The current thesis focuses on estimating the damage levels and evaluating the out-of-plane behavior of fully-grouted reinforced masonry (RM) structural walls under blast loading, a load that they are typically not designed to resist. Twelve third-scale RM walls were constructed and tested under free-field blast tests. Three different reinforcement ratios and three different charge weights have been used on the walls, with scaled distances down to 1.7 m/kg1/3 and two different boundary conditions, to evaluate the walls’ performances. In general, the results show that the walls are capable of withstanding substantial blast load levels with different extents of damage depending on their vertical reinforcement ratio and scaled distance. It worth mention that the current definitions of damage states, specified in ASCE/SEI 59-11 (ASCE 2011) and CAN/CSA S850-12 (CSA 2012) standards, involve global response limits such as the component support rotations that are relatively simple to calculate. However, these quantitative damage state descriptors can be less relevant for cost–benefit analysis. Moreover, the reported experimental results showed that the use of quantitative versus qualitative damage descriptors specified by North American blast standards [ASCE 59-11 (ASCE 2011) and CSA S850-12 (CSA 2012)] can result in inconstancies in terms of damage state categorization. Therefore, revised damage states that are more suitable for a cost–benefit analysis, including repair technique and building downtime, were presented. These damage states are currently considered more meaningful and have been used to quantify the post-earthquake performance of buildings. In addition, a nonlinear single-degree-of-freedom (SDOF) model is developed to predict the out-of-plane behavior of RM structural walls under blast loading. The proposed SDOF model is first verified using quasi-static and free-field blast tests and then subsequently used to extend the results of the reported experimental test results with different design parameters such as threat level, reinforcement ratio, available block width, wall height, and material characteristics. In general, brittle behavior was observed in the walls with a reinforcement ratio higher than 0.6%. This is attributed to the fact that seismically detailed structural masonry walls designed to respond in a ductile manner under in-plane loads might develop brittle failure under out-of-plane loads because of their reduced reinforcement moment arm. In addition, increased ductility can be achieved by using two reinforcement layers instead of a single layer, even if the reinforcement ratio is reduced. Also, it is recommended to consider the use of larger concrete masonry blocks for the construction of RM structural walls that are expected to experience blast loads in order to reduce the slenderness ratio and for the placement of two reinforcement layers. Finally, a probabilistic risk assessment (PRA) framework is proposed in order to develop design basis threat (DBT) fragility curves for reinforced concrete block shear wall buildings, which can be utilized to meet different probabilities of failure targets. To illustrate the proposed methodology, an application is presented involving a medium–rise reinforced masonry building, under different DBT levels. The DBT fragility curves are obtained via Monte Carlo sampling of the random variables and are used to infer the locations, within the building premises, that are most suitable for the erection of barriers for blast hardening. / Thesis / Doctor of Philosophy (PhD)

In this Master’s Degree project the topic of handheld deep cutting is analysed. These days in the construction business workers face the challenge of cutting into concrete, brick and other mineralbased materials deeper than 15 cm. Currently there are a few handheld solutions for deep cutting but they have some major limitations, such as low reliability and safety, high price, maintenance and tiresome usage of these machines. In this paper the project is divided into two components – market research and concept development. To build a knowledge base, firstly, current technical platforms for handheld deep cutting machines are reviewed. Then, theoretical background behind market research and concept development is analysed. Following theoretical framework market research and concept development are implemented and steps taken described. Secondary research, customer interviews and focus groups are the main sources of information for the market research. Morphological and Pugh’s matrices are then used to generate and evaluate possible concepts, while software packages SolidWorks and KeyShot are used as tools for development of design features. Findings from the market research revealed that window, door, ventilation openings, resizing of bricks or concrete elements and fixing mistakes done during moulding are the main applications of deep cutting machines. It was noticed that most of the construction professionals are not aware of these machines, use workarounds or hire subcontractors. Single-phase electric ring saw is the outcome from product concepting stage. Three design features – toothed ring, telescopic blade guard and start switch – are then proposed. Finally, discussion of the whole project and its conclusions are given, recommendations and short overview on future work are provided. Work consists of 7 parts: introduction, frame of reference, implementation, results, discussion and conclusions, recommendations and future work, references. Thesis consists of: 68 pages of text without appendixes, 40 figures, 4 tables, 35 references. 8 appendixes attached. / I detta masterprojekt analyseras ämnet handhållen djupskärning. Nuförtiden inom byggbranchen står arbetarna inför utmaningen att skära i betong, tegel och annat mineralbaserat material som är djupare än 15 cm. För närvarande finns det ett antal handhållna lösningar för djupskärning, dock med stora begränsningar så som låg pålitlighet och säkerhet, högt pris och behov av underhåll samt tröttsam användning av dessa maskiner. I detta arbete delas projektet upp i två komponenter – marknadsundersökning och konceptutveckling. För att bygga upp en kunskapsbas granskas först nuvarande tekniska plattformar för handhållna djupskärningsmaskiner. Därefter analyseras teoretisk bakgrund om marknadsundersökning och konceptutveckling. Baserat på det teoretiska ramverket, implementeras marknadsundersökningar och konceptutveckling och genomförandet beskrivs. Sekundär forskning, kundintervjuer och fokusgrupper är de primära informationskällorna för marknadsundersökningen. Morfologiska och Pughs matriser används sedan för att generera och utvärdera möjliga koncept, medan programen SolidWorks och KeyShot används som verktyg för utveckling av designfunktioner. Resultat från marknadsundersökningen visade att fönster, dörrar, ventilationsöppningar, storlekändringar på tegelstenar eller betongelement och korrigering av defekter som uppkommit under gjutning är de huvudsakliga användningsområdena för djupskärningsmaskiner. Det noterades att de flesta byggnadsarbetarna inte är medvetna om dessa maskiner, använder improviserade lösningar eller anlitar underleverantörer. Enfasig elektrisk ringsåg är resultatet av produktkonceptionsstadiet. Tre designdetaljer – tandad ring, teleskopskärmskydd och startbrytare – föreslås därefter. Slutligen presenteras diskussion om projektet och dess slutsatser samt rekommendationer och en kort översikt över framtida arbete. Arbetet består av 7 delar: introduktion, referensram, genomförande, resultat, diskussion och slutsatser, rekommendationer och framtida arbete, referenser. Avhandlingen består av: 68 sidor text utan bilagor, 40 figurer, 4 tabeller, 35 referenser. 8 bilagor bifogade.

[pt] A alvenaria é um material largamente utilizado, e é fundamental a realização de pesquisas para caracterizar seu desempenho e elevar a sua utilização a um aspecto mais estrutural, não apenas funcional (separação de ambientes). Neste trabalho é apresentada uma modelagem em elementos finitos para estruturas de alvenaria. Utilizando um modelo numérico sofisticado com base no Método dos Elementos Finitos, associado a um modelo constitutivo adequado, busca- se uma representação mais real do comportamento destas estruturas. A modelagem da alvenaria consiste na representação do comportamento dos tijolos e da argamassa, assim como da interação entre eles. Elementos de interface apresentam- se como uma escolha natural para a descontinuidade física, intrínseca ao problema. Adicionalmente, eles podem representar fissuras provenientes tanto do modo I quanto do modo II, as quais representam aberturas potenciais e deslizamentos no plano, respectivamente. Para isso é necessário acoplá-los a modelos constitutivos que detectem os diversos modos de ruptura do sistema. Também são necessárias avançadas estratégias de solução que permitam seguir a formação de deformações localizadas. Como estratégias empregadas pode-se citar o controle de deslocamentos direto, controle de deslocamento relativo e controle de comprimento de arco. Neste trabalho, um modelo elasto-plástico baseado no critério de escoamento de Mohr-Coulomb foi escolhido para a representação da interface de argamassa. Exemplos foram analisados comparativamente com resultados numéricos e experimentais. / [en] Since masonry is a widely employed material, it is fundamental to better characterize its structural performance and extend its use beyond functional applications (separation of environments). In this work a finite element model for masonry structures is presented. By using a sophisticated numerical tool based on the finite element method, associated to suitable constitutive models, the behavior of these structures is represented in a more realistic way. Masonry modeling consists in representing the behavior of bricks and mortar, as well as the interaction between them. Interface elements present themselves as a natural choice for representation of the intrinsic physical discontinuities of the problem. Additionally, they can represent cracks arising from either mode I or mode II fracture, which represent potential opening and sliding planes, respectively. This requires the coupling of interface elements with constitutive models which embrace several system failure modes. In this work, an elasto-plastic model based on the Mohr- Coulomb yield criteria was chosen for the representation of the mortar interface. The brittle response of these structures often leads to localized failure modes. Advanced strategies of solution that allow us to follow the formation of localized strains are employed, namely displacement control, relative displacement control and the arc-length method. Application of this numerical tool to some numerical examples is shown and compared to experimental results. / [es] El hormigón es un material largamente utilizado por lo que es fundamental la realización de investigaciones para caracterizar su desempeño y extender su uso a un aspecto más extructural y no apenas funcional (separación de ambientes). En este trabajo se presenta un modelo de elementos finitos para extructuras de hormigón. Utilizando un modelo numérico sofisticado con base en el Método de los Elementos Finitos, asociado a un modelo constitutivo adequado, se busca una representación más real del comportamiento de estas extructuras. El modelo representa el comportamiento de los ladrillos y de la argamasa, así como de la interacción entre ellos. Elementos de la interface se presentan como una selección natural para la discontinuidad física, intrínseca al problema. Adicionalmente, se pueden representar fisuras provenientes tanto del modo ? como del modo ??, las cuales representan aberturas potenciales y deslizamentos en el plano, respectivamente. Para ello es necesario acoplarlos a modelos constitutivos que detectan los diversos modos de ruptura del sistema. Tembién son necesarias estrategias de solución avanzadas que permitan seguir la formación de deformaciones localizadas. Como estrategias empleadas se pueden citar: el control de deslocamentos, control de deslocamento relativo y control del largo del arco. En este trabajo se eligió un modelo elasto-plástico basado en el criterio de Mohr-Coulomb para la representación de la interface de argamasa. A modo de comparación se analizaron varios ejemplos con resultados numéricos y experimentales.

The traditional construction practice used in masonry buildings throughout the world is limited to walls with rectangular cross sections that, when reinforced with steel bars, typically accommodate only single-leg horizontal ties and a single layer of vertical reinforcement. This arrangement provides no confinement at the wall toes, and it may lead to instability in critical wall zones and significant structural damage during seismic events. Conversely, the development of a new building system, constructed with reinforced masonry (RM) walls with boundary elements, allows closed ties to be used as confinement reinforcement, thus minimizing such instability and its negative consequences. Relative to traditional walls, walls with boundary elements have enhanced performance because they enable the compression reinforcement to remain effective up to much larger displacement demands, resulting in a damage tolerant system and eventually, more resilient buildings under extreme events. Research on the system-level (complete building) performance of RM walls with boundary elements is, at the time of publication of this dissertation, nonexistent in open literature. What little research has been published on this innovative building system has focused only on investigating the component-level performance of RM walls with boundary elements under lateral loads. To address this knowledge gap, the dissertation presents a comprehensive research program that covered: component-level performance simulation; system-level (complete building) experimental testing; seismic risk assessment tools; and simplified analytical models to facilitate adoption of the developed new building system. In addition, and in order to effectively mobilize the knowledge generated through the research program to stakeholders, the work has been directly related to building codes in Canada and the USA (NBCC and ASCE-7) as well as other standards including FEMA P695 (FEMA 2009) (Chapter 2), TMS 402 and CSA S304 (Chapter 3), FEMA P58 (FEMA 2012) (Chapter 4), and ASCE-41 (Chapter 5). Chapter 1 of the dissertation highlights its objectives, focus, scope and general organization. The simulation in Chapter 2 is focused on evaluating the component-level overstrength, period-based ductility, and seismic collapse margin ratios under the maximum considered earthquakes. Whereas previous studies have shown that traditional RM walls might not meet the collapse risk criteria established by FEMA P695, the analysis presented in this chapter clearly shows that RM shear walls with boundary elements not only meet the collapse risk criteria, but also exceed it with a significant margin. Following the component-level simulation presented in Chapter 2, Chapter 3 focused on presenting the results of a complete two-story asymmetrical RM shear wall building with boundary elements, experimentally tested under simulated seismic loading. This effort was aimed at demonstrating the discrepancies between the way engineers design buildings (as individual components) and the way these buildings actually behave as an integrated system, comprised of these components. In addition, to evaluate the enhanced resilience of the new building system, the tested building was designed to have the same lateral resistance as previously tested building with traditional RM shear walls, thus facilitating direct comparison. The experimental results yielded two valuable findings: 1) it clearly demonstrated the overall performance enhancements of the new building system in addition to its reduced reinforcement cost; and 2) it highlighted the drawbacks of the building acting as a system compared to a simple summation of its individual components. In this respect, although the slab diaphragm-wall coupling enhanced the building lateral capacity, this enhancement also meant that other unpredictable and undesirable failure modes could become the weaker links, and therefore dominate the performance of the building system. Presentation of these findings has attracted much attention of codes and standards committees (CSA S304 and TMS 402/ACI 530/ASCE 5) in Canada and the USA, as it resulted in a paradigm shift on how the next-generation of building codes (NBCC and ASCE-7) should be developed to address system-levels performance aspects. Chapter 4 introduced an innovative system-level risk assessment methodology by integrating the simulation and experimental test results of Chapters 2 and 3. In this respect, the experimentally validated simulations were used to generate new system-level fragility curves that provide a realistic assessment of the overall building risk under different levels of seismic hazard. Although, within the scope of this dissertation, the methodology has been applied only on buildings constructed with RM walls with boundary elements, the developed new methodology is expected to be adopted by stakeholders of other new and existing building systems and to be further implemented in standards based on the current FEMA P58 risk quantification approaches. Finally, and in order to translate the dissertation findings into tools that can be readily used by stakeholders to design more resilient buildings in the face of extreme events, simplified backbone and hysteretic models were developed in Chapter 5 to simulate the nonlinear response of RM shear wall buildings with different configurations. These models can be adapted to perform the nonlinear static and dynamic procedures that are specified in the ASCE-41 standards for both existing and new building systems. The research in this chapter is expected to have a major positive impact, not only in terms of providing more realistic model parameters for exiting building systems, but also through the introduction of analytical models for new more resilient building systems to be directly implemented in future editions of the ASCE-41. This dissertation presents a cohesive body of work that is expected to influence a real change in terms of how we think about, design, and construct buildings as complex systems comprised of individual components. The dissertation’s overarching hypothesis is that previous disasters have not only exposed the vulnerability of traditional building systems, but have also demonstrated the failure of the current component-by-component design approaches to produce resilient building systems and safer communities under extreme events. / Dissertation / Doctor of Philosophy (PhD)

In this masters thesis the aim was to investigate a part of Sturegallerian in Stockholm to be reconstructed. The reconstruction did implicate that openings were to be established in an already existing masonry wall. Reconstruction of an old masonry building entails certain difficulties due to the lack of knowledge regarding the building methodology of the existing structure. The purpose of the project was to analyze the effects of a desired reconstruction. A further purpose was to identify the effect with a suggested steel amplifier. In addition it was of interest to see how different modeling strategies would effect the results and discuss what modeling strategy that was most preferred for this project. For the project the specific wall structure was established in the finite element method software, named Räumlich Finite Element Method, as well as a model with the reconstructions established. A comparison of the existing structure with the reconstructed leads to a better understanding of the characteristics of the structure and the specific loads acting on the structure. Further, two different modeling strategies were assigned: one with an isotropic material model and the other as an orthotropic. The models were evaluated for the Ultimate Limit State as well as the Serviceability Limit State to verify the critical behaviours. The models were analyzed for the specific limit states: the deformations, internal forces and the axial stresses. Further, the suggested steel amplifiers were implemented in the reconstructed models to be able to analyze the effects. When the steel amplifiers were assigned to the reconstructed models, the same limit states were analyzed for the deformations and for the internal forces. The conclusion of this project was that an orthotropic material model is best suited for masonry structures. The steel amplifiers were implemented in the orthotropic material model and were further analyzed in the Finite Element software. With the steel amplifiers one could see that the deformations decreased and were still lower than the maximum deformation. One could see that the compression stresses within the masonry wall decreased with the implemented steel amplifiers. The utilization ratio for the steel amplifier was established in Colbeam. The result of stresses, deformations, utilization ratio and stresses within the structure resulted in that this type of amplifier was considered as applicable for this project. / I denna masteruppsats var syftet att undersöka en del av Sturegallerian i Stockholm som skulle rekonstrueras. Rekonstruktionen innebar att öppningar skulle tas upp i den redan befintliga murade väggen. Ombyggnation av en gammal murad byggnad medför vissa svårigheter på grund av den begränsade mängden kunskap om den befintliga konstruktionens byggnadsmetodik. Syftet med projektet var att analysera effekterna samt förmågan att etablera den önskade rekonstruktionen. Ett ytterliggare mål var att identifiera effekterna med en föreslagen stålförstärkare för strukturen. Dessutom var man intresserad av att se hur olika modelleringsstrategier skulle påverka resultaten och diskutera vilka modelleringsstrategier som var att föredra för projekt som detta. För projektet fastställdes den specifika väggstrukturen i mjukvaran för finita elementmetoden, kallad Räumlich Finita Element Method, samt en modell med de etablerade rekonstruktionerna. Genom att jämföra den befintliga strukturen med den rekonstruerade, medförde det en bättre förståelse av strukturens beteende med de specifika belastningar som verkar på strukturen. Modellerna tilldelades två olika modelleringsstrategier: den ena etablerades med en isotrop materialmodell och den andra som ortotrop. Modellerna utvärderades för brottgränstillstånd och bruksgränstillstånd för att verifiera de kritiska beteendena. För de specifika gränstillstånden analyserades deformationerna, inre krafter samt axiella spänningar. Vidare implementerades de föreslagna stålförstärkningarna i de rekonstruerade modellerna för att kunna analysera effekterna för: deformationer, interna krafterna och spänningar. Vidare så implemenderades stålförstärkningar i ombyggnationen för att analysera effekter. När stålförstärkningarna var implementerade kunde en analys av deformationerna och de interna krafterna utföras. Slutsatsen av detta projekt var att en ortotrop materialmodell var bäst lämpad för murverk. Stålförstärkarna implementerades i materialmodellen, analyserades i Finita Element programmet. Med stålförstärkningarna kunde man se en minsking i deformationerna och att de var lägre än de maximalt tillåtna deformationerna. Tryckspänningarna minskade i murverksstrukturen med hjälp av de implementerade stålförstärkningarna. Utnyttjandegraden för stålförstärkningarna fastställdes i Colbeam. Resultaten av deformationerna, utnyttjandegraden samt spänningarna i strukturen resulterade i att denna typ av stålförstärkning bedömdes vara lämplig för detta projekt.

The aim of this Master Thesis is to assess the load carrying capacity of the Glomman Bridge outside of the Swedish city Örebro. The Glomman Bridge is an unreinforced concrete single span arch bridge with backfill. The bridge was constructed in 1923 on assignment from the Swedish National Railways (SJ). The failure criteria used in this thesis is that the bridge collapses when any cross section in the concrete arch reaches its ultimate capacity. In reality, the bridge may manage heavier loads than this. When the capacity is reached in a cross section, a hinge is formed and the arch relocates the forces to other parts of the arch that can carry higher stresses. The real bridge will not collapse until a fourth hinge is formed, and by that a mechanism. To be able to calculate the cross section forces in the arch, it was necessary to know the influences of the loads on the arch when they were run along the bridge. For this purpose, influence lines were obtained from a 2D finite element model created in ABAQUS, a general FE-analyses software. A calculation routine to find the least favourable load combination was then created in Matlab, a numerical calculation software. The routine was made to find the worst case among different load cases and to combine the standardized axle pressures with the present number of axles. A parametric survey was also performed because the material properties for the different parts of the bridge are very uncertain. In the survey, the initial values were changed one at a time to study the outcome on the load factor. The load factor is the ratio between the ultimate limit load and the actual load. The studied parameters are the compressive strength, the Young's modulus, the density and the Poisson's ratio of the different parts of the bridge. The parameters are studied individually irrespective of possible correlation. The studied parts of the bridge are the backfill, the arch, the abutments and the asphalt. The clearly most important component is found to be the backfill. With increased stiffness or increased Poisson's ratio in the backfill follows increased load factor. The equations behind the failure envelope can be derived from equilibrium equations for the unreinforced cross section. The influence lines are normalised with respect to the capacity of the cross section to get the degree of efficiency along the whole length of the arch, instead of the common influence lines that give the cross section forces. This is done because the failure is not caused by large cross section forces but by an exceeded ultimate stress. As the different loads are run along the bridge, the largest positive and negative efficiency for bending moment and normal force are localised. The normalised cross section forces are plotted together with the failure envelope and the load factor is then calculated. Several masonry arch bridges were loaded until collapse in a study performed by the British Transport and Road Research Laboratory. One of the bridges in the study, the Prestwood Bridge, has been used in this thesis as a comparison to the Glomman Bridge. The load carrying capacity of the Prestwood Bridge is known, and is used to verify that the method using the failure envelope is applicable. To compare the results from the cross section analysis from the failure envelope model to another method, the Glomman Bridge and the Prestwood Bridge were also tested in the commercial software RING 2.0. The method used in RING 2.0 differs from the failure mode in this thesis by calculating the load factor when four different cross sections reach their capacity and the bridge collapses. The failure envelope method allows an A/B-value (Axle- and Bogie load) of 102 kN/147 kN when using very poor values of the parameters and 181 kN/226 kN when using a reference case with normal parameters. Although the load capacity is found to be acceptable, the uncertainties are still large. To get a more accurate apprehension of the condition of the actual bridge, further research should be carried out, such as e.g. a non-linear model. / Syftet med föreliggande examensarbete är att uppskatta bärförmågan hos bron Glomman utanför Örebro. Glomman är en oarmerad betongvalvbro i ett spann med ovanliggande jordfyllning. Bron byggdes 1926 på uppdrag av Statens Järnvägar (SJ). Brottkriteriet i detta examensarbete är att bron går till brott när något tvärsnitt i betongbågen uppnår sin kapacitet. I själva verket är det möjligt att bron kan klara tyngre last än detta. När kapaciteten nås i ett tvärsnitt uppstår en led och bågen omlagrar krafterna till andra bågdelar som klarar större spänningar. Den verkliga bron rasar inte förrän en fjärde led har utvecklats, och därmed en mekanism. För att kunna beräkna tvärsnittskrafterna i bågen, var det nödvändigt att känna till trafiklasternas påverkan på bågen när de kördes över bron. För detta ändamål erhölls influenslinjer från en tvådimensionell finita elementmodell skapad i ABAQUS, ett generellt FE-program. En beräkningsrutin för att finna värsta tänkbara lastkombinering skapades i Matlab, ett numeriskt beräkningsprogram. Rutinen utformades för att hitta värsta fallet bland olika lastfall samt för att kombinera standardiserade axeltryck med det aktuella antalet axlar. En parameterstudie utfördes också då materialegenskaperna för de olika delarna i bron är mycket osäkra. I parameterstudien ändrades ingångsvärdena ett åt gången för att studera utslaget på lastfaktorn. Lastfaktorn är förhållandet mellan brottgränslasten och den verkliga lasten. De parametrar som studeras är tryckhållfastheten, E-modulen, densiteten och tvärkontraktionen för de olika brodelarna. Parametrarna studeras enskilt utan hänsyn till eventuell korrelation. De brodelar som studeras är fyllningen, bågen, fundamenten och asfalten. Den klart viktigaste komponenten visar sig vara fyllningen. Med ökad styvhet eller ökad tvärkontraktion i fyllningen följer ökad last­faktor. Ekvationerna bakom brottenveloppet kan härledas ur jämviktsekvationer för det oarmerade tvärsnittet. Influenslinjerna normeras med avseende på tvärsnittets kapa­citet för att få ut utnyttjandegraden längs hela bågen. Detta görs då det egentligen inte är för stor tvärsnittskraft som orsakar brott utan för stor spänning. Högsta och lägsta utnyttjandegrad för böjande moment och normalkraft lokaliseras när de olika typlasterna körs över bron. Utnyttjandegraderna placeras i brottenveloppet för att sedan räkna fram en lastfaktor. Ett flertal liknande broar har lastats till brott i en studie genomförd av British Transport and Road Research Laboratory. En av broarna i studien, Prestwood Bridge, har använts i denna rapport som jämförelse med Glomman. Då bärförmågan hos Prestwood Bridge är känd används den till att bekräfta att metoden med brott­enveloppet är tillämpbar. För att jämföra resultaten från tvärsnittsanalysen i brottenveloppmetoden med en annan metod, testades även Glomman och Prestwood Bridge i det kommersiella programmet RING 2.0. Metoden som används i RING 2.0 skiljer sig från brottmoden i denna rapport genom att istället beräkna lastfaktorn när fyra olika tvärsnitt har uppnått sina kapaciteter och bron kollapsar. Metoden med brottenvelopp tillåter ett A/B-värde (Axel- och Boggitryck) på 102 kN/147 kN när mycket dåliga parametervärden används och 181 kN/226 kN när referensfallet med normala parametervärden används. Även om bärförmågan kan anses vara acceptabel är osäkerheterna stora. För att få en nogrannare uppfattning om brons faktiska tillstånd bör fortsatta studier utföras, som t.ex. en icke-linjär modell.

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Hoy en día existen diversas estructuras en la que se ha dado la aplicación del concreto liviano estructural, por lo que empresas contratistas apuestan por agregados livianos para fabricar concreto liviano de alta resistencia y que cumpla con sus requisitos de diseño. Estos estudios comenzaron a principios de la década de 1980, con óptimos resultados en 1992. Como resultado de todos estos aportes, la información de diseño se ha convertido al alcance de muchos profesionales, y ha permitido que el concreto liviano sea utilizado en alta resistencia y alta durabilidad (Hoff 1992). Es por ello mismo, que nuestra investigación propone el uso de un concreto liviano estructural con perlita de poliestireno expandido en un sistema de albañilería confinada. Este estudio comprende la elaboración del diseño de un concreto liviano estructural; en primer lugar, se investigó un rango apropiado de perlita ya que según Thanon y Jihad (2016) señalan que para obtener óptimos resultados en resistencia a compresión la dosificación de perlita debe variar entre un intervalo de 13-23% ,y es por ello mismo que se escoge trabajar con un porcentaje de 16 % de perlita de poliestireno expandido, pero para términos de comprobación en las propiedades térmicas, también se diseñó con 26% y 36% de perlita; en segundo lugar, para proceder a realizar el diseño del concreto se diseña en base a los requisitos mínimos que establece ACI 318 y con referencias en ACI 211R, la cual interviene en ciertos parámetros para obtener las características de un concreto liviano estructural. / Today there are various structures in which there has been the application of lightweight structural concrete, so contractor companies are committed to lightweight aggregates to manufacture lightweight, high strength concrete that meets its design requirements. These studies conducted in the early 1980s, with optimal results in 1992. As a result of all these contributions, design information has become available to many professionals, and has allowed light concrete to be used for new applications and novelties where high strength and high durability are desirable (Hoff 1992). That is why our research proposes the use of a lightweight structural concrete with expanded polystyrene bead in a confined masonry system for single-family homes. This study includes the development of the design of a lightweight structural concrete; First, a range of bead was investigated since according to Thanon and Jihad (2016) it was pointed out that to obtain optimum results in compressive strength the dosage of perlite must vary between a range of 13-23%, and that is why same that it is chosen to work with a percentage of 16% expanded polystyrene perlite, but for terms of checking the thermal properties, it is also designed with 26% and 36% perlite; secondly, to proceed with the design of the concrete, it is designed based on the minimum requirements established by ACI 318 and with references in ACI 211R, the quality of intervention in specific parameters to obtain the characteristics of a lightweight structural concrete. / Tesis

A large amount of low-rise unreinforced masonry structures (URM) can be foundin Groningen, the Netherlands. More and more induced earthquakes with shortduration have been detected in this region due to gas exploitation. Local unreinforcedmasonry (URM) buildings were initially not designed for withstanding seismicactions, so that unexpected damage may occur due to their vulnerability, raising insecurityamong residents. Existing low-rise masonry buildings in Groningen can bedivided into different categories based on their characteristics. Two types of residentialmasonry buildings that fulfil the prerequisites for performing non-linear seismicassessment are chosen to be studied in this thesis project, including the terracedhouse and the detached house.The seismic assessment of structures requires the use of both a discretization methodand a seismic assessment method. The discretization method is used to translate themechanical model into a finite element model used for the numerical analysis. Severalmethods have previously shown to be applicable for seismic assessment, but thiswork investigates the implications of using a continuum model (CM) and an equivalentframe model (EFM) approach to discretization in the general-purpose finiteelement package described in DIANA-FEA-BV (2017). The continuum model approachadopted was in a previous work by Schreppers et al. (2017) validated againstexperimental results and is as such deemed representative of the physical behaviourof the mechanical models investigated. An equivalent frame model approach to beused with DIANA is proposed in the work by Nobel (2017). The continuum modelapproach uses continuum elements with a constitutive model developed for the seismicassessment of masonry structures. This constitutive model captures both shearand flexural failure mechanisms. The equivalent frame model approach uses a combinationof numerically integrated beam elements and nodal interfaces, each witha distinct constitutive model, thus decoupling the description of the flexural andshear behaviour. This approach aims to capture the macro-behaviour at the structurallevel. The applicability of the proposed equivalent frame model approach isevaluated by how well it replicates the validated continuum model approach results.The two discretization methods described are evaluated using two types of seismicassessment methods. The first seismic assessment method used consists of first performinga quasi-static non-linear pushover analysis (NLPO) on the model. Thisresults in the pushover curve, which describes the global behaviour of the modelunder an equivalent lateral load based on the fundamental mode shape of the structure.The pushover curve is then used with the N2-method described in EN1998-1iii(2004) to assess at which peak ground acceleration (PGA) that the model reachesthe near-collapse (NC) limit state. The second seismic assessment method consistsof performing dynamic non-linear time-history analyses (NLTH). This method usesrecorded accelerograms to impose the inertial forces. The PGA for the accelerogramwhere the near-collapse limit state is reached is compared to the PGA fromthe use of the N2-method. The applicability of the pushover analysis in conjunctionwith the N2-method is evaluated by how well it replicates the PGA found from thetime-history analyses and by how well it replicates local failure mechanisms.Therefore, the main objectives of this project can be described by the following twoquestions:i. To what extent can the equivalent frame method be applicable as a properdiscretization method for pushover analyses and time-history analyses oflow-rise unreinforced masonry residential buildings in the Groningen region?ii. To what extent can the non-linear pushover method be adopted toassess the seismic behaviour of low-rise unreinforced masonry residentialbuildings in the Groningen region?The applicability of the equivalent frame model showed to vary. For describing localfailure mechanisms its applicability is poor. Further work on connecting the edgepiers to transverse walls is needed. For seismic assessment using the N2-method theapplicability of the equivalent frame model approach is sensible. The conservativedisplacement capacity counteracts the fact that it is worse at describing local unloading,which produced a larger initial equivalent stiffness of the bi-linear curvesin comparison to the continuum model. For seismic assessment using the timehistorysignals, its applicability is possible. While it could show different behaviourin terms of displacement and damping forces, it still showed a similar PGA at thenear-collapse limit state for the cases at hand.The seismic assessment of the terraced and detached houses by the N2-method issimilar to the seismic prediction by applying time-history analyses. However, thereare still some variations in the initial stiffness, force capacity and displacement capacitybetween these two assessment methods due to the assumptions and limitationsin this study. Overall, considering the pros and cons of the quasi-static pushovermethod, it is deemed applicable during the seismic assessment of the unreinforcedmasonry structures in the Groningen area.

The aim of the thesis is the solution of selected parts of the building-technological project for a building in Nymburk. The content of the diploma thesis is a technical report for a building technology project, a study of the realization of the main technological stages of the building, a technical report of the building site equipment, a design of a machine assembly, a technological regulation for the execution of masonry from concrete blocks and folded ceiling constructions, a control and test plan for the implementation of masonry from concrete blocks and execution of folded concrete ceilings, OSH plan on site. In the appendix of the thesis I elaborated drawings of construction site equipment, item budget of building, object budget according to THU, construction schedule, material resources plan and dimension of building machines.