Interação solo-estrutura é o objeto de estudo deste trabalho. O principal objetivo é verificar a verdadeira importância desse fenômeno na análise estrutural de edifícios usuais em concreto armado sobre fundações diretas. Inicialmente apresenta-se um estudo sobre o comportamento do solo. Logo após são descritos os processos de dimensionamento de fundações superficiais, com base na NBR 6122 (1996). Descrevem-se em seguida os elementos barra e sapata rígida, utilizados na modelagem do sistema superestrutura-subestrutura-maciço de solos. Discute-se a modificação do elemento sapata rígida, que representa fundação e solo, para a consideração de uma camada indeslocável no interior do solo. De acordo com a teoria apresentada, dois exemplos são submetidos a duas análises, com ou sem a consideração da interação sol-estrutura, para que os resultados sejam comparados. Aplicam-se separadamente as ações verticais e horizontais. A influência duma camada indeslocável no interior do solo e os efeitos da seqüência construtiva dos edifícios também são analisados. / Soil-structure interaction is the subject of this work. The foremost aim is to verify the real importance of that phenomenon on the structural analysis of usual reinforced concrete buildings on shallow foundations. At first, it is presented a study of soil behaviour. Design procedures of shallow foundations based on NBR 6122 (1996) are described afterwards. Then, the beam and rigid footing elements, used for modelling the superstructure-infrastructure-foundation soil system, are described. It is discussed the modification of the rigid footing element, which represents foundation and soil, to consider a rigid layer within soil. According to the theory above presented, two examples are subjected to two analysis, with or without the consideration of soil-structure interaction, in order to compare the results. Vertical and horizontal loads are separately applied. The influence of a rigid layer within soil and the effects of the sequence of buildings construction are also analysed.

<p>Past earthquake damage assessments have shown the seismic vulnerability of older non-ductile reinforced concrete buildings. The life safety-risk these buildings pose has motivated researchers to study, develop, and improve modeling techniques to better simulate their behavior with the aim to prioritize retrofits.</p><p><br></p> <p>This study focuses on the lap splice detailing at the base of the building in columns, shorter than those recommended by modern codes which consider seismic effects. Current modeling efforts in non-ductile reinforced concrete frame structures have considered the connection at the foundation fixed. This study models the influence of the performance of short lap splices on the simulation of response of an instrumented perimeter-frame-non-ductile building located in Van Nuys, California, and to compare results with those of previous studies of the same building.</p><p><br></p> <p>The methodology consisted of evaluating the response of a non-ductile concrete building subjected to a suite of ground motions through the comparison of three base connections: fixed, pinned, and a rotational spring modeling the short lap splice. Comparison and performance evaluation are done on the basis of drift as the main performance metric. In the building response evaluation flexure and shear forces in frame elements were also compared using the different base conditions. </p><p><br></p> <p>The models consist of two-dimensional frames in orthogonal direction, including interior and exterior frames, totaling into 4 frames. The dynamic analysis was performed using SAP2000 analysis software. The proposed rotational spring at the base was defined using the Harajli & Mabsout (2002) bond stress – slip relationship and moment – curvature sectional analysis, applied to 24d_b and 36d_b lap splices. Deformation considered flexure and slip. Adequacy of shear strength was checked prior to the analysis to verify that shear failure did not occur prior to either reaching first yield of the column reinforcement or splice capacity. </p><p><br></p> In this study, the response of the frames using the proposed rotational spring model was found to be between the fixed and pinned base conditions with regard to roof displacement and interstory drift ratio, also termed as story drift ratio. The behavior of the frames changed depending on the yielding of the longitudinal reinforcement, as depicted by the interstory drift ratio and displacement. The performance of the building frames also depended on the ground motion. The N-S and E-W direction frame computational models considered three and four earthquakes, respectively, totaling to 14 computational models per base condition. Three computational models out of the 14 with the proposed rotational spring base condition simulated recorded roof displacement results with accuracy. In the frame simulations where yielding of most of the column longitudinal bars was not calculated, the maximum interstory drift occurred in the upper stories, matching column damage observations during the event. The findings of the study showed that short lap splice increases the drift and displacement compared to the fixed base supporting its effect, i.e. the behavior of a non-ductile reinforced concrete case study building to an earthquake.

O elevado nível de conhecimento na fabricação de novos materiais e nas etapas da elaboração do projeto de estruturas não se repete quando são avaliadas as técnicas de execução de edificações. Por outro lado, a economia globalizada tornou indispensável a racionalização na construção civil e, no que refere ao item fôrmas, esta só é possível com o ação de um profissional especializado, ainda raro no mercado de trabalho da engenharia brasileira. Neste contexto, este trabalho apresenta procedimentos para se alcançar a redução no custo final da construção quando bem delineados os projetos arquitetônico e estrutural, com ênfase em aspectos construtivos. São também mostrados os benefícios da correta definição do \"Projeto de Fôrmas\", necessidade imperiosa no conjunto de elementos gráficos que constituem o projeto de um edifício. Os princípios e as técnicas para a análise e o projeto das fôrmas para estruturas de concreto são apresentadas de acordo com a nova versão da norma brasileira (Projeto de Estruturas de Madeira - 1997), fundamentada no método dos estados limites. Os ensaios experimentais realizados nas faces laterais das fôrmas dos pilares definem uma proposta de formulação para o cálculo da pressão lateral que o concreto exerce nessas faces (segundo a teoria de Mohr-Coulomb), necessário para o dimensionamento de peças integrantes das fôrmas. Por fim, são apresentadas as premissas para a elaboração projetual de um sistema de fôrmas para edifícios de múltiplos andares. / The high level of knowledge in the production of new materials and in the steps of structural design is not present on the construction techniques of multistorey buildings. On the other hand, to global economy it becomes indispensable to introduce rationalization concepts in civil construction, especially in formwork. This introduction is only possible with the action of an expert, who is still rare in Brazilian Civil Engineering. In this context, this work aims the presentation of procedures to reach a reduction on the final cost of multi-storey buildings, when architectural and structural design are well outlined, with emphasis to constructive details. Furthermore, the benefits of a proper definition of the \"Formwork Design\" are presented, due to its fundamental role in the graphical elements of a project. The principles of formwork design are presented according to new Brazilian Code (Design of Timber Structures -1997), based on limit states method. Tests on the lateral faces of column formwork originated a proposal to estimate lateral pressures applied by the concrete (according to Mohr-Coulomb Theory), which is necessary to detail formwork elements. Finally, the premises to design the formwork of a multistorey building are presented.

As ações presentes durante a construção de estruturas de edifícios em concreto armado são significantemente influenciadas pelo processo construtivo e podem ultrapassar a capacidade resistente definida no projeto estrutural. Os pavimentos recém concretados são suportados por pavimentos previamente concretados, através de um sistema de fôrmas, escoras e reescoras. Se houver fissuração prematura os pavimentos terão maiores deformações ao longo do tempo. Assim sendo, o trabalho apresenta um procedimento de análise estrutural que leva em conta a seqüência natural de construção. A definição das ações nos pavimentos durante a construção estabelece a história de carregamentos dos elementos estruturais do início ao fim da obra. Os modelos tridimensionais (utilizando o método dos elementos finitos) aqui apresentados consideram que o tempo altera as propriedades de resistência e deformabilidade do concreto antes dos 28 dias. Com isso, é definido um novo método para a determinação da distribuição das ações de construção entre o sistema de escoramento e os pavimentos interligados (Método Aproximado). Além disso, propõe-se uma nova metodologia para verificação dos estados limites considerando a existência das etapas de construção. / The loads during construction of multistory reinforced concrete structures are significantly influenced by the construction schedule and can exceed the supporting structure\'s design capacity. The fresh floors are supported by previously cast floors, through a system of forms, shores and reshores. If cracked prematurely, the floors will have larger time-dependent deflections. Then, the text presents a procedure for structural analysis that takes into account the natural sequence of construction. Definition of the loads on floors during construction provides a view of the history of structural element loads from the beginning to the end of construction work. The tridimensional models (using the finite element method) presented herein considers that the time affects the strenght and deformability properties of concrete before 28 days. Then, a new method for determining how the construction loads are distributed among the shoring system and the interconnected floors is defined (Approximated Method). Further, a new methodology for the limit states verification taking into account the construction phases is proposed.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Atualmente, os projetos de edifícios altos necessitam cada vez mais de sistemas estruturais simples, que agilizem sua montagem, reduzindo os custos e promovendo maior flexibilidade de utilização para os espaços construídos. Com essa finalidade, estruturas com poucas vigas vêm sendo muito utilizadas. Entretanto, o sistema estrutural com poucas vigas pode ocasionar dois tipos de problemas, relacionados entre si, a saber: diminuição do sistema de contraventamento da edificação e vibrações excessivas. Portanto, é fundamental, nesses casos, a verificação da estabilidade global da estrutura, utilizando índices de sensibilidade além de outros parâmetros de projeto, como também, o desenvolvimento de um estudo minucioso acerca do conforto humano da edificação. Assim sendo, neste trabalho de pesquisa foram investigados quatro modelos estruturais de edifícios altos de concreto armado, com base no estudo da variação entre o número de pavimentos e a quantidade de vigas existentes em cada modelo, objetivando-se verificar quais os efeitos que tais variações podem vir a gerar sobre a estabilidade global e, bem como, sobre o conforto humano dos sistemas estruturais investigados. A modelagem numérica dos edifícios em estudo foi realizada através do emprego do programa ANSYS e, para tal, foram utilizadas técnicas básicas de discretização, por meio do método dos elementos finitos. As conclusões alcançadas ao longo da investigação versam acerca do estudo da resposta estrutural estática e dinâmica dos edifícios, no que diz respeito as variações dos valores dos parâmetros de instabilidade, dos valores dos deslocamentos e esforços, e, bem como, dos níveis de conforto humano de cada modelo estrutural analisado. / Currently, the tall buildings projects increasingly need a simple structural systems that streamline their assembly, reducing costs and promoting greater flexibility of use for the built environment. For this purpose, structures with few beams are being widely used. However, the structural system with few beams may cause two kinds of problems, related to each other, namely: reduction of the bracing system of the building and excessive vibration. It is therefore vital in such cases, the verification of global stability of the structure, using sensitivity indexes and other design parameters, as well as the development of a thorough study of the human comfort of the building. Therefore, this research work have been investigated four structural models of tall buildings of reinforced concrete, based on the study of the variation of the number of floors and the quantity of beams in each model, aiming to verify what effects these variations. They are likely to generate on the overall stability and, as well as on human comfort and structural systems investigated. The numerical modeling of buildings under study was performed by employing the ANSYS program, and to such basic techniques of discretization were used through the finite element method. The conclusions reached during the investigation turn concerning the study of the static and dynamic structural response of buildings in respect of the variations of the values of the instability criteria, of the values of displacements and efforts, and as well, the human comfort level each structural model analyzed.

O elevado nível de conhecimento na fabricação de novos materiais e nas etapas da elaboração do projeto de estruturas não se repete quando são avaliadas as técnicas de execução de edificações. Por outro lado, a economia globalizada tornou indispensável a racionalização na construção civil e, no que refere ao item fôrmas, esta só é possível com o ação de um profissional especializado, ainda raro no mercado de trabalho da engenharia brasileira. Neste contexto, este trabalho apresenta procedimentos para se alcançar a redução no custo final da construção quando bem delineados os projetos arquitetônico e estrutural, com ênfase em aspectos construtivos. São também mostrados os benefícios da correta definição do \"Projeto de Fôrmas\", necessidade imperiosa no conjunto de elementos gráficos que constituem o projeto de um edifício. Os princípios e as técnicas para a análise e o projeto das fôrmas para estruturas de concreto são apresentadas de acordo com a nova versão da norma brasileira (Projeto de Estruturas de Madeira - 1997), fundamentada no método dos estados limites. Os ensaios experimentais realizados nas faces laterais das fôrmas dos pilares definem uma proposta de formulação para o cálculo da pressão lateral que o concreto exerce nessas faces (segundo a teoria de Mohr-Coulomb), necessário para o dimensionamento de peças integrantes das fôrmas. Por fim, são apresentadas as premissas para a elaboração projetual de um sistema de fôrmas para edifícios de múltiplos andares. / The high level of knowledge in the production of new materials and in the steps of structural design is not present on the construction techniques of multistorey buildings. On the other hand, to global economy it becomes indispensable to introduce rationalization concepts in civil construction, especially in formwork. This introduction is only possible with the action of an expert, who is still rare in Brazilian Civil Engineering. In this context, this work aims the presentation of procedures to reach a reduction on the final cost of multi-storey buildings, when architectural and structural design are well outlined, with emphasis to constructive details. Furthermore, the benefits of a proper definition of the \"Formwork Design\" are presented, due to its fundamental role in the graphical elements of a project. The principles of formwork design are presented according to new Brazilian Code (Design of Timber Structures -1997), based on limit states method. Tests on the lateral faces of column formwork originated a proposal to estimate lateral pressures applied by the concrete (according to Mohr-Coulomb Theory), which is necessary to detail formwork elements. Finally, the premises to design the formwork of a multistorey building are presented.

Studien går ut på att undersöka vattenskador som har blivit allt vanligare i svenska byggnader. Vattenskador utsätter människan för hälsorisker på grund av en hög risk för mikrobiell tillväxt. Syftet med studien är att undersöka vattenskador, var uppstår vattenskador och varför, vilka kostnader står försäkringsbolagen för och vilka kostnader står fastighetsägare eller utförare för. Inom studien undersöktes också hur olika aktörer ser på vattenskador och risker med olika typer av stommaterial. Resultatet av studien visar att försäkringsbolagen bedömer alla stommaterial lika när det gäller ersättning för vattenskador, det vill säga att de behandlar trä- och betongstomme på samma sätt. Däremot är ålder på byggnaden mer avgörande då de gör åldersavdrag för att värdera ersättningen för respektive vattenskada. Skador bör åtgärdas så fort som möjligt. Ju snabbare skador åtgärdas desto mindre sprider sig vattenskadorna. Metoden som användes i arbetet är intervjuer. / The study aims to investigate water damage that has become increasingly common in Swedish buildings. Water damage exposes humans to health risks due to a high risk for microbial growth. The purpose of the work is to discuss water damage, where water damage occurs and why, what costs do the insurance companies cover and what costs do the property owners cover. The study also examines how different actors view water damage and risks with different types of frame material. The result of the study is that the insurance companies assess all frame materials equally in terms of compensation for water damage, that is, they treat wood and concrete frames in the same way. However, the age of the building is more decisive as they make age deductions to evaluate the compensation for the respective water damage. Damage should be remedied as soon as possible, the faster the damage is rectified the less water damage spreads. The method used in the work was a qualitative method and the reliability is considered high since the results are consistent with the theoretical starting points.

Earthquakes are among natural disasters with significant damage potential / however it is possible to reduce the losses by taking several remedies. Reduction of seismic losses starts with identifying and estimating the expected damage to some accuracy. Since both the design styles and the construction defects exhibit mostly local properties all over the world, damage estimations should be performed at regional levels. Another important issue in disaster mitigation is to determine a robust measure of ground motion intensity parameters. As of now, well-built correlations between shaking intensity and instrumental ground motion parameters are not yet studied in detail for Turkish data. In the first part of this thesis, regional empirical Damage Probability Matrices (DPMs) are formed for Turkey. As the input data, the detailed damage database of the 17 August 1999 Kocaeli earthquake (Mw=7.4) is used. The damage probability matrices are derived for Sakarya, Bolu and Kocaeli, for both reinforced concrete and masonry buildings. Results are compared with previous similar studies and the differences are discussed. After validation with future data, these DPMs can be used in the calculation of earthquake insurance premiums. In the second part of this thesis, two relationships between the felt-intensity and peak ground motion parameters are generated using linear least-squares regression technique. The first one correlates Modified Mercalli Intensity (MMI) to Peak Ground Acceleration (PGA) whereas the latter one does the same for Peak Ground Velocity (PGV). Old damage reports and isoseismal maps are employed for deriving 92 data pairs of MMI, PGA and PGV used in the regression analyses. These local relationships can be used in the future for ShakeMap applications in rapid response and disaster management activities.

In this study, the seismic fragility assessment of low-rise and mid-rise reinforced concrete frame buildings which constitute approximately 75 % of the total building stock in Turkey is investigated to quantify the earthquake risk. The inventory used in this study is selected from D&uuml / zce damage database which was compiled after the devastating 1999 earthquakes in the Marmara region. These buildings are not designed according to the current code regulations and the supervision in the construction phase is not adequate. The building database is divided into sub-classes according to the height and absence of infilled walls. Each building in the database is represented by an equivalent single degree of freedom system with three structural parameters: period, strength, and post-elastic stiffness ratio. The ground motion records are selected from different parts of the world covering a wide range of characteristics. The capacity of the structure is represented for each sub-class by the limit states. Hence, a set of fragility curves for low- and mid-rise reinforced concrete structures are developed by making use of the building characteristics in the database. The generated fragility curve set is referred as &ldquo / reference&rdquo / since it forms the basis of a parametric study. A parametric study is conducted to examine the influence of post-elastic stiffness ratio, simulation and sampling techniques, sample size, limit state definition and degrading behavior on the final fragility curves. Estimated damage distribution after two consecutive major earthquakes is compared with the actual field data in order to investigate the validity of the generated fragility curves.

Environmental changes are great challenges that humanity must face. This has spurred a flurry of activities aimed to lower our impact on our environment. This essay focuses on the aspects that influence decision makers when choosing construction materials as well as a look into whether wood has a lower impact on the environment compared to concrete when building houses. The materials have been assembled through surveys, interviews and literary studies. The primary factor that was given most weight among entrepreneurs and architects were robustness and safety, and concrete was in that regard favoured over wood. It is also possible that already established economical structures support the use of concrete instead of wood. Environmental aspects are not reflected among entrepreneurs as very important factors when it comes to choosing materials and for change to occur there needs to be more information supporting that wood can be as robust as concrete in structures for it to be similarly prioritised. Concerning wood’s impact on the climate and the environment compared to concrete there is a significant difference in woods favour if only the construction and production phase of the house’s life cycle is examined. However, there are studies that show that depending on the material used and the time the house is expected to remain there are instances where wood has a higher environmental impact than concrete. Conclusively, wood is not always more environmentally friendly. The environmental impact of a material in construction depends heavily on the life span of the house.