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Preservationists and historic sites managers need to be aware of the affects of excess man-made vibrations on historic structures. The purpose of this creative project is to examine those affects and identify some methods to mitigate them. To write this project, it was necessary to search through available literature identifying past research and studies on this subject. Research was culled from various sources examining the affects of vibrations on new and historic structures and are presented here in one volume.The affects of vibrations on historic structures is not a subject that is well represented in preservation or structural engineering literature. The information currently available is scattered through various sources. Thus, there is the lack of a single reference examining the affects of vibrations on historic structures. This project is meant to be used as a reference for historic preservationists, house museum curators, and historic sites managers who seek information about vibration effects and possible solutions to their vibration problem. / Department of Architecture

This treatise is a study of the methodology and the thought processes followed when buildings are designed, in order to determine to what extent, if any, designers consider the need for buildings to be maintained long after they walk off site and part with the project. The concept of taking future maintenance requirements into account as part of the design process is referred to as “designing for maintenance” (DFM). It can be assumed that, from a professional perspective, designers must keep the client’s needs in mind when designing. Facilities managers face the challenge of balancing a budget with maintaining a functional building – a dream building would be a maintenance-free building. Armed with the knowledge of DFM it is hoped that future buildings will be designed in a manner that will facilitate maintenance, thereby achieving significant savings on the life cycle costing of buildings. Buys (2004) suggests that designers should adopt a more open-minded approach toward maintenance during the design stages of buildings. Maintenance, with reference to access, methods, material and funding, could benefit from this approach, with a positive effect on the life cycle costing of a building. In order of priority when starting a building project, the design process is at the top of the list. Because this process happens right at the outset of a project, it is important to address the level of maintenance awareness that goes into designing, at this stage. The research concludes that one of the methods which could have a permanent effect on designers’ awareness of DFM would be to include it in the subjects taught at schools where designers are trained. This idea was discussed with a number of lecturers in this field and they were all in favour of this approach. There is a perception that built environment practitioners and professionals such as architects and contractors in the various fields related to the built environment, often engage in their particular task as if they exist in isolation from the project as a whole and from the rest of the project team. However, it is becoming increasingly evident that all built environment aspects are interwoven and interlinked, and that all are part of a larger context. With reference to the built environment as a whole, no action or element exists in isolation from a larger web of activity. The challenge, to nurture within students an awareness of the range and interconnectedness of elements and processes that contribute to the holistic idea, rests with the educators in the design fields, because it is clear that the final impact of any project relies to a large extent on what was specified by the designers in terms of materials and construction methods. The impact of the world’s six billion inhabitants on the environment is clearly a critical issue but does little to influence the actions of most design professionals. Documented experiences should serve as valuable tools to guide designers towards making more educated decisions on building design. Built environment professionals should educate themselves about the range of issues involved in the analysis, design and production of the built environment and the interaction between these factors.

Most existing structural health monitoring (SHM) techniques are based on measured acceleration data. Such practice, however, is highly expensive to operate, mainly due to cumbersome, time-consuming and expensive installation of sensors and their data acquisition systems. As an emerging noncontact method, the vision-based displacement sensor systems have attracted significant research interests and offered a promising alternative to the conventional sensors for SHM. However, most existing vision-based sensors require physical access to the structure to install a predesigned target panel, which has a higher contrast and thus is easier to track. Besides, most studies are carried out in controlled laboratory environments. The accuracy and robustness of vision sensors in the outdoor field conditions have not been fully investigated. It is also noted that current researches are mainly focusing on the measurement performance evaluation of vision sensors, without discussing the use of the measured displacement data for SHM. This dissertation develops a high-precision vision sensor system for remote and real-time measurement of multipoint structural displacements by tracking natural targets on structural surfaces. Two sets of software packages are developed respectively based on two advanced template matching algorithms (i.e., the upsampled cross correlation and the orientation code matching) incorporated with different subpixel techniques. Comprehensive experiments, including laboratory shaking table tests and field bridge tests, are carried out to evaluate its performance. Satisfactory agreements are observed between the displacements measured by the proposed vision sensor and those measured by high-performance reference displacement sensors. Moreover, this study examines the robustness of the vision sensor against ill environmental conditions such as dim light, background image disturbance and partial template occlusion. This dissertation further explores the potentials of the vision sensor for fast and inexpensive SHM applications, by demonstrating the usefulness of the displacement data for experimental modal analysis, finite element (FE) model updating, damage detection, etc. For a three-story frame structure, the modal analysis shows that the obtained natural frequencies and mode shapes from displacement measurements by using one camera match well with those by using four accelerometers. In fact, the vision sensor can achieve smoother mode shapes which would make damage localization more accurate, while the resolution of mode shapes from accelerometers is limited by the sensor number. This has been demonstrated from the damage detection result of beam structures based on the mode shape curvature (MSC) index. To address the needs for monitoring aging railway and highway bridges, coupled train-track-bridge and vehicle-bridge FE models are firstly developed to study the dynamic interactions between bridges and moving trains/vehicles. Subsequently, a time-domain model updating approach for railway bridges is proposed based on the in-situ measurement of the bridges’ dynamic displacement histories by the proposed vision sensor. This dissertation further proposes a bridge damage detection procedure that utilizes vehicle-induced displacement response and the MSC index without requiring prior knowledge about the traffic excitation.

In recent years there has been a significant increase in the production of concretes for agricultural buildings, especially in the area of exposure to higly chemically aggressive environments. The aim of the thesis is to describe and summarize the existing knowledge about the durability of concrete exposed to the effects of highly chemically agressive environment. Furthermore, emphasis is placed on the description of individual additives and admixtures increasing the resistance of concrete to the effect of harmful substances. In the experimental part, the effects of individual types of additives, admixtures and sealing coatings on increasing the resistance of concrete against the effect of highly chemically aggresive environment are investigated in the laboratory.

Com o crescente número de ocorrências patológicas encontradas nas estruturas de concreto armado, conforme levantamento de danos realizado por Dal Molin, 1988; Andrade, 1997, cresce também a demanda por serviços de inspeção e manutenção nos condomínios residenciais no Estado de Pernambuco e em todo o País. Entretanto, é possível observar que a prática de inspeções periódicas ainda não faz parte da cultura de uma determinada faixa da população, que não possui meios econômicos, e conhecimento da importância da manutenção para garantir a integridade da estrutura. Estas inspeções visam detectar danos à estrutura em tempo hábil a minorar os custos de reparo, aplicando assim uma manutenção preventiva como forma de garantir a vida útil estimada em projeto para a edificação. Foi utilizado neste trabalho um roteiro de inspeção com utilização de ensaios e metodologia de quantificação de danos, para verificar o estado de degradação de três edifícios residenciais, com mais de vinte anos de construídos e próximos à orla marítima onde a agressividade ambiental é forte. A deterioração encontrada em cada um dos edifícios foi devido à intervenção inadequada realizada em cada prédio. A última intervenção realizada na Edificação A, foi corretiva executada por mão de obra não qualificada orientada pelo próprio condomínio, que não tem conhecimento técnico na área de engenharia civil. Na edificação B, a situação é semelhante, agravada pela opinião de alguns condôminos de que não há necessidade desta rotina, mesmo a estrutura estando em estado crítico, conforme confirmado com a aplicação da metodologia ora proposta. E para a edificação C, na ocasião da pesquisa, existia uma empresa de engenharia civil executando os serviços de manutenção, porém isto se deve, de forma pontual, a gestão atual do condomínio / With the growing number of serious problems found in the reinforced concrete structures, according to the research on damage done by Dal Molin in 1998 and Andrade 1997, there has been a growing demand for inspections and the maintenance of residential buildings both in Pernambuco and country as a whole. However, it is possible to observe that the practice of periodical inspections is still not part of the culture of a specific section of the population, who don`t have the financial means nor a knowledge of the importance of maintenance as a guarantor of the building`s safety. These inspections aim to detect structural faults in time to minimize repair costs. Preventative maintenance is meant to guarantee the useful life of the building. In this study, there was an inspection schedule using tests and a methodology to measure damage, to check the state of direpair of three residential buildings, all more than 20 years old, all on the coast where the environmental effects are strong. The deterioration found in each of these buildings was due to inadequate preventative measures. The last action taken in Building A was undertaken by unqualified labourers directed by the condominium with no technical knowledge in the area of the civil engineering. In Building B, the situation is similar, worsened by the opinion of several residents who think that there in no need for this kind of inspection. And this even though the building is in a critical state according to the research done. As for Building C, at the time of our research, there was a civil engineering firm performing maintenance services, though this is due to last minute action taken by the present management of the building

Made available in DSpace on 2017-06-01T17:57:27Z (GMT). No. of bitstreams: 1 dissertacao_jackeline_oliveira.pdf: 2083137 bytes, checksum: f23beabe95011a655bdc05799530289f (MD5) Previous issue date: 2008-03-27 / With the growing number of serious problems found in the reinforced concrete structures, according to the research on damage done by Dal Molin in 1998 and Andrade 1997, there has been a growing demand for inspections and the maintenance of residential buildings both in Pernambuco and country as a whole. However, it is possible to observe that the practice of periodical inspections is still not part of the culture of a specific section of the population, who don`t have the financial means nor a knowledge of the importance of maintenance as a guarantor of the building`s safety. These inspections aim to detect structural faults in time to minimize repair costs. Preventative maintenance is meant to guarantee the useful life of the building. In this study, there was an inspection schedule using tests and a methodology to measure damage, to check the state of direpair of three residential buildings, all more than 20 years old, all on the coast where the environmental effects are strong. The deterioration found in each of these buildings was due to inadequate preventative measures. The last action taken in Building A was undertaken by unqualified labourers directed by the condominium with no technical knowledge in the area of the civil engineering. In Building B, the situation is similar, worsened by the opinion of several residents who think that there in no need for this kind of inspection. And this even though the building is in a critical state according to the research done. As for Building C, at the time of our research, there was a civil engineering firm performing maintenance services, though this is due to last minute action taken by the present management of the building / Com o crescente número de ocorrências patológicas encontradas nas estruturas de concreto armado, conforme levantamento de danos realizado por Dal Molin, 1988; Andrade, 1997, cresce também a demanda por serviços de inspeção e manutenção nos condomínios residenciais no Estado de Pernambuco e em todo o País. Entretanto, é possível observar que a prática de inspeções periódicas ainda não faz parte da cultura de uma determinada faixa da população, que não possui meios econômicos, e conhecimento da importância da manutenção para garantir a integridade da estrutura. Estas inspeções visam detectar danos à estrutura em tempo hábil a minorar os custos de reparo, aplicando assim uma manutenção preventiva como forma de garantir a vida útil estimada em projeto para a edificação. Foi utilizado neste trabalho um roteiro de inspeção com utilização de ensaios e metodologia de quantificação de danos, para verificar o estado de degradação de três edifícios residenciais, com mais de vinte anos de construídos e próximos à orla marítima onde a agressividade ambiental é forte. A deterioração encontrada em cada um dos edifícios foi devido à intervenção inadequada realizada em cada prédio. A última intervenção realizada na Edificação A, foi corretiva executada por mão de obra não qualificada orientada pelo próprio condomínio, que não tem conhecimento técnico na área de engenharia civil. Na edificação B, a situação é semelhante, agravada pela opinião de alguns condôminos de que não há necessidade desta rotina, mesmo a estrutura estando em estado crítico, conforme confirmado com a aplicação da metodologia ora proposta. E para a edificação C, na ocasião da pesquisa, existia uma empresa de engenharia civil executando os serviços de manutenção, porém isto se deve, de forma pontual, a gestão atual do condomínio