observed in the regression models. Physical health status is weakly associated with preparedness in a negative direction at a continuous level of measurement. No association was found at statistically significant levels for mental health status and social well-being. These findings indicate that engaging in evacuation preparedness is a very complex, holistic, yet individualised decision-making process, and likely involves highly subjective considerations for what is personally relevant. Gender is not a factor. Those 18-24 years of age are least likely to prepare and evacuation preparedness increases with age. Multidimensional health and global well-being are important constructs to consider in disaster resilience for both pre-event and post-event timeframes. This work indicates a need for promoting self-management of risk and building resilience by incorporating a sense of personal meaning and importance into preparedness actions, and for future research into further understanding preparedness motivations.
1196

Ανάλυση οριακής κατάστασης και σεισμικής επάρκειας λίθινων αψίδων / Limit state analysis and earthquake resistance of masonry arches

Αλεξάκης, Χαράλαμπος 09 July 2013 (has links)
Η παρούσα διατριβή επανεξετάζει την οριακή ανάλυση ευστάθειας των λίθινων αψίδων. Η οριακή ανάλυση ευστάθειας χρησιμοποιείται σήμερα ως το βασικό εργαλείο αποτίμησης της ευστάθειας τόξων και θολωτών κατασκευών από τοιχοποιία, όπως ακριβώς συνέβαινε και τους τελευταίους τέσσερις αιώνες. Παρά την τόσο μακρόχρονη ιστορία της μεθόδου, δεν έχουν πλήρως διασαφηνιστεί στην επιστημονική κοινότητα θεμελιώδης έννοιες και δεν έχουν σαφώς απαντηθεί ερωτήματα όπως: Ποιες είναι οι φυσικά πραγματοποιήσιμες γραμμές ώθησης και ποιες όχι; Ποια είναι η επίδραση της στερεοτομίας ενός τόξου στην οριακή του ευστάθεια; Ποιος είναι ο ρόλος της αλυσοειδούς καμπύλης και κατά πόσο αυτή είναι μία φυσικά αποδεκτή γραμμή ώθησης; Τι σχέση υπάρχει ανάμεσα στην κλίση της συνισταμένης θλιπτικής δύναμης και στην κλίση της γραμμής ώθησης στο σημείο εφαρμογής της; Η παρούσα διατριβή αναζητά απαντήσεις στα ερωτήματα αυτά, και έχει ως στόχο τη βαθύτερη κατανόηση της οριακής ανάλυσης ευστάθειας των τόξων, με παράλληλη ανάδειξη νέων υπολογιστικών διαδικασιών. Η δομή της παρουσιάζεται συνοπτικά παρακάτω. Στο πρώτο κεφάλαιο γίνεται ιστορική ανάλυση της μεθόδου μέσα από παρουσίαση και σχολιασμό των εργασιών με τη σημαντικότερη συμβολή, από τα μέσα του 17ου αιώνα μέχρι σήμερα. Στο δεύτερο κεφάλαιο επανεξετάζεται ένα από τα πιο κλασικά προβλήματα της μηχανικής: ποιο είναι το ελάχιστο επιτρεπτό πάχος ενός ημικυκλικού τόξου υπό τη δράση του ιδίου βάρους του για να είναι ευσταθές. Παράλληλα απαντώνται τα ερωτήματα που τέθηκαν παραπάνω αναπτύσσοντας νέες κλειστές μαθηματικές εκφράσεις των γραμμών ώθησης μέσω γεωμετρικής προσέγγισης, αλλά και μέσω του λογισμού των μεταβολών. Στο τρίτο κεφάλαιο χρησιμοποιείται παρόμοια διαδικασία για την ανάλυση της γενικής περίπτωσης των ελλειπτικών τόξων, οποιουδήποτε γεωμετρικού λόγου ύψος προς βάση, καθώς δεν είναι διαθέσιμα αναλυτικά αποτελέσματα στη διεθνή βιβλιογραφία, όπως συμβαίνει για τα κυκλικά τόξα. Στο τέταρτο κεφάλαιο εξετάζεται η οριακή ευστάθεια κυκλικών τόξων οποιασδήποτε γωνίας εναγκαλισμού, υπό την ταυτόχρονη δράση του ιδίου βάρους τους και σταθερής οριζόντιας εδαφικής επιτάχυνσης, ενώ υπολογίζεται με ακρίβεια η μορφή που θα έχει ο επικείμενος μηχανισμός κατάρρευσης μαζί με το οριακό πάχος, συναρτήσει της σεισμικής φόρτισης. Τα αποτελέσματα της μαθηματικής ανάλυσης (Κεφ. 2-4) επιβεβαιώνουν την ακρίβεια του λογισμικού που αναπτύχθηκε για τις ανάγκες της διατριβής, καθώς και τα αποτελέσματα που προκύπτουν από εμπορικό λογισμικό της μεθόδου των διακριτών στοιχείων. Στο πέμπτο κεφάλαιο γίνεται εφαρμογή και σύγκριση των πιο αντιπροσωπευτικών υπολογιστικών μεθόδων που απαντώνται σήμερα στη βιβλιογραφία για την αποτίμηση της ευστάθειας και φέρουσας ικανότητας της υπόγειας Θολωτής Διόδου του Σταδίου της Αρχαίας Νεμέας, ενώ η οριακή ανάλυση ευστάθειας αναδεικνύεται ως ένα μοναδικό εργαλείο για την κατανόηση της αλληλεπίδρασης της κατασκευής με το περιβάλλον έδαφος. Επιπλέων των συμπερασμάτων στο τέλος κάθε κεφαλαίου (Κεφ. 2 έως 5), στο έκτο κεφάλαιο παρουσιάζονται τα πιο σημαντικά συμπεράσματα και η συνεισφορά της παρούσας διατριβής. / This doctoral thesis revisits the limit equilibrium analysis of masonry arches. Limit equilibrium analysis is used today as the main analysis method for the assessment of the stability of masonry arches and vaulted structures, and is the outcome of important contributions that happened during the last four centuries. Although this method has a long history and a rich literature, there are still fundamental concepts that have not been thoroughly clarified, such as: What are the physically admissible thrust lines of an arch? How the stereotomy of an arch affects its limit stability? What is the role of the catenary curve (the alysoid)? Is the catenary curve a physically admissible thrust line? What is the relation between the direction of the thrust force and the slope of the thrust line at the point of application of the force? This thesis investigates these questions and aims to a better understanding of the limit equilibrium analysis of masonry arches, and at the same time, to present innovative methodologies and new analysis tools. Chapter 1 presents the work of other authors that have contributed the most to the stability analysis of masonry arches and vaulted structures over the last centuries. Chapter 2 revisits one of the most classical problems of Mechanics—what is the minimum thickness of a semicircular masonry arch subjected to its own weight. At the same time, the analysis presented in this chapter answers to the aforementioned questions through the development of closed-form expressions of the thrust line and the application of calculus of variation. Chapter 3 is focused on the limit equilibrium state of elliptical masonry arches, using the same approaches that were used in Chapter 2. This analysis was motivated from the fact that numerical results have been available in literature only for circular and not for elliptical masonry arches. Chapter 4 computes the location of the imminent hinges and the minimum thickness of circular masonry arches, for every given embrace angle, which can just sustain their own weight, together with a given level of horizontal ground acceleration. The numerical results presented in Chapters 2 to 4 confirm the accuracy of the in-house software that was developed for the needs of this thesis and the results obtained with a representative, commercially available software of the distinct element method. Chapter 5 present a comprehensive structural analysis of the Tunnel-Entrance to the Stadium of Ancient Nemea which ranges from the thrust line limit analysis and the discrete element method, to a 3-dimensional finite-element analysis. Limit equilibrium analysis emerges as a unique analysis method for the assessment of the stability of the structure and its interaction with the surrounding soil. While at the end of every chapter (Chapters 2 to 5) are presented detailed comments and conclusions, Chapter 6 is focused on outlining the most important conclusions and the main contribution of this thesis.
1197

Seismic analysis of concrete structures within nuclear industry / Dimensionering av nukleära betongkonstruktioner med avseende på seismisk påverkan

Tabatabaei Araghi, Pedram January 2014 (has links)
Earthquake has always been a hazard for civil structures and keeping the structures integrity during and after an earthquake is of vital importance. This phenomenon’s impact is sudden and there is little or no warning to make the preparations for this natural disaster. Much damage has been done on structures which have led to major collapses and loss of many lives. Civil structures such as nuclear power plants are designed to withstand earthquakes and in the event of a major seismic event, to shut down safely. The aim of this thesis is to present the seismic design procedures for concrete structures, in basic and detailed design, according to Eurocode 8. Also to describe and understand the difference between Eurocode 8 and the DNB in seismic analysis of nuclear power plants. To evaluate the use of DNB instead of Eurocode 8 with Swedish seismic conditions is also another aim in this thesis.  Loads and actions which apply on a structure in a seismic design and corresponding load combinations are presented for Eurocode 8 and the DNB. An example is also given to clarify the design of primary seismic beams and columns with high ductility class (DCH). A case study of a nuclear structure from a test project named SMART2013 has been made by analyzing and comparing the results from Eurocode 8 and the DNB with a finite element model in FEM-Design software. Natural frequencies of the model are compared with the tested model in SMART2013-project to evaluate the finite element modeling. The model is seismically analyzed with load combinations from Eurocode 8 and the DNB with Swedish elastic ground response spectrum with the probability of 10-5. Results obtained from the primary seismic beams and columns are compared and analyzed.  Being on the safe and conservative side of the design values is always preferred in seismic analysis of a vital and sensitive structure such as nuclear power plants. The results from this thesis shows that, purely structural, combination of Swedish elastic ground response spectrum with the Eurocode 8 load combination will give more conservative values than the DNB. / I stora delar av världen har jordbävningar alltid varit ett hot för byggnaders integritet. Karaktären av en jordbävning är plötslig och föranleds av små eller inga varningar. Om jordbävningen medför att byggnader kollapsar sker ofta stora förluster av människoliv direkt eller indirekt. Kärnkraftsverk är anläggningar som dimensioneras för att klara jordbävningar och ska kunna gå till säker avställning vid en sådan händelse. Syftet med föreliggande rapport är att presentera hur betongkonstruktioner dimensioneras för jordbävning enligt Eurokod 8. Rapporten redogör även för skillnader mellan att dimensionera enligt Eurokod 8 och DNB (Dimensionering av nukleära byggnadskonstruktioner) samt hur det slår att använda Eurokod med svenska seismiska förhållanden. Laster och lastkombinationer som används vid jordbävningsdimensionering av betongbyggnader är presenterad enligt både Eurokod och DNB. Ett exempel presenteras för att visa hur primära balkar och pelare med hög duktilitetsklass (DCH) dimensioneras för seismisk påverkan. En fallstudie av en nukleär byggnad från ett internationellt projekt, SMART2013, har använts för att analysera och utvärdera resultaten från Eurokod och DNB. Byggnaden har analyserats med finita element med programvaran FEM Design. Modellens riktighet har verifierats genom att jämföra bland annat egenfrekvenser med de från officiella rapporter från SMART2013. Byggnaden är analyserad för seismisk last enligt svenska förhållanden med markresponsspektra 10-5, och primära balkar och pelare har analyserats och utvärderats enligt både Eurokod och DNB.
1198

Seismic Retrofit of Load Bearing URM Walls with Internally Placed Reinforcement and Surface-Bonded FRP Sheets

Sabri, Amirreza 22 June 2020 (has links)
Concrete block masonry is a common building material used worldwide, including Canada. Reinforced masonry buildings, designed according to the requirements of recent building codes, may result in seismically safe structures. However, unreinforced masonry (URM) buildings designed and constructed prior to the development of modern seismic design codes are extremely vulnerable to seismic induced damage. Replacement of older seismically deficient buildings with new and seismically designed structures is economically not feasible in most cases. Therefore, seismic retrofitting of deficient buildings remains to be a viable seismic risk mitigation strategy. Masonry load bearing walls are the most important elements of such buildings, potentially serving as lateral force resisting systems. A seismic retrofit research program is currently underway at the University of Ottawa, consisting of experimental and analytical components for developing new seismic retrofit systems for unreinforced masonry walls. The research project presented in this thesis forms part of the same overall research program. The experimental component includes design, construction, retrofit and testing of large-scale load bearing masonry walls. Two approaches were developed as retrofit methodologies, both involving reinforcing the walls for strength and deformability. The first approach involves the use of ordinary deformed steel reinforcement as internally added reinforcement to attain reinforced masonry behaviour. The second approach involves the use of internally placed post-tensioning tendons to attain prestressed masonry behaviour. The analytical component of research consists of constructing a Finite Element computer model for nonlinear analysis of walls and conducting a parametric study to assess the significance of retrofit design parameters. The results have led to the development of a conceptual retrofit design framework for the new techniques developed, while utilizing the seismic provisions of the National Building Code of Canada and the relevant CSA material standards.
1199

Validation and application of advanced soil constitutive models in numerical modelling of soil and soil-structure interaction under seismic loading

Kowalczyk, Piotr Jozef 23 September 2020 (has links)
This thesis presents validation and application of advanced soil constitutive models in cases of seismic loading conditions. Firstly, results of three advanced soil constitutive models are compared with examples of shear stack experimental data for free field response in dry sand for shear and compression wave propagation. Higher harmonic generation in acceleration records, observed in experimental works, is shown to be possibly the result of soil nonlinearity and fast elastic unloading waves. This finding is shown to have high importance on structural response, real earthquake records and reliability of conventionally employed numerical tools. Finally, short study of free field response in saturated soil reveals similar findings on higher harmonic generation. Secondly, two advanced soil constitutive models are used, and their performance is assessed based on examples of experimental data on piles in dry sand in order to validate the ability of the constitutive models to simulate seismic soil-structure interaction. The validation includes various experimental configurations and input motions. The discussion on the results focuses on constitutive and numerical modelling aspects. Some improvements in the formulations of the models are suggested based on the detailed investigation. Finally, the application of one of the advanced soil constitutive models is shown in regard to temporary natural frequency wandering observed in structures subjected to earthquakes. Results show that pore pressure generated during seismic events causes changes in soil stiffness, thus affecting the natural frequency of the structure during and just after the seismic event. Parametric studies present how soil permeability, soil density, input motion or a type of structure may affect the structural natural frequency and time for its return to the initial value. In addition, a time history with an aftershock is analysed to investigate the difference in structural response during the earthquake and the aftershock.
1200

Ein wellenbasiertes stochastisches Modell zur Vorhersage der Erdbebenlast / A wave-based stochastic model for seismic load prediction / Un modèle stochastique á la prévision de la charge de séisme basé sur des ondes sèismiques / Un modelo estocástico para la predicción de la carga sísmica, basada en ondas sísmicas / Стохастическая модель для прогноза сейсмической нагрузки, основаннa на сейсмических волнах

Bretschneider, Jörg 06 July 2007 (has links) (PDF)
Starke Erdbeben stellen weltweit ein hohes Risiko für urbane Zentren dar, dem unter anderem durch Methoden der aseismischen Bauwerksbemessung begegnet wird. Grundlage hierfür bilden Annahmen und Erfahrungswissen über die lokale seismische Bodenbeschleunigung, Grenzen sind hingegen durch die zusätzlichen Kosten gesetzt. Die Schadensbilanz der Starkbeben der letzten Jahre, auch in den Industrieländern, verdeutlicht die Notwendigkeit, die Konzepte und Methoden des erdbebensicheren Bauens weiter zu verfeinern. In dieser Arbeit wird ein neuer Ansatz zur stochastischen seismischen Lastmodellierung vorgestellt, der über die übliche Annahme eines stationären, eindimensionalen Prozesses für die Bodenbeschleunigung hinausgeht. Ziel ist eine standort- und wellenspezifische räumliche Lastmodellierung, die durch Nutzung von Informationen über physikalische Invarianten eine transparente und kostengünstige aseismische Bauwerksbemessung erlaubt, zumindest aber das Risiko gegenüber gebräuchlichen Bemessungsmethoden reduziert. Solche seismischen und geotechnischen Invarianten sind die gesetzmäßige Struktur des seismischen Wellenfeldes sowie die Resonanzeigenschaften der Bodenschichtung am Standort. Das vorgeschlagene Lastmodell bildet das Wellenfeld am Standort als Komposition stochastischer evolutionärer Teilprozesse auf zeitveränderlichen Hauptachsen ab, die zu Wellenzügen mit jeweils spezifischer Lastcharakteristik korrespondieren. Diese Lastcharakteristik wird sowohl im Frequenz- und Zeitbereich als auch räumlich durch wellenspezifische Formfunktionen beschrieben, deren Parameter stark zu seismischen und geotechnischen Größen korrelieren. Schwerpunkt der Arbeit sind neuartige, korrelationsbasierte Schätzverfahren zur empirischen Spezifikation der Modellparameter für die Baupraxis. Das spektraladaptive Korrelations-Hauptachsenschätzverfahren (SAPCA) sichert die optimale Erfassung der räumlichen Wellenzüge durch Transformation der Messung auf Referenzkomponenten. Gleichzeitig liefert es - in Verbindung mit einem Korrekturverfahren für den Streichwinkel der Hauptachse - prägnante, assoziierte Hauptachsenverlaufsmuster, anhand derer Dominanzphasen für drei verallgemeinerte Wellenzüge zuverlässig identifiziert werden können. Innerhalb dieser Dominanzphasen werden die wellenzugspezifischen Parameter des Lastmodells bestimmt. Außerdem wird ein Algorithmus angegeben, um Rayleighwellen in Einzelmessungen zu identifizieren. Die Eignung des Modellansatzes und die Effizienz der Schätzverfahren werden anhand von Starkbebenmessungen des Northridge-Erdbebens 1994 verifiziert. Mit dem vorgestellten nichtstationären Modellansatz werden in herkömmlichen stochastischen Lastmodellen unterschätzte Lastanteile des Starkbebenwellenfeldes genauer abgebildet. Bisher unterschlagene oder pauschal modellierte Lastanteile werden erstmals der Analyse und Modellierung zugänglich gemacht. Das stochastische Modell wird bezüglich der wichtigsten lastgenerierenden Effekte physikalisch transparent und dadurch - trotz höherer Komplexität - in der Ingenieurpraxis besser handhabbar. Die Hauptachsenmethode (SAPCA) eignet sich auch für seismologische Analysen im Nahbereich, etwa zur Analyse von Bruchprozessen und topographischen Standorteffekten. / Strong earthquakes are a potential high risk for urban centres worldwide, which is, amongst others, confronted by methods of aseismic structural design. This is based on both assumptions and thorough knowledge about local seismic ground acceleration; limits are set, on the other side, by additional costs. Damage balance of recent strong quakes - also in industrialized countries - emphasize the need for further refinement of concepts and methods of earthquake resistant structural design. In this work, a new approach of stochastic seismic load modelling is presented, letting go the usual presupposition of a stationary, one-dimensional stochastic process for ground acceleration. The goal is site and wave specific load modelling, using information about physical and geotechnical invariants, which enables transparency and low cost approaches in aseismic structural design, but at least reduces seismic risk in comparison to common design methods. Those physical and geotechnical invariants are the structure of the seismic wave field according to physical laws as well as resonance properties of the soil strata at the local site. The proposed load model represents the local wave field as a composition of stochastic evolutionary sub-processes upon time-variant principal axes, which correspond to wave trains with specific load characteristics. Those load characteristics are described in the frequency and time as well as in the spatial domain by wave-specific shape functions, whose parameters strongly correlate to seismic and geotechnical entities. Main contributions of the work are newly developed estimation procedures based on correlation, which serve in the framework of empirical specification of the model parameters for the building practice. The Spectral-Adaptive Principal Correlation Axes (SAPCA) algorithm ensures an optimal covering of the spatial wave trains by transforming the recorded data onto Reference Components. At the same time - in connection with a correction algorithm for the strike angle of the principal axis - it delivers concise associated patterns in the course of the principal axis, which are in turn used to reliably identify dominance phases for three generalized wave trains. Within those wave dominance phases, the wave specific parameters of the load model are determined. Additionally, an algorithm is presented to identify Rayleigh waves in single site acceleration records. Adequacy of the modelling approach and efficiency of the estimation procedures are verified by means of strong motion records from the 1994 Northridge Earthquake The proposed non-stationary modelling approach describes with more accuracy load portions of the strong motion wave field underestimated in conventional stochastic load models. Load portions which are left out or lump-sum modelled so far are made available for analysis and modelling for the first time. The stochastic model gains physical transparency with respect to the most important load generating effects, and hence will be - despite higher complexity - easy to handle in engineering practice. The Principal Axis method will also be useful for seismological analyses in the near field, e.g., for the analysis of rupture processes and topographic site effects. / Des séismes forts sont un gros risque potentiel pour des centres urbains dans le monde entier, qui est, entre autres, confronté par des méthodes de conception aséismique de bâtiments. Ceci est fondé sur des hypothèses et la connaissance profonde au sujet de l'accélération séismique au sol locale. Limites sont placées, de l'autre côté, par des coûts additionnels. Les dommages des séismes forts récents, aussi dans les pays industrialisés, soulignent la nécessité de raffiner plus loin les concepts et les méthodes de conception aséismique de bâtiments. Dans cette oeuvre, une nouvelle approche à la modélisation stochastique de la charge séismique est présentée, qui renonce la présupposition habituelle d'un processus stationnaire et unidimensionnel pour l'accélération de sol. L'objectif est une modélisation spatiale de charge, spécifique d'ondes et de site, qui, par l'utilisation des informations sur des invariantes physiques, permet une mesure de bâtiment asismique transparente et économique, au moins toutefois réduit le risque par rapport aux méthodes de mesures courantes. De tels invariants séismiques et géotechniques sont la structure du champ des ondes séismiques déterminé par les lois de la physique et les qualités de résonance de la stratification de sol locale. Le modèle de charge proposé décrit le champ des ondes au site comme composition des sous-processes évolutionnaires stochastiques sur les axes principales variables dans le temps, qui correspondent aux trains des ondes qu'ont une caractéristique de charge respectivement spécifique. Cette caractéristique de charge est décrit dans le domaine temporel et de fréquence et aussi bien que spatial par les fonctions de forme spécifique d'ondes dont les paramètres corrèlent fortement à des dimensions séismiques et géotechniques. Une priorité d'oeuvre sont des nouvelles procédures d'estimation, pour la spécification empirique des paramètres de modèle pour la pratique de construction, qui se basent sur la sur la corrélation de croix de composante. La procédure adaptative spectrale d'estimation d'axes principals de corrélation (SAPCA) assure la saisie optimale des trains des ondes spatiaux par la transformation des enregistrements sur des composantes de référence. En même temps - en relation avec une procédure de correction d'angle égal d'axe prin¬ci¬pal - il livre des concises schémas associés de cours d'axes principals, au moyen de ceux peut être identifié fiable des phases de dominance pour trois trains généralisés des ondes. Dans ces phases de dominance, les paramètres du modèle de charge spécifiques pour chaque train des ondes sont déterminés. En outre, un algorithme est indiqué, pour identi¬fier des ondes de Rayleigh dans un enregistrement individuel de l'accélération de sol. La qualification de l'approche de modèle et l'efficience des procédures d'estimation sont vérifiées au moyen d'enregistrements de tremblement fort du séisme á Northridge 1994. Avec l'approche de modèle non-stationnaire présentée, tels des parts de charge du champ des ondes sismiques forts sont décrites plus précisément qui sont sous-estimées dans les modèles de charge stochastiques habituels. Des parts de charge q'ont été supprimés ou modelées forfaitairement jusqu'ici, sont rendues accessibles à l'analyse et à la modélisation pour la première fois. Le modèle stochastique devient physico-transparent concernant les effets les plus importants, produisants une charge sur le bâtiment, et ainsi - malgré la complexité plus élevée - mieux maniable en pratique d'ingénieur. La méthode d'axes principals adaptative spectrale (SAPCA) convient aussi pour des analyses sismologiques dans la proximité d'epicentre, par exemple à l'analyse des processus de rupture et des effets de site topographiques. / Por todo el mundo, los terremotos fuertes son un alto riesgo potencial para los centros urbanos, que está, entre otros, enfrentado por métodos de diseño estructural antisísmico. Estos métodos son basa en asunciones y conocimiento fundamentado sobre la aceleración de tierra sísmica local; los límites son fijados, en el otro lado, por costes adicionales. Balance de los daños de temblores fuertes recientes - también en países industrializados - acentúe la necesidad del refinamiento adicional de conceptos y de métodos de diseño estructural resistente del terremoto. En este trabajo, una nueva aproximación de modelar estocástico de la carga sísmica se presenta, superando la presuposición generalmente de un proceso estocástico unidimensional y estacionario para la aceleración de tierra. La meta avisada es un modelo de la carga específico del sitio y de las ondas que, con la información sobre las invariantes físicas y geotécnicas, permite las aproximaciones transparentes y económicas, en diseño estructural antisísmico; pero por lo menos reduce el riesgo sísmico en la comparación a los métodos usados de diseño. Esos invariantes son la estructura regular del campo de las ondas sísmicas, así como las características de la resonancia de los estratos del suelo en el sitio local. El modelo propuesto de la carga representa el campo local de las ondas sísmicas como composición de los procesos parciales evolutivos estocásticos sobre las hachas principales variables-temporales, que corresponden a los trenes de las ondas con características específicas de la carga. Esas características de la carga son descritas en el dominio de la frecuencia y del tiempo así como en el dominio espacial por las funciones de la forma, que parámetros son especificas por los trenos generalizados de la onda sísmica y correlacionan fuertemente a las entidades sísmicas y geotécnicas. La contribución principal de este trabajo son los procedimientos nuevamente desarrollados de la valoración basados en la correlación, que sirven en el contexto de la especificación empírica de los parámetros de modelo para la práctica de construcción. El algoritmo de las Ejes Mayor de la Correlación Espectral-Adaptante (SAPCA) asegura la recogida óptima de los trenes espaciales de la onda transformando los datos registrados sobre componentes de la referencia. En el mismo tiempo - en la conexión con un algoritmo de la corrección para el ángulo del acimut del eje mayor/principal – SAPCA entrega los patrones asociados concisos en el curso del eje principal, que después se utilizan para identificar confiablemente las fases de la dominación para tres trenes generalizados de la onda. Dentro de esas fases de la dominación de la onda, los parámetros específicos de la onda del modelo de la carga se determinan. Además, un algoritmo se presenta para identificar las ondas de Rayleigh en solos mensuras de la aceleración del sitio. La suficiencia del aproximación que modela y la eficacia de los procedimientos de la valoración se verifican por medio de los datos del terremoto catastrófico a Northridge 1994. La aproximación non-estacionaria que modela propuesto describe con más exactitud las porciones de la carga del campo de la onda del terremoto fuerte subestimado en modelos estocásticos convencionales de la carga. Cargue las porciones que se dejan hacia fuera o modelado global hasta ahora se hace disponible para el análisis y modelar para la primera vez. El modelo estocástico gana la transparencia física con respecto a la carga más importante que genera efectos, y por lo tanto será - a pesar de una complejidad más alta - fácil de dirigir en práctica de la ingeniería. El método principal del eje también será útil para los análisis sismológicos en el campo cercano, p. e., para el análisis de los procesos de la ruptura y de los efectos topográficos del sitio. / Сильные землетрясения всемирно являются потенциально высоким риском для ур¬банизированных центров. Для уменшения сейсмического риска развивются методы антисейсмичной структурной конструкции. Эти методы построены на предположениях, которые требуют тщательного эмпирического знания характеристик местного сейсмического ускорения грунта. Предел состоит, с другой стороны, в дополнительных стоимостях строительства. Убытки от недавних сильных землетрясений - также в индустриально развитых странах – подчеркивают потребность более глубокого уточнения прин¬ципиальных схем и методов антисейсмичного строительства. Эта работа представляет новый подход стохастического сейсмического моде¬лирования нагрузки, развивающий обычное предположениe стационарного, одномерного стохастического процессa нa сейсмическое ускорение грунта. Целью будет создание модели нагрузки, которая указана по отдельности для специфических характеристик и сейсмических волн и местного положения, делающей возможным, путём использования информации о физических и геотехничес¬ких инвариантностях, и прозрачных и недорогих подходов в антисейсмичной структурной конструкции, но по крайней мере уменьшающей сейсмический риск, по сравнению с общими методами антисейсмичного строительства. Эти инвариантности являются закономерной структурой волнового поля также, как и свойствами резонан¬са слоёв грунта в месте постройки.. Предложенная модель нагрузки представляет местное волновое поле как составляющая стохастических подпроцессов развития на главных осях зависящих от времени, которые соответствуют волновым пакетам со специфическими характе¬ристиками нагрузки. Те эти характеристики нагрузки описаны в диапазонах частоты и времени также, как трёхмерного объёма функциями формы, параметры которых указаны по отдельности для различных обобщанных волновых пакетов u сильно соотносят от сейсмичес¬ких и геотехнических величин. Главны вклад работы – это новые процедуры оценивания, основанные на корреляции, которые служат в рамках эмпирической спецификации модельных параметров для практики строительства. Новый Aлгоритм Спектрально-Приспо¬собительных Главных Oсей Kорреляции (SAPCA) обеспечивает оптимальное заволакивание трёхмерных волновых пакетов преобразованием записанных данных сейсмического ускорения грунта на калибровочные компоненты на этих главных осях. В то же самое время - в связи с алгоритмом коррекции для угла простирания главной оси - SAPCA поставляет сжатые связанные волновые картины в ходе временно-изменчивых глав¬ных осей, которые в свою очередь использованы для надежного определения доминантных фаз для трёх обобщенных волновых пакетов. В этих фазах засилья отдельного волного пакета, определёны волново-специфические параметры модели нагруз¬ки. Дополнительно, показан алгоритм для идентификации и определения волн типа Релея при одиночной регистрации сейсмической ускорении грунта. Адекватность моделированного подходa и эффективность процедур оценивания подтвержены посредством данных сильного землетрясения Northridge 1994. Предложенный нестационарный подход моделировании описывает с большей точностью части нагрузки волного поля сильных землетрясений недооцененных в обычных стохастических моделях нагрузки. Части нагрузки не рассматривающиеся или слишком обобщаемые до сих пор, при новым подходе впервые можно будет учитывать и анализировать. Стохастическая модель приобретает физической прозрачностей по отношению к самым важным влияниям, которые производят нагрузку, и следовательно будет – несмотря на более высокую сложность – легка для того, чтобы применять её в практике инженерных расчётов. Mетод Главных Oсей также будет полезенно для сейсмологических анализов в близком поле, например, для анализа процессов повреждения и топографических влиянии местного положения.

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