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Impact d'un service de liaison pour fractures sur des issues cliniques et d'adhésion au traitement, incluant une analyse économique des trajectoires de soinsSenay, Andréa 12 1900 (has links)
Introduction. L’ostéoporose est une maladie chronique silencieuse jusqu’à la survenue de fractures de fragilisation, qui sont des prédicteurs importants de récurrence de fractures. La prise en charge des fractures de fragilisation au moyen de traitements de prévention secondaire des fractures est sous-optimale dans la population. Dans le but de pallier à cet écart dans les soins, de multiples initiatives de prévention secondaire des fractures ont été étudiées. Ces services ont souvent un niveau d’intervention de faible intensité et/ou un accès à des soins à court terme.
Objectifs. Cette thèse comprend quatre volets liés à l’implantation d’un Service de Liaison pour Fractures (FLS) de haute intensité d’intervention ayant un suivi systématique à long terme. Le premier objectif vise à rapporter la performance de l’intervention au moyen d’indicateurs clés. Le second objectif consiste à mesurer l’usage des traitements pour l’ostéoporose dans le FLS. Le troisième objectif est d’identifier les trajectoires de soins par la présence aux visites de suivi systématique dans le FLS. L’objectif final consiste à évaluer le rapport coût-utilité en utilisant des groupes de trajectoires de soins en comparaison à la pratique clinique usuelle.
Méthodologie. Un FLS appelé le programme Lucky BoneTM a été approuvé avec un devis d’étude de cohorte prospective et implanté dans deux cliniques externes d’orthopédie en milieu hospitalier. L’intervention était multifacette ; 1) identifier les femmes et les hommes de 40 ans et plus avec une fracture ostéoporotique, 2) investiguer pour la fragilité osseuse, 3) initier un traitement préventif, et 4) intégrer les sujets à un suivi systématique de deux ans. Des données cliniques et administratives ont été collectées pour mesurer l’impact du programme. Le premier volet de cette thèse rapporte la performance du FLS. Un devis de cohorte permettait de mesurer les indicateurs clés de performance (ICPs) ; les taux d’investigation pour la densité minérale osseuse (DMO), d’initiation de traitement, de participation au suivi, et le taux d’incidence de fractures subséquentes. Les changements des valeurs sériques de biomarqueurs osseux et des scores de questionnaires sur la qualité de vie/capacité fonctionnelle/douleur étaient également mesurés au moyen de modèles à effets mixtes. Le second volet de cette thèse mesure les taux de persistance et les niveaux d’adhésion (proportion de jours couverts (PDC) > 80% = bonne adhésion) au traitement sur un et deux ans de suivi. Le troisième volet de cette thèse consiste à identifier les groupes de trajectoires de soins basées sur les fréquences des visites de suivi systématique au moyen de modélisation pour les trajectoires par group-based. Le dernier volet vise à mesurer l’impact économique de ces
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groupes de trajectoires de soins par rapport à un groupe simulé de pratique clinique usuelle, qui était modélisé au moyen d’une analyse coût-utilité et des modèles analytiques de Markov.
Résultats. Des 532 participants, 85.7% étaient des femmes et l’âge moyen était de 63±11 ans. Premier volet : Les résultats de la mesure des ICPs étaient les suivants : taux d’investigation de la DMO de près de 86%, taux d’initiation de traitement de > 86%, présence à au moins une visite de suivi pour 83.6% des sujets (22.2% de présence à toutes les visites) sur deux ans, et un taux d’incidence de fractures subséquentes de 2.6 par 100 personnes-années. Les biomarqueurs osseux ont grandement diminué en seulement six mois, suggérant une inhibition de la résorption osseuse par le traitement. Une amélioration significative de la capacité fonctionnelle a été observée dans le temps (14%-64%). Second volet : Les taux de persistance au traitement sur un et deux ans étaient de 66.4% et 55.6%, respectivement. Les proportions de patients avec un PDC > 0.8 sur un et deux ans étaient de 64.2% et 62.5%, respectivement. Troisième volet : Trois groupes de trajectoires de soins ont été prédits et interprétés comme une utilisation élevée (UE, 48.4%), une utilisation intermédiaire (UI, 28.1%) et une utilisation faible (UF, 23.5%). Quatrième volet : Les ratios coût-utilités incrémentaux des groupes UE, UI et UF par rapport à la pratique clinique usuelle étaient de 3,600$, 22,000$ et 74,000$ par année de vie pondérée par la qualité gagnée, respectivement.
Conclusions. Un FLS ayant une haute intensité d’intervention et un suivi systématique des patients avec une fracture de fragilisation a entrainé des taux d’investigation et de traitement élevés, un faible taux de récurrence de fractures, mais une participation au suivi qui pourrait être améliorée sur deux ans. Plus de la moitié des participants étaient toujours traités et avaient un usage optimal de ces traitements après deux ans. Près de la moitié des sujets appartenaient à un groupe de trajectoire de soins élevée, ce comportement s’avérant coût-efficace. La principale limite de ce programme de recherche est le manque d’un groupe de contrôle. Un essai pragmatique randomisé contrôlé est à envisager pour supporter ces résultats. Les pistes de recherches futures incluent l’investigation des comportements reliés à l’utilisation des soins chez les patients à haut risque de refracture, et ce, au moyen d’issues qualitatives centrées sur le patient. / Introduction. Osteoporosis is an asymptomatic chronic disease until the development of osteoporosis-related fractures. Furthermore, the occurrence of a previous fragility fracture strongly increases the risk of subsequent fractures. Given the current suboptimal management of fragility fractures in usual clinical practice, several secondary fracture prevention strategies have been studied. However, continuous access to care is typically not central to these interventions as they mostly involve only one visit to a specialized healthcare professional.
Objectives. This thesis had four main objectives derived from research questions focusing on the implementation of a high-intensity Fracture Liaison Service (FLS) with a systematic follow-up of two years. The first objective was to measure the performance of the intervention using key indicators. The second objective was to report on the utilization patterns of osteoporosis drugs. The third objective was to identify trajectories of compliance to follow-up care. The last objective was to evaluate the economic impact of trajectory groups of compliance to follow-up care with respect to usual care.
Methodology. An FLS intervention called the Lucky BoneTM Program was approved as a prospective cohort study and implemented in two hospital-based outpatient orthopedic clinics. The intervention encompassed four components: 1) the identification of fragility fractures in women and men aged 40 years or older, 2) the investigation for bone fragility, 3) the initiation of treatment, 4) the integration of patients to a two-year systematic follow-up. Both clinical and administrative data were collected prospectively and retrospectively to measure the impact of the intervention. The first component of this thesis reported on the performance of the FLS. A cohort study design allowed for the measuring of key performance indicators (KPIs) such as the rates of bone mineral density (BMD) investigation, treatment initiation, and follow-up participation over two years, as well as the incidence rate of subsequent fragility fractures. A secondary outcome was to longitudinally measure the change in bone biomarker levels and questionnaire scores using mixed-effect models. The second component of this work aimed to measure patterns of osteoporosis drug use with a cohort study design by reporting 1 and 2-year persistence rates and compliance levels (compliance being defined as a proportion of days covered (PDC) > 0.8). The third component of this thesis consisted in the identification of trajectory groups of compliance to follow-up care using group-based trajectory modelling (GBTM). The fourth and final component
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of this thesis was a cost-utility analysis using Markov decision analytic models to evaluate the economic impact of trajectory groups of compliance to follow-up care with respect to a usual care in a simulated cohort.
Results. Of the 532 fragility fracture patients that provided informed consent, 85.7% were female and the mean age was 63±11 years. First component: The FLS intervention yielded the following KPIs: BMD results were collected in almost 86% upon ordinance in the FLS, a prescription for anti-osteoporosis therapy was handed to > 86% of participants, 83.6% of subjects attended at least one follow-up visit (22.2% attended all visits) over two years, and the subsequent fracture incidence rate was of 2.6 per 100 person-years. Biomarker levels significantly decreased after six months in the FLS, supporting the inhibition of bone resorption induced by therapy. Questionnaire scores showed significant improvement of functional capacity over time (14%-64%). Second component: The one and two-year persistence rates were 66.4% and 55.6%, respectively. The proportions of patients with a one and two-year PDC > 0.8 were 64.2% and 62.5%, respectively. Third component: Through GBTM, three follow-up compliance trajectory groups were identified and consisted of high followers (HF, 48.4%), intermediate followers (IF, 28.1%) and low followers (LF, 23.5%). Fourth component: The incremental cost-utility ratios of the HF, IF and LF trajectory groups relative to usual care were $3,600, $22,000 and $74,000 per quality-adjusted life year gained, respectively.
Conclusions. A high-intensity FLS intervention with a systematic follow-up of fragility fracture patients allowed ongoing access to care over a two-year period. This resulted in high rates of investigation and treatment initiation, a low subsequent fracture rate, but follow-up participation could be improved over two years. More than half of the patients were persistent and compliant to therapy after two years. Almost half the cohort had a high compliance to follow-up care trajectory and this behaviour was found to be very cost-effective compared to usual care. The main limitation of this research program was the lack of a control group to assess effectiveness. A large pragmatic randomized controlled trial is needed to support these results. Further research should focus on understanding behaviours related to compliance to care using patient-centered outcomes, especially considering the high risk of fractures over time.
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Serviceability Behaviour of Reinforced UHPFRC Tensile ElementsKhorami, Majid 03 April 2023 (has links)
Tesis por compendio / [ES] Todas estructuras, especialmente las conformadas con hormigón armado, no solo deben cumplir con la seguridad necesaria bajo los Estados Límites Últimos (ULS), además es imprescindible que garanticen un comportamiento adecuado frente a condiciones de servicio. En general, los requisitos fundamentales de servicio que debe cumplir este tipo de estructuras son: la funcionalidad, comodidad para el usuario y la apariencia. Sin embargo, estos no se pueden verificar de forma directa; por lo tanto, ha sido necesario definir criterios de desempeño tales como control de deflexión, control de vibración y control de agrietamiento para dar cumplimiento a lo indicado anteriormente.
Además, se dificulta el cálculo de la capacidad de servicio debido al fenómeno de agrietamiento, el efecto de rigidez por tensión, la contracción y los efectos de fluencia. Por lo tanto, el control de la fisuración en estructuras de hormigón armado generalmente se logra limitando la tensión en el refuerzo de acero y la matriz de hormigón. Siendo así que, en los diseños incluidos en códigos relevantes a hormigón, especifican la tensión máxima del refuerzo de acero después de la fisuración y el ancho máximo de fisura para los miembros estructurales de CR o FRC, no obstante los aspectos de capacidad de servicio del diseño para el hormigón reforzado con fibras de ultra alto rendimiento reforzado (R-UHPFRC), no han sido incluidos en los códigos o recomendaciones de UHPFRC.
A pesar de que se han realizado muchos esfuerzos en la investigación tanto experimental como teórica sobre el comportamiento de servicio de los elementos estructurales de CR o FRC durante las últimas décadas, para el R-UHPFRC se debe desarrollar aún más su conocimiento relacionado con los requisitos para el diseño de capacidad de servicio, incluyendo su comportamiento de tensión y agrietamiento.
En este marco, el objetivo principal de la presente tesis doctoral es evaluar el comportamiento de servicio de R-UHPFRC. Por tal razón, es fundamental realizar la evaluación del comportamiento de deformación y fisuración de los elementos de tracción R-UHPFRC. Para ello, se abordaron y cumplieron adecuadamente dos puntos principales. El primero, diseñar una metodología de prueba innovadora y adecuada para ejecutar los experimentos requeridos para este proyecto de doctorado. En segundo lugar, se llevó a cabo la evaluación de la respuesta de rigidez a la tensión y el comportamiento de agrietamiento del R-UHPFCR, que son parámetros primordiales para el diseño de capacidad de servicio. Para estudiar estos dos parámetros, se consideraron algunos parámetros importantes tales como: el efecto del volumen del contenido de fibra, el tipo de fibra, el efecto del tamaño, el efecto de la relación de refuerzo y el efecto de la contracción.
Finalmente, para evaluar los parámetros mencionados, se presentan cuatro campañas experimentales. Cada una de ellas, representa un nivel diferente de estudio. El primero corresponde a la validación de la metodología de ensayo de tracción propuesta y examinar los datos experimentales obtenidos, para emplearlos en futuros estudios de este proyecto. El segundo nivel consistió en establecer y realizar experimentos completos con dos tipos de fibra de acero, modificando además su cantidad, es así como se utilizaron diferentes proporciones de refuerzo y sección transversal para evaluar el efecto tanto del tamaño como del contenido de fibra, respectivamente. También, en un estudio experimental específico se indagó sobre el efecto de la combinación de micro y microfibras de acero en la deformación y el comportamiento de agrietamiento de los elementos R-UHPFRC de tracción. El tercer nivel corresponde a una prueba de contracción intensiva, necesaria para obtener el valor de contracción del UHPFRC utilizado en esta investigación. El último nivel comprende la modificación de la geometría de la probeta y el uso de probetas en forma de hueso de perro para evaluar el ancho medio y máximo de fisura (valor / [CA] Totes les estructures, especialment les conformades amb formigó armat, no només han de complir amb la seguretat necessària sota els Estats Límits Últims (ULS), a més és imprescindible que garanteixin un comportament adequat davant de condicions de servei. En general, els requisits fonamentals de servei que ha de complir aquest tipus d'estructures són: la funcionalitat, la comoditat per a l'usuari i l'aparença. Això no obstant, aquests no es poden verificar de forma directa; per tant, ha calgut definir criteris d'acompliment com ara control de deflexió, control de vibració i control d'esquerdament per a donar compliment al que s'ha indicat anteriorment.
A més, es dificulta el càlcul de la capacitat de servei a causa del fenomen d'esquerdament, l'efecte de rigidesa per tensió, la contracció i els efectes de fluència. Per tant, el control de la fissuració en estructures de formigó armat generalment s'aconsegueix limitant la tensió al reforç d'acer i la matriu de formigó. És així que en els dissenys inclosos en codis rellevants a formigó, especifiquen la tensió màxima del reforç d'acer després de la fissuració i l'amplada màxima de fissura per als membres estructurals de CR o FRC, no obstant els aspectes de capacitat de servei del disseny per al formigó reforçat amb fibres d'ultra alt rendiment reforçat (R-UHPFRC), no han estat inclosos als codis o recomanacions d'UHPFRC.
Tot i que s'han realitzat molts esforços en la investigació tant experimental com teòrica sobre el comportament de servei dels elements estructurals de CR o FRC durant les últimes dècades, per al R-UHPFRC s'ha de desenvolupar encara més el seu coneixement relacionat amb els requisits per al disseny de capacitat de servei, incloent el comportament de tensió i esquerdament.
En aquest marc, l'bjectiu principal de la present tesi doctoral és avaluar el comportament de servei de R-UHPFRC. Per aquesta raó, és fonamental fer l'avaluació del comportament de deformació i fissuració dels elements de tracció R-UHPFRC. Per això, es van abordar i van complir adequadament dos punts principals. El primer, dissenyar una metodologia de prova innovadora i adequada per executar els experiments requerits per a aquest projecte de doctorat. En segon lloc, es va fer l'avaluació de la resposta de rigidesa a la tensió i el comportament d'esquerdament del R-UHPFCR, que són paràmetres primordials per al disseny de capacitat de servei. Per estudiar aquests dos paràmetres, es van considerar alguns paràmetres importants com ara l'efecte del volum del contingut de fibra, el tipus de fibra, l'efecte de la mida, l'efecte de la relació de reforç i l'efecte de la contracció.
Finalment, per avaluar els paràmetres mencionats, es presenten quatre campanyes experimentals. Cadascuna representa un nivell diferent d'estudi. El primer correspon a la validació de la metodologia dassaig de tracció proposada i examinar les dades experimentals obtingudes, per a emprar-les en futurs estudis daquest projecte. El segon nivell va consistir a establir i realitzar experiments complets amb dos tipus de fibra d'acer, modificant-ne a més la quantitat, és així com es van utilitzar diferents proporcions de reforç i secció transversal per avaluar l'efecte tant de la mesura com del contingut de fibra, respectivament. També, en un estudi experimental específic, es va indagar sobre l'efecte de la combinació de micro i macrofibres d'acer en la deformació i el comportament d'esquerdament dels elements R-UHPFRC de tracció. El tercer nivell correspon a una prova de contracció intensiva, necessària per obtenir el valor de contracció de l'UHPFRC utilitzat en aquesta investigació. L'últim nivell comprèn la modificació de la geometria de la proveta i l'ús de provetes en forma d'os de gos per avaluar l'amplada mitjana i màxima de fissura (valor real detectat) provocat per esforços de tracció en els elements de tracció R-UHPFRC . És important esmentar que es van fer diferents anàlisis per a cada investigació experimental i es van ac / [EN] All structures, particularly reinforcement concrete structures, apart from meeting necessary security against Ultimate Limit States (ULS), must exhibit appropriate behaviour under service conditions. Generally, the fundamental serviceability requirements that concrete structures should meet are functionality, user comfort and appearance. These requirements cannot, however, be directly checked. Therefore, performance criteria, such as deflection control, vibration control and cracking control, are defined to meet these requirements.
Serviceability calculation is complicated because of the cracking phenomenon, the tension stiffening effect, shrinkage, and creep effects. Cracking control in reinforced concrete (RC) structures is generally achieved by limiting stress in steel reinforcement and the concrete matrix. Many concrete code designs specify a maximum steel reinforcement stress after cracking and a maximum crack width for RC or fibre-RC (FRC) structural members, while the design serviceability aspects for Reinforced Ultra-High Performance Fibre-Reinforced Concrete (R-UHPFRC) are poorly considered in UHPFRC codes or recommendations.
Many efforts have been made in experimental and theoretical research into the serviceability behaviour of RC or FRC structural elements in the last few decades. However, for R-UHPFRC, knowledge about tension and cracking behaviour must improve and serviceability design requirements have to be further studied.
Within this framework, the main purpose of the present PhD thesis is to evaluate the serviceability behaviour of R-UHPFRC. For this purpose, the evaluation of the deformation and cracking behaviour of R-UHPFRC tensile elements is essential. To that end, two main items were addressed and adequately met. The first one was to design an innovative and adequate test methodology to carry out the experiments required for this PhD project. The second involved evaluating the tension stiffening response and cracking behaviour of R-UHPFRC, which are fundamental parameters for R-UHPFRC structures' serviceability design. To study these two parameters, important parameters were considered, such as fibre content, fibre type, size effect, reinforcement ratio and shrinkage effect.
In order to evaluate the aforementioned parameters, four experimental campaigns are presented. Each campaign represents a different study level. The first corresponds to the validation of the proposed tensile test methodology and to the examination of the obtained experimental data for future studies required for this PhD project. The second experimental study level corresponds to establishing and undertaking comprehensive experimental programmes with two different steel fibre types and fibre contents. Different cross-section and reinforcement ratios were used to evaluate the size effect and fibre content effect, respectively. The effect of the micro- and macro-steel fibres combination on the deformation and cracking behaviour of tensile R-UHPFRC elements was investigated in a specific experimental study. The third level corresponds to an intensive shrinkage test, which was conducted to obtain the shrinkage value of the UHPFRC used in this PhD study. The final level corresponds to a specific experimental study, done by modifying the specimen's geometry and using the dog bone-shaped specimens to evaluate the average and maximum crack width (real detected value) caused by tensile stresses in R-UHPFRC tensile elements. It is worth mentioning that different analyses were performed for each experimental research and appropriate results were achieved to fulfil the thesis aims.
Keywords: cracking behaviour, design criteria, durability, fragility curve, post-cracking tensile stiffness, serviceability behaviour, shrinkage, SLS requirements, structural design, tensile elements, tension stiffening, test method, tie, UHPFRC. / This work is part of Project “BIA2016-78460-C3-1-R” supported by the State Research Agency of Spain / Khorami, M. (2023). Serviceability Behaviour of Reinforced UHPFRC Tensile Elements [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/192683 / Compendio
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Ultimate Limit States in Controlled Rocking Steel Braced FramesSteele, Taylor Cameron January 2019 (has links)
The Insurance Bureau of Canada released a report in 2013 that evaluated the seismic risk of two major metropolitan areas of Canada, with projected losses of $75bn in British Columbia along the Cascadia subduction zone, and $63bn in the east through the Ottawa-Montreal-Quebec corridor. Such reports should prompt researchers and designers alike to rethink the way that seismic design is approached in Canada to develop resilient and sustainable cities for the future. To mitigate the economic losses associated with earthquake damage to buildings in seismically active areas, controlled rocking steel braced frames have been developed as a seismically resilient low-damage lateral-force resisting system. Controlled rocking steel braced frames (CRSBFs) mitigate structural damage during earthquakes through a controlled rocking mechanism, where energy dissipation can be provided at the base of the frame, and pre-stressed tendons pull the frame back to its centred position after rocking. The result is a building for which the residual drifts of the system after an earthquake are essentially zero, and the energy dissipation does not result from structural damage. Design methods for the base rocking joint and the capacity-protected frame members in CRSBFs have been proposed and validated both numerically and experimentally. However, the is no consensus on how to approach the design of the frame members, questions remain regarding how best to design CRSBFs to prevent building collapse, and no experimental work has been done regarding how to connect the CRSBF to the rest of the structure to accommodate the rocking motion.
Because the force limiting mechanism of a CRSBF is rocking only at the base of the frame, the frame member forces are greatly influenced by the higher-mode response, resulting in more complex methods to design the frame members. This thesis begins by outlining two new design procedures for the frame members in controlled rocking steel braced frames that target both simplicity and accuracy. The first is a dynamic procedure that requires a truncated response spectrum analysis on a model of the frame with modified boundary conditions to consider the rocking behaviour. The second is an equivalent static procedure that does not require any modifications to the elastic frame model, instead using theory-based lateral force distributions to consider the higher modes of the rocking structure. Neither method requires empirical calibration to estimate the forces at the target intensity.
The base rocking joint design is generally in good agreement between the various research programs pioneering the development of the CRSBFs. However, the numerous parameters available to select during the design of the base rocking joint give designers an exceptional amount of control over the performance of the system, and little research is available on how best to select these parameters to target or minimise the probability of collapse for the building. This thesis presents a detailed numerical model to capture collapse of buildings with CRSBFs as their primary lateral force resisting system and uses this model to generate collapse fragility curves for different base rocking joint design parameters. The parameters include the response modification factor, the hysteretic energy dissipation ratio, and the post-tensioning prestress ratio. This work demonstrates that CRSBFs are resilient against collapse, as designing the base rocking joint with response modification factors as large as 30, designing the post-tensioning to prevent yielding at moderate seismic hazard levels, and using zero energy dissipation could lead to designs with acceptable margins of safety against collapse.
While the design procedures are shown to be accurate for estimating the frame member force demand for the targeted intensity level, there is still a high level of uncertainty around what intensity of earthquake a building will experience during its lifespan, and there is no consensus on what intensity should be targeted for design. To address this, the ability of the capacity design procedures to provide a sufficiently low probability of collapse due to excessive frame member buckling and yielding is evaluated and compared to the probability that the building will collapse due to excessive rocking of the frame. The results of the research presented here suggest that the probability of collapse due to either frame member failure or excessive rocking should be evaluated separately, and that targeting the intensity with a 10% probability of exceedance in 50 years is sufficient for the design of the frame members.
Finally, critical to the implementation of CRSBFs in practice is how they may be connected to the rest of the structure to accommodate the uplifting of the CRSBF while rocking under large lateral forces. An experimental program was undertaken to test three proposed connection details to accommodate the relative uplifts and forces. The connections that accommodate the uplifts through sliding performed better than that which accommodated the uplifts though material yielding, but the best way to transfer the forces and accommodate the uplifting without influencing the overall behaviour of the system is to position the connection such that it does not need to undergo large uplifts and carry lateral force simultaneously. A detailed numerical model of the experimental setup is presented and is shown to simulate the important response quantities for each of the tested connections.
Using the results of this work, designers worldwide will be confident to design CRSBFs for structures from the base rocking joint to the selection of floor-to-frame connections for a complete system design while ensuring a safe and resilient building structure for public use and well-being. / Thesis / Doctor of Philosophy (PhD) / Traditional approaches to seismic design of buildings have generally been successful at preventing collapse and protecting the lives of the occupants. However, the buildings are often left severely damaged, often beyond repair. To address these concerns, controlled rocking steel braced frames have been proposed as part of a new construction technique to mitigate or prevent damage to steel buildings during earthquakes, but several aspects of the design and overall safety have yet to be explored or demonstrated. This thesis proposes and validates new tools to design controlled rocking steel braced frames and provides recommendations on how best to design them to achieve a safe probability against collapse. Details are proposed and presented for components to connect the controlled rocking steel braced frames into the rest of the structure. The findings of this thesis will aid practitioners looking to deliver resilient and sustainable structural designs for buildings in our cities of the future.
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The effects of financial liberalisation in emerging market economiesChauhan, Shobha 01 1900 (has links)
The aim of this research is to show the effects of financial liberalisation on emerging market economies, how these economies removed restrictions on financial institutions so that they can be globally integrated, and to show the flow of international finance in and out of a country. This research also illustrates how the financial system in these economies moved from being government-led to being market-led. The main finding of this research is that many countries failed to reap the benefits of liberalisation because of weaknesses in the regulatory structure, undercapitalised banks, volatile markets and contagion effects. The research concludes that the long-term gains of liberalisation certainly supersede short-term instability of liberalisation. Thus, for financial liberalisation to have predominantly positive effects, attention should be drawn to the importance of a more prudent regulatory and supervisory environment. Furthermore, financial liberalisation must be accompanied by a sound institutional infrastructure, proper conduct of monetary and fiscal policies, a reduction in corruption, and an increase in transparency. In addition, liberalisation should be a gradual process whereby the right measures are taken in the right sequence. / Economics / M. Comm. (Economics)
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Behaviour of three-dimensional concrete structures under concurrent orthogonal seismic excitationsZaghlool, Baher SalahElDeen Othman Ahmed January 2007 (has links)
This thesis is a study into the response and seismic safety of three-dimensional multi-storey concrete structures under concurrent orthogonal seismic excitations. It employs the nonlinear time-history method as its analysis tools. Time-history analyses rely heavily on their utilised earthquake records. Accordingly, this study examines the different approaches of selecting earthquake suites and develops a methodology of selecting representative earthquake scenarios. This methodology is credibly implemented in selecting a far- and a near field suites representative of the New Zealand seismic hazard. The study investigates the response of 6-, 9- and 12-storey concrete structures of different n-X-bays × m-Y-bays. Bidirectional responses of these considered structures are examined and consequently the current combination rules are scrutinised. Consequently this study strongly recommends the use of the 40-percent combination rule in lieu of the widely used 30-percent rule; and the use of time-history analysis in lieu of quasi/equivalent static and response modal analysis methods to avoid their strong dependence on combination rules. An intensive study is conducted employing the incremental dynamic analysis (IDA) technique to investigate structural demands of interstorey drifts, lateral storey drifts and storey accelerations. The study utilises the developed far-field suite and identifies the 50th and 90th percentile demands. Hence it provides easy-to-use expressions to facilitate rapid calculation of the structural demands and the effects of biaxial interactions. An implementation into the Demand and Capacity Factor Design (DCFD) format is presented that infers confidence in the performance levels of the considered structures. The study also draws attention to the importance of considering storey accelerations as their storey values reach as high as 10 × PGA. A sensitivity study is conducted by repeating the IDA investigation while using the developed near-field suite. Subsequently a comparison between the near- and the far-field results is conducted. The results were markedly similar albeit of less magnitudes until the (seismic hazard) intensity measure IM = Sa(T₁) = 0.4g when the near-field results show sudden flat large increase in demands suggesting a brittle collapse. This is attributed to the higher content of the higher mode frequencies contained in near-field ground motions. Finally, the study examines the (vectorial) radial horizontal shear demands in columns and beam-column joints of the previous far- and near-field studies. The combined radial shear demands in corner, edge and internal columns and joints are evaluated that roughly show a square-root proportional relationship with IM that exhibit somewhat brittle failure at IM ≥ 0.35g. Shears demands in the (4-way) internal columns and the (2-way) corner joints show highest magnitude in their respective class. The results suggest transverse joint shear reinforcement of 1.5, 1.0 and 0.5 of the longitudinal reinforcement of the neighbouring beam respectively for corner, edge and internal joints. An implementation of a proposed practical (and simpler) DCFD format shows satisfactory confidence in columns performance in shear up to IM = 0.35g, conversely to joints unsatisfactory performance in shear at the onset of inelastic behaviour (IM > 0.05g).
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Experimental and numerical studies of masonry wall panels and timber frames of low-rise structures under seismic loadings in IndonesiaSusila, Gede Adi January 2014 (has links)
Indonesia is a developing country that suffers from earthquakes and windstorms and where at least 60% of houses are non-engineered structures, built by unskilled workers using masonry and timber. The non-engineered housing units developed in urban region are also vulnerable to seismic hazard due to the use of low quality of material and constructions method. Those structures are not resistant to extreme lateral loads or ground movement and their failure during an earthquake or storm can lead to significant loss of life. This thesis is concerned with the structural performance of Indonesian low-rise buildings made of masonry and timber under lateral seismic load. The research presented includes a survey of forms of building structure and experimental, analytical and numerical work to predict the behaviour of masonry wall and traditional timber frame buildings. Experimental testing of both masonry and timber have been carried out in Indonesia to establish the quality of materials and to provide material properties for numerical simulations. The experimental study found that the strength of Indonesia-Bali clay brick masonry are below the minimum standard required for masonry structures built in seismic regions, being at least 50% lower than the requirement specified in British Standard and Eurocode-6 (BS EN 1996-1-1:2005). In contrast, Indonesian timber materials meet the strength classes specified in British Standard/Eurocode- 5 (BS EN 338:2009) in the range of strength grade D35-40 and C35).Structural tests under monotonic and cyclic loading have been conducted on building components in Indonesia, to determine the load-displacement capacity of local hand-made masonry wall panels and timber frames in order to: (1) evaluate the performance of masonry and timber frame structure, (2) investigate the dynamic behaviour of both structures, (3) observe the effect of in-plane stiffness and ductility level, and (4) examine the anchoring joint at the base of timber frame that resists the overturning moment. From these tests, the structural ductility was found to be less than two which is below the requirement of the relevant guidelines from the Federal Emergency Management Agency, USA (FEMA-306). It was also observed that the lateral stiffness of masonry wall is much higher than the equivalent timber frame of the same height and length. The experimental value of stiffness of the masonry wall panel was found to be one-twelfth of the recommended values given in FEMA-356 and the Canadian Building code. The masonry wall provides relatively low displacement compared to the large displacement of the timber frame at the full capacity level of lateral load, with structural framing members of the latter remaining intact. The weak point of the timber frame is the mechanical joint and the capacity of slip joint governs the lateral load capacity of the whole frame. Detailed numerical models of the experimental specimens were setup in Abaqus using three-dimensional solid elements. Cohesive elements were used to simulate the mortar behaviour, exhibiting cracking and the associated physical separation of the elements. Appropriate contact definitions were used where relevant, especially for the timber frame joints. A range of available material plasticity models were reviewed: Drucker-Prager, Crystalline Plasticity, and Cohesive Damage model. It was found that the combination of Crystalline Plasticity model for the brick unit and timber, and the Cohesive Damage model for the mortar is capable of simulating the experimental load-displacement behaviour fairly accurately. The validated numerical models have been used to (1) predict the lateral load capacity, (2) determine the cracking load and patterns, (3) carry out a detailed parametric study by changing the geometric and material properties different to the experimental specimens. The numerical models were used to assess different strengthening measures such as using bamboo as reinforcement in the masonry walls for a complete single storey, and a two-storey houses including openings for doors and windows. The traditional footing of the timber structures was analysed using Abaqus and was found to be an excellent base isolation system which partly explains the survival of those structures in the past earthquakes. The experimental and numerical results have finally been used to develop a design guideline for new construction as well as recommendations for retrofitting of existing structures for improved performance under seismic lateral load.
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The effects of financial liberalisation in emerging market economiesChauhan, Shobha 01 1900 (has links)
The aim of this research is to show the effects of financial liberalisation on emerging market economies, how these economies removed restrictions on financial institutions so that they can be globally integrated, and to show the flow of international finance in and out of a country. This research also illustrates how the financial system in these economies moved from being government-led to being market-led. The main finding of this research is that many countries failed to reap the benefits of liberalisation because of weaknesses in the regulatory structure, undercapitalised banks, volatile markets and contagion effects. The research concludes that the long-term gains of liberalisation certainly supersede short-term instability of liberalisation. Thus, for financial liberalisation to have predominantly positive effects, attention should be drawn to the importance of a more prudent regulatory and supervisory environment. Furthermore, financial liberalisation must be accompanied by a sound institutional infrastructure, proper conduct of monetary and fiscal policies, a reduction in corruption, and an increase in transparency. In addition, liberalisation should be a gradual process whereby the right measures are taken in the right sequence. / Economics / M. Com. (Economics)
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The challenges experienced by white teachers in the transition to democracy / Uitdagings wat deur wit onderwysers in die oorgang na demokrasie ervaar word / Imingeni ejongene nootitshala abamhlophe kwixesha lenguqu yedemokhrasiLosch, Juanita Judith 11 1900 (has links)
Abstracts in English, Afrikaans and Xhosa / This research aimed at investigating the challenges white teachers face in the socialisation of diverse learners in a former Model C school in the northern suburbs of Cape Town. The research involved a literature review conceptualising democracy, human rights, diversity, equality and socialisation, in addition to the concepts of white fragility and the theoretical perspective of Bourdieu’s ‘habitus’. The empirical investigation consisted of interviews to gather data. The findings revealed the perspectives of the teachers and their understanding of the socialisation of diverse learners in a democracy. Based on these findings, recommendations were made for the school and the Department of Basic Education to develop a system to incorporate in schools, in order to enhance socialisation and the transformation of former Model C schools.
As the title states, this study was focused on the challenges white teachers experience relating to the transition to democracy. The context of a former Model C school is a complex scenario, where the values and norms of a dominant culture have formed, and continue to form, a critical part of the school climate and culture. The research findings revealed that since the transformation process started in 1994, ‘ex-Model C’ schools have assumed different characteristics and encountered challenges depending on their demographical location. Teachers need to address both social and educational aims, especially as the findings suggest that the schools, and particularly the teachers, are unclear about how diversity contributes to norms and values. This reflects in the tendency to remain focused on a dominant white culture, with which the teachers identify as ‘normal’. / Hierdie navorsing het ten doel gehad om die uitdagings wat wit onderwysers ten opsigte van die sosialisering van diverse leerders in ʼn gewese model C-skool in die noordelike voorstede van Kaapstad trotseer, te ondersoek. Die navorsing het ʼn literatuuroorsig behels waarvolgens demokrasie, menseregte, diversiteit, gelykheid en sosialisering gekonseptualiseer word, benewens die konsepte van wit broosheid en die teoretiese perspektief van Bourdieu se “habitus”. Die empiriese ondersoek het bestaan uit onderhoude om data in te samel. Die bevindinge het onderwysers se perspektiewe en hul begrip van die sosialisering van diverse leerders in ʼn demokrasie onthul. Op grond van hierdie bevindinge is aanbevelings gedoen vir die skool en die Departement van Basiese Onderwys rakende die ontwikkeling van ʼn stelsel om in skole te inkorporeer ten einde sosialisering en die transformasie van gewese model C-skole te bevorder.
Soos wat die titel aandui, het hierdie studie gefokus op die uitdagings wat wit onderwysers ervaar ten opsigte van die oorgang na demokrasie. Die konteks van ʼn gewese model C-skool is ʼn komplekse scenario, waar die waardes en norme van ʼn dominante kultuur ʼn noodsaaklike deel van die skoolklimaat en -kultuur gevorm het (en dit is steeds die geval). Die navorsingsbevindinge het getoon dat sedert die transformasieproses in 1994 begin het, “eks-model C”-skole verskillende eienskappe aangeneem het en uitdagings teëgekom het afhangende van hul demografiese ligging. Onderwysers moet sowel sosiale as opvoedingsdoelwitte bereik, veral aangesien die navorsingsresultate daarop dui dat daar onduidelikheid onder die skole, en veral die onderwysers, is oor hoe diversiteit bydra tot norme en waardes. Dit blyk uit die neiging om gefokus te bly op ʼn dominante wit kultuur waarmee die onderwysers identifiseer as “normaal”. / Olu phando lujolise ekuphandeni imingeni ejongene nootitshala abamhlophe ekuhlanganiseni ngokwezentlalo abafundi beentlanga ezahlukeneyo kwisikolo esasifudula siyiModel C kumahlomela edolophu asemantla esixeko saseKapa. Uphando lwenza uphononongo loluncwadi oluchaza ngedemokhrasi, amalungelo oluntu, ukungafani, ulingano noqheliso lwezentlalo, kwakunye nobuthathaka babamhlophe neenkalo zokucinga ngokwethiyori ka Bourdieu ekuthiwa yi’habitus’. Uphando olusekelwe kubungqina baquka iindliwano ndlebe ekuqikeleleni idatha. Okufunyanisiweyo kwadiza iimbono zootitshala nendlela abaluqonda ngayo uqheliso lwezentlalo lwabafundi abangafaniyo kwimeko yedemokhrasi. Okufunyanisiweyo kwakhokelela ekwenziweni kweengcebiso kwisikolo nakweSebe Lemfundo Esisiseko ukuba kuphuhliswe inkqubo yokubandakanya ezikolweni, ngenjongo yokukhulisa uqheliso lwezentlalo nenguqu yezikolo ezazifudula ziziModel C.
Njengoko nesihloko sisitsho, esi sifundo sagxininisa kwimingeni ejongene nootitshala kwixesha lenguqu eya kwidemokhrasi. Imeko yesikolo esasifudula siyiModel C yimeko enzima, apho iinqobo zokucinga nezithethe zenkcubeko eyongameleyo zibumbe, kwaye zisaqhuba ukubumba inxalenye emandundu yesimo sentlalo nenkcubeko yesikolo. Okufunyaniswe kuphando kwadiza ukuba okoko kwaqala inkqubo yenguqu ngowe-1994, izikolo ezazifudula ziziiModel C zaba neempawu ezahlukileyo kwaye zajongana nemingeni ngokuxhomekeke kwiindawo ezimi kuzo. Ootitshala badinga ukuhlangabeza iinjongo zentlalo nemfundo, ngakumbi, ngokokutsho kophando, izikolo, ngakumbi ootitshala, bengacacelwanga kukuba ukungafani kuncedisa njani kwiinqobo zokucinga nezithethe. Oku kubonakala kumkhwa wokungagungqi kwinkcubeko yabamhlophe neyongameleyo, le ootitshala bayithatha ngokuba ‘yeyesiqhelo’. / Educational Studies / M. Ed. (Socio-Education)
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I classici attraverso l'Atlantico: la ricezione dei Padri Fondatori e Thomas Jefferson / CLASSICS ACROSS THE ATLANTIC: THE FOUNDERS' RECEPTION AND THOMAS JEFFERSONBENEDETTI, MARTA 17 March 2016 (has links)
La tesi si occupa di verificare l’influenza che i classici greci e latini hanno esercitato su i padri fondatori americani e più in particolare su Thomas Jefferson. La prima sezione tratteggia il contesto universitario e lo studio delle lingue classiche tra seicento e settecento, comprendendo non solo le università inglesi (Oxford e Cambridge) e scozzesi, ma anche i nuovi college nati nelle colonie americane. Tale analisi dei modelli e delle pratiche educative ha permesso, in effetti, di comprendere meglio l’influenza dei classici sui rivoluzionari americani. Nello specifico viene scandagliata a fondo l’educazione ricevuta da Jefferson. Tra i numerosi spunti di studio aperti da codesto argomento, il lavoro si concentra sulle modalità con cui i classici gli furono insegnati, sul suo Commonplace Book (una raccolta di brani tratti in parte da autori antichi letti in giovinezza) e su documentazione epistolare. Quest’ultima è oggetto particolare di studio, allo scopo di scoprire quali opere antiche Jefferson, in età adulta e durante la vecchiaia, lesse e apprezzò. Essendo un collezionista di libri, comprò moltissimi testi classici come dimostrano alcuni suoi manoscritti.
Nonostante manchino dati precisi a riguardo, risulta inoltre che Jefferson, benché facesse largo uso di traduzioni, preferiva leggere in originale e che probabilmente abbia letto la maggior parte di questi libri durante il ritiro dalla vita politica.
La seconda parte della tesi si concentra, invece, a indagare quanto la sua educazione classica abbia contributo alla formazione della sua personalità e delle sue idee, nonché alla forma stessa del suo pensiero in merito ad alcune tematiche. Lo studio è di conseguenza dedicato all’esperienza umana di Jefferson, in particolare alla sua riflessione sulla morte e sull’eternità, temi fortemente legati alla sua ricezione di idee epicuree e stoiche. Epicureismo e Stoicismo rappresentano, in definitiva, i due sistemi filosofici antichi che hanno maggiormente influenzato la sua personalità e il suo pensiero. / The aim of the present work is to evaluate the impact of the ancient classics on the American Founding Fathers, with a particular focus on Thomas Jefferson.
The first section gives a wide portrait of the academic context in which the Founders were educated, comprising not only of Oxford, Cambridge, and the Scottish universities, but also the colonial colleges. The evaluation of the educational practices in use at the time makes it possible to understand better the classical impact on revolutionary Americans. In particular, this analysis studies in depth Jefferson's education. Of the many possible perspectives and approaches to this topic, the present work focuses on the way ancient classics were taught to him, his Commonplace Book, which reports part of the ancient classics he read during his youth, and his correspondence. The latter has been studied especially to understand which other ancient writers he read, valued, and esteemed in his adulthood and old age.
As book collector, Jefferson bought an incredible number of ancient classics, as attested by a few manuscripts of his book lists. Despite the dearth of sure evidence, it is very likely that he read the ancient works largely during his retirement. He loved reading them in the original, though he made great use of translations.
The second part of this work is dedicated to investigating how Jefferson's classical education contributed to the building of his personality and ideas, as well as how he elaborated specific classical themes in his own life. The study is thus focused on Jefferson's personal human experience, specifically on his reflection on human mortality and the afterlife. These themes, indeed, are strictly linked to his reception of Epicurean and Stoic tenets, the two ancient philosophical systems which had the greatest and most profound impact on Jefferson's personality and thought.
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