The performance of nonstructural components in critical infrastructure, such as nuclear power plants (NPPs), has been primarily based on experience and historical data. This topic has been attracting increased interest from researchers following the Fukushima Daiichi nuclear disaster in 2011. This disaster demonstrated the importance of using batteries in NPPs as an auxiliary power system, where such systems can provide the necessary power to mitigate the risk of serious accidents. However, little research has been conducted on such nonstructural components to evaluate their performance following the post- Fukushima safety requirements, recommended by several nuclear regulators worldwide [e.g., Nuclear Regulatory Commission (NRC), and Nuclear Safety Commission (NSC)]. To address this research gap, this dissertation investigates the lateral performance of an auxiliary battery power system (ABPS) similar to those currently existing/operational in NPPs in Canada. The ABPS was experimentally tested under displacement-controlled quasi-static cyclic fully-reversed loading that simulates lateral seismic demands. Due to the presence of sliding batteries, the ABPS was then tested dynamically under increased ground motion levels on a shake table. The experimental results demonstrated that the design guidelines and fragility curves currently assigned to battery rack systems in the FEMA P58 prestandards do not encompass all possible failure mechanisms. A 3D numerical model was also developed using OpenSees software. The model was validated using the experimental results. The model results showed that the lateral performance of ABPS with different configurations (i.e. different lengths, tiers, and seismic categories) is influenced by the capacity of the L-shaped connection between the side rails and the end rail. However, the model was not able to predict all the damage states from the dynamic experimental tests, since the rocking/sliding/impact behavior of the batteries is a highly complex nonlinear problem by nature and beyond the scope of this study. The model presented is limited to the assessment of the lateral performance of different ABPS statically. This dissertation demonstrated the difference between the observed behavior of laboratory-controlled lateral performance tests of ABPSs operational/existing in NPPs and the behavior of ABPSs found in the literature that relied on limited historical and experience data. Finally, this dissertation laid the foundations for the need to further investigate the behavior of other safety-related components in NPPs and assess their compliance with new post-Fukushima design requirements. / Thesis / Doctor of Philosophy (PhD)

Environmental noise at high levels and inappropriate construction techniques used in conventional buildings in Brazil claim for a transition to better construction systems. Recently the Brazilian standard NBR 15575:2013 established for the first time parameters and criteria for residential building performance. In standard minimum requirements for sound insulation are given, for example for external walls and roof structures. This way it is of fundamental importance to have sound transmission loss data for diferente types of such elements at hand. Taking into account that there is very little information on the sound transmission loss of external walls of the light steel frame (LSF) type measurements of sound insulation of different vertical external LSF walls typically used in Brazil were carried out. Eighteen different LSF walls were mounted in the sound transmission measurement chamber of the Federal University of Santa Maria and measurements were carried out in accordance with ISO 10140:2010. Sound insulation was characterized by means of the sound reduction index R, the weighted sound reduction index Rw and the sound transmission class, making it possible to compare the sound insulation of the LSF walls with data from the literature. The LSF walls under investigation in this study used different materials such as OSB panels, cement boards, plaster boards, Smartside panels, PVC panels, XPS panels and magnesium oxide boards for the outer face. The influence of resilient channels and sponge tape, placed between the outer face and the metalic studes, were also evaluated. The sound insulation of the diferente LSF walls were found to be 43 dB ≤ Rw ≤ 50 dB and 45 dB ≤ STC ≤ 52 dB. Within the LSF walls measured the one which used magnesium oxide boards on the outer face showed to have the highest weight sound reduction index (Rw = 50 dB). Resilient channels, fabricated especially for this study, and sponge tape were able to provide an increase of Rw and STC up to 5 dB compared to the same wall without this resilient elements, and provide better sound insulation especially for frequencies higher than 400 Hz. From the data it can be concluded that LSF walls are more efficient regarding the sound insulation than single walls of the same surface mass and in some cases even better than single walls of superior surface mass, such as walls made of massive brick or concrete blocks. / O excesso de ruído ambiental e as inadequadas técnicas construtivas dos sistemas convencionais utilizados no mercado da construção civil brasileira, fazem com que seja necessária a introdução de novas tecnologias construtivas mais racionais e produtivas. A partir da entrada em vigor da NBR 15575:2013 foram estabelecidos diversos parâmetros de desempenho para edificações habitacionais. A referida norma também estabelece exigências mínimas de isolamento acústico para os sistemas que compõem as edificações, entre eles, as vedações verticais. Desta forma, informações sobre o isolamento acústico providenciado pelos diferentes sistemas construtivos tornaram-se de fundamental importância. Tendo em vista a pouca informação existente na literatura sobre o isolamento sonoro de paredes externas em light steel frame (LSF), foram realizadas medições de perda de transmissão sonora em paredes externas executadas neste sistema construtivo, usadas tipicamente no mercado brasileiro. Dezoito composições de paredes em LSF foram montadas na câmara reverberante de transmissão sonora da UFSM para realização dos ensaios de perda de transmissão conforme procedimentos propostos pela ISO 10140:2010. O isolamento sonoro foi quantificado a partir dos espectros do índice de redução sonora R, pelo índice de redução sonora ponderado Rw e pela classe de transmissão sonora STC, facilitando a comparação entre diferentes composições de parede e dados de isolamento sonoro encontrados na bibliografia. Os principais materiais utilizados no revestimento das paredes LSF foram paineis OSB, placas cimentícias, placas de gesso acartonado, réguas Smartside, réguas de siding vinílico, painéis XPS e placas de óxido de magnésio. A influência da utilização de barras resilientes e fitas de espuma de PVC, entre as placas de revestimento e a estrutura metálica, também foi avaliada. Determinou-se que o isolamento sonoro das diferentes paredes LSF avaliadas é de 43 dB ≤ Rw ≤ 50 dB e 45 dB ≤ STC ≤ 52 dB. Dentre as paredes externas em LSF, aquela que utilizou placas de óxido de magnésio na face exterior apresentou o maior Rw = 50 dB. As barras resilientes e fitas de espuma de PVC foram capazes de aumentar o Rw e STC em até 5 dB, se comparado à parede semelhante sem estes dispositivos, especialmente nas frequências a partir de 400 Hz. A partir da análise dos dados, concluiu-se que as paredes LSF consideradas paredes duplas são mais eficientes no isolamento sonoro quando comparadas às paredes simples ou homogêneas de mesma massa e até do que algumas paredes com massa muito superior, como paredes de tijolos maciços, de blocos de concreto ou de blocos cerâmicos.

This thesis contains a design of a steel structure of two-bay industrial hall with an administrative facility in the city of Brno. There are 3 variants of solution for industrial steel hall with duopitch roof with overall dimensions 60x74 m and detailed structural analysis of the first variant. Height of the hall is 10,5 m. Main structure of the roof is designed as frames from steel profiles with purlins from cold rolled sections, a span of frames is 30 m. The material of main frames is steel S355, material of purlins is S450. The hall is equipped by overhead crane with loading capacity 5 tons. Bolted connections will be done with maximal stiffness and feasibility of the structure. The administrative facility is designed as an independent building with 3 floors, the floor plan is semicircular with diameter 48 m.

The thesis deals with the analysis and standard check of structural steel connections subjected to seismic loads. Analysis is based on a software solution and standard check is performed according to standard requirements and formulas. The first part deals with the theory of seismic load. There are described the general knowledges about the earthquake and the method of determining the effects of seismic loading on buildings according to the EN 1998-1. In the second part of the thesis is made design and check seismically loaded multi-storey steel building. Design is based on recommendations of the EN 1998-1 and some recommendations of research. In the third part is the analysis, verification and check of steel joints, which are contained in the structure designed in the second part of the thesis. On the basis results of analyses of indivudual connections are defined recommendations and requirements for the use and design structural steel connections subjected to seismic loads.

The subject of the final thesis is timber footbridge for pedestrians and cyclists over the Desna river in Loucna nad Desnou village. The length of the footbridge is 30 m, width 3 m and height is variable from 4 to 5 m. The footbridge is covered with roof inclination of 20° in transverse direction and the roof is arch in longitudinal direction. Roofing is metal sheet. The structure is three-dimensional truss consists of two truss connected by rafters, floor beams and by members of bracing. The 2D-truss consists of bottom chord, top arch chord and webs. There are end posts made of streel bracing frames. The material of structure is mostly glued laminated timber, then timber and steel. The steel is used for connectors and steel bracing frames.

CE-märkta stålbalkar byggdes in i två konstruktioner innan det upptäcktes att det fanns porer i hattbalkarnas svets. Den defekta svetsen innebar att byggnadernas bärförmåga inte kunde garanteras. Kunskapen kring inbyggt stål stommaterial med defekt svets är liten. Det är dessutom svårt att reparera och undersöka stålbalkarnas svets när de är inbyggda i konstruktionen. Syftet med examensarbetet är att hitta förstärkningsmetoder och därmed främja kortare hanteringstid vid händelse av att defekta stålbalkar byggs in i en konstruktion. Metoden består av litteraturstudie och intervjuer. Först granskas litteratur för att förstå problematiken med defekt svets i stål stommaterial. Därefter utförs intervjuer med personer erfarna inom stål och byggteknik. Examensarbetets resultat är ett flertal förstärkningsmetoder för inbyggda stålbalkar med defekt svets. Några av förstärkningsmetoderna är möjliga att utföra med den kunskap som finns idag medan andra behöver undersökas och värderas innan de kan implementeras. Förstärkningsmetoderna som är möjliga att utföra med dagens kunskap är: att svetsa om balken från insidan eller att placera en balk/fackverksbalk under den befintliga balken. De metoder som behöver undersökas och värderas vidare är: skruvförband genom balken, efterspänna balken med vajrar eller GWS-stag och sedan fylla den med betong, föra in en balk inne i balken och fylla balken med betong och att kolfiberförstärka svetsen. Slutsatsen är att den här studien kan ligga till grund för framtagning av åtgärder för inbyggda stålbalkar med defekt svets med mål att uppnå den dimensionerade hållfastheten och en lösning som är tidseffektiv, kostnadseffektiv och har låg klimatpåverkan. / Before the discovery of pores in the weld, CE-certified steel beams were embedded in two constructions. Since the weld was defective, the carrying capacity of the two buildings was questioned. There is a lack of knowledge about embedded steel beams with a damaged weld. It is difficult to repair and analyze the weld when the beams are embedded in the construction. The aim of the study is to find reinforcement methods for steel beams. The expectation is to shorten time in the production in case that defective steel beams are detected in the construction. The method consists of a literature study complemented by interviews. Literature is examined to understand the problem of defective welding in the steel framework. Subsequently, interviews are conducted with professionals within steel and building technology. The result of the report is multiple reinforcement methods for embedded steel beams with a defective weld. Some of the methods are possible to implement with the knowledge available today. Other methods need to be examined and assessed before executed. The reinforcement methods that are possible to perform are: weld the beam from the inside or place a beam underneath the existing beam. The methods that need further analysis are: drill a screw joint through the beam, strain the beam with steel-wires and fill the inside with concrete, place a beam inside the existing beam and fill the inside with concrete and last to reinforce the weld with carbon fibers. The conclusion is that this study can be used when reinforcement methods are needed for embedded steel beams with a defective weld. The objective with these methods is to restore the load-bearing capacity as well as finding a solution that is time efficient, economic and has low climatic influence.

As typically designed, the beam-column-brace connections of buckling-restrained braced steel frames have undesirable failure modes that compromise the integrity and performance of the frames and are costly to repair. To decrease the time and resources needed to repair the frames following an earthquake, a new connection design was developed that attempts to confine yielding to replaceable frame components. The design incorporates a gap in the beam beyond the edge of the beam-gusset weld that acts as a hinge and reduces moment forces transferred to the connection; it is bridged by splice plates that are bolted to the beam top flanges. The splice plates and buckling-restrained braces are the only frame components that are expected to yield. To investigate the performance of the proposed connection design, a prototype bay was designed and two test specimens were fabricated and tested. Each specimen represented a corner of the prototype braced bay and consisted of a beam, column, gusset plate, brace core extension assembly, splice plates, and lateral bracing angles. Both standard design procedures and newly developed criteria were used to design the connection. In preparation for testing, a method was developed for estimating the hysteretic response of a buckling-restrained brace. By using this method to program an actuator, the specimens could be tested without using actual braces, resulting in a significant reduction in testing cost. Testing was conducted using two 600 kip actuators; the first followed a static loading protocol with a maximum design drift of 6.5%, and the second replicated the prototype BRB's response. The tests yielded promising results: both specimens withstood the maximum displacements and avoided yielding in the beams, columns, and gusset plates; yielding did occur in the splice plates and BRB core extension assembly, as anticipated. Possible limitations in the design may arise under the presence of increased shear loads, concrete floor slabs, or out-of-plane loading. Additional testing is recommended.

La conception des ouvrages en Génie Civil se fait habituellement de manière semi-probabiliste en employant des valeurs caractéristiques auxquelles sont associées des facteurs partiels de sécurité. Toutefois, de telles approches ne permettent pas de garantir la robustesse de l’ouvrage conçu vis-à-vis des sources d’incertitudes susceptibles d’affecter ses performances au cours de sa réalisation et de son fonctionnement. Nous proposons dans ce mémoire une méthodologie d’aide à la décision pour la conception robuste des ouvrages qui est appliquée à une structure métallique reposant sur des fondations superficielles. La conception de cet ouvrage est conduite en intégrant le phénomène d’interaction sol-structure qui implique que les choix de conception faits sur la fondation influencent ceux faits sur la structure supportée (et réciproquement). La démarche de conception proposée fait appel à des outils d’optimisation multi-objectif et d’aide à la décision afin d’obtenir une solution qui offre le meilleur compromis entre l’ensemble des préférences énoncées par le décideur sur chaque critère de conception. Des analyses de sensibilité sont menées parallèlement dans le but d’identifier et de quantifier les sources d’incertitude les plus influentes sur la variabilité des performances de l’ouvrage. Ces sources d’incertitude représentées sous une forme probabiliste sont intégrées dans la procédure de conception et propagées à l’aide d’une méthode d’échantillonnage par hypercube latin. Une partie du mémoire est consacrée à l’analyse des effets de l’incertitude relative à la modélisation des paramètres géotechniques sur la réponse de l’ouvrage et sur la démarche plus globale d’optimisation. / Design in Civil Engineering is usually performed in a semi-probabilistic way using characteristic values which are associated with partial safety factors. However, this approach doesn’t guarantee the structure robustness with regard to uncertainties that could affect its performance during construction and operation. In this thesis, we propose a decision aid methodology for robust design of steel frame on spread foundations. Soil-structure interaction is taken into consideration in the design process implying that the design choices on foundations influence the design choices on steel frame (and vice versa). The proposed design approach uses multi-objective optimization and decision aid methods in order to obtain the best solution with respect to the decision-maker’s preferences on each criterion. Furthermore, sensitivity analyzes are performed in order to identify and quantify the most influencing uncertainty sources on variability of the structure performances. These uncertainties are modeled as random variables and propagated in the design process using latin hypercube sampling. A part of this dissertation is devoted to the effects of uncertainties involved in soil properties on the structure responses and on the design global approach.

This master's thesis deals with the designing of the appropriate supporting steel structure footbridge for pedestrians. The footbridge is used to connect two separate buildings (buildings D and Z at the Faculty of Civil Engineering Brno University of Technology). Four variants have been designed about solutions supporting steel structure. The final variant was prepared in detail and was carried out static assessment of the individual elements and selected details. The main supporting structure of this variant are two trusses. Diagonals of these trusses are designed linkage system of Macalloy 460. Bridge deck is designed of composite steel a concrete board with crossbars. The footbridge is designed as simple beam with an overhanging end. Length span is 34.8 m, length overhanging ends is 5.8 meters. The total length of the footbridge is 40.6 meters. Width of footbridge is 2.8 meters. Free width is 2 meters. In the cross point with the axis of local road is height of footbridge above ground 4.43 meters. Next to the building Z, there is a footbridge stored on a concrete support, near the building D, the footbridge is stored on a steel frame of support. The footbridge is deposited on elastomeric bearings. The footbridge is being protected from the weather. The sheating of the building is designed by Wictec 60 system. The master's thesis also contains drawing documentation of the proposed solution.

Fires following earthquake (FFE) have historically produced enormous post-earthquake damage and losses in terms of lives, buildings and economic costs, like the San Francisco earthquake (1906), the Kobe earthquake (1995), the Turkey earthquake (2011), the Tohoku earthquake (2011) and the Christchurch earthquakes (2011). The structural fire performance can worsen significantly because the fire acts on a structure damaged by the seismic event. On these premises, the purpose of this work is the investigation of the experimental and numerical response of structural and non-structural components of steel structures subjected to fire following earthquake (FFE) to increase the knowledge and provide a robust framework for hybrid fire testing and hybrid fire following earthquake testing. A partitioned algorithm to test a real case study with substructuring techniques was developed. The framework is developed in MATLAB and it is also based on the implementation of nonlinear finite elements to model the effects of earthquake forces and post-earthquake effects such as fire and thermal loads on structures. These elements should be able to capture geometrical and mechanical non-linearities to deal with large displacements. Two numerical validation procedures of the partitioned algorithm simulating two virtual hybrid fire testing and one virtual hybrid seismic testing were carried out. Two sets of experimental tests in two different laboratories were performed to provide valuable data for the calibration and comparison of numerical finite element case studies reproducing the conditions used in the tests. Another goal of this thesis is to develop a fire following earthquake numerical framework based on a modified version of the OpenSees software and several scripts developed in MATLAB to perform probabilistic analyses of structures subjected to FFE. A new material class, namely SteelFFEThermal, was implemented to simulate the steel behaviour subjected to FFE events.