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1	Análise dos modelos estruturais para determinação dos esforços resistentes em sapatas isoladas / Analysis of structural models to determine limit forces in spread footing Silva, Edja Laurindo da 17 August 1998 (has links) Esta dissertação de mestrado discute e analisa os critérios especificados em normas brasileiras e internacionais sobre projetos de sapatas isoladas em concreto armado, com relação a determinação dos esforços solicitantes, dimensionamento e detalhamento das armaduras. O trabalho contém as recomendações essenciais para o projeto e a construção de sapatas isoladas, como o tipo de fundação rasa mais freqüentemente utilizado. São discutidos os critérios apresentados no Boletim número 73 do CEB (1970), da norma brasileira \" Projeto e execução de obras de concreto armado\", NBR 6118 (1982), do Código Modelo do CEB - FIP (1991), Código de Projeto de Edifícios do ACI 318/1995, Eurocode 2 (1992) e do Texto Base para Revisão da NB 1/78(1992) e alguns modelos de cálculo não normalizados mas encontrados na literatura técnica. Observa-se em alguns desses códigos a omissão com relação ao dimensionamento no estado limite último de sapatas isoladas, onde foram, portanto, adaptados critérios indicados para lajes maciças. Exemplos de projetos de sapatas isoladas submetidas a ação centrada, excêntrica com plano de ação do momento paralelo a um dos lados do pilar e sapata com ação centrada e momentos paralelos aos dois lados do pilar são analisados para facilitar o entendimento dos conceitos emitidos pelas várias normas citadas e que são utilizadas comumente pelo meio técnico. Observou-se nos exemplos apresentados que para as tensões normais de tração foram encontradas armaduras mínimas ou valores próximos aos mínimos. Para os valores das forças cortantes e forças para verificar a punção, em alguns casos, se aproximaram das forças últimas. Foi notado que geralmente os efeitos das tensões cisalhantes determinam não só as alturas das sapatas mas também todo o seu dimensionamento. / This Thesis discusses and analyses the footing design criteria of Brazilian Code and also some international codes, in regarding to internal forces determination, dimensioning and reinforcement distribution. This work has essential recommendations to design and construct spread footing, such as the most frequently used types of shallow foundation. Criteria presented in the CEB/1970, NBR 6118/1982, CEB MC-90, ACI 318/1995, EC-2/92, and in the text which can be used as the basis for revised version of the Brazilian Code NB 1/78(1992) are discussed as well as some design models that are not yet normalized but it can be found at technical literature. lt can be observed in some of these Codes that since they do not take into consideration the ultimate limit state in spread footing design, some criteria that are applicable to slabs were adapted for this study. Some examples of spread footing under compression load design, spread footing under eccentric load having flexure plane in one side of column and in both side of column, are analysed to help understanding the concepts on the cited Codes. lt was noted on the examples that it was founded the minimum reinforcement when the structure was submitted to tension stress. Shear forces and forces used to verify punching shear effects reached the ultimate forces in some cases. lt was observed that shear tension effects determine the footing high as well as every footing dimensions. Concreto armado Design Dimensionamento Reinforced concrete Sapatas isoladas Spread footing
2	Análise dos modelos estruturais para determinação dos esforços resistentes em sapatas isoladas / Analysis of structural models to determine limit forces in spread footing Edja Laurindo da Silva 17 August 1998 (has links) Esta dissertação de mestrado discute e analisa os critérios especificados em normas brasileiras e internacionais sobre projetos de sapatas isoladas em concreto armado, com relação a determinação dos esforços solicitantes, dimensionamento e detalhamento das armaduras. O trabalho contém as recomendações essenciais para o projeto e a construção de sapatas isoladas, como o tipo de fundação rasa mais freqüentemente utilizado. São discutidos os critérios apresentados no Boletim número 73 do CEB (1970), da norma brasileira \" Projeto e execução de obras de concreto armado\", NBR 6118 (1982), do Código Modelo do CEB - FIP (1991), Código de Projeto de Edifícios do ACI 318/1995, Eurocode 2 (1992) e do Texto Base para Revisão da NB 1/78(1992) e alguns modelos de cálculo não normalizados mas encontrados na literatura técnica. Observa-se em alguns desses códigos a omissão com relação ao dimensionamento no estado limite último de sapatas isoladas, onde foram, portanto, adaptados critérios indicados para lajes maciças. Exemplos de projetos de sapatas isoladas submetidas a ação centrada, excêntrica com plano de ação do momento paralelo a um dos lados do pilar e sapata com ação centrada e momentos paralelos aos dois lados do pilar são analisados para facilitar o entendimento dos conceitos emitidos pelas várias normas citadas e que são utilizadas comumente pelo meio técnico. Observou-se nos exemplos apresentados que para as tensões normais de tração foram encontradas armaduras mínimas ou valores próximos aos mínimos. Para os valores das forças cortantes e forças para verificar a punção, em alguns casos, se aproximaram das forças últimas. Foi notado que geralmente os efeitos das tensões cisalhantes determinam não só as alturas das sapatas mas também todo o seu dimensionamento. / This Thesis discusses and analyses the footing design criteria of Brazilian Code and also some international codes, in regarding to internal forces determination, dimensioning and reinforcement distribution. This work has essential recommendations to design and construct spread footing, such as the most frequently used types of shallow foundation. Criteria presented in the CEB/1970, NBR 6118/1982, CEB MC-90, ACI 318/1995, EC-2/92, and in the text which can be used as the basis for revised version of the Brazilian Code NB 1/78(1992) are discussed as well as some design models that are not yet normalized but it can be found at technical literature. lt can be observed in some of these Codes that since they do not take into consideration the ultimate limit state in spread footing design, some criteria that are applicable to slabs were adapted for this study. Some examples of spread footing under compression load design, spread footing under eccentric load having flexure plane in one side of column and in both side of column, are analysed to help understanding the concepts on the cited Codes. lt was noted on the examples that it was founded the minimum reinforcement when the structure was submitted to tension stress. Shear forces and forces used to verify punching shear effects reached the ultimate forces in some cases. lt was observed that shear tension effects determine the footing high as well as every footing dimensions. Concreto armado Dimensionamento Sapatas isoladas Design Reinforced concrete Spread footing
3	Comparative Bearing Capacity Analysis of Spread Footing Foundation on Fractured Granites Nandi, Arpita 01 August 2011 (has links) It is evident from several studies that ultimate bearing capacities calculated by traditional methods are conservative and subjective. For large civil structures founded on spread footings, cost-effective and safer foundation could be achieved by adopting optimum ultimate bearing capacity values that are based on an objective and pragmatic analysis. There is a pressing need to modify the existing methods for accurate estimation of the bearing capacities of rocks for spread footings. In practice, foundation bearing capacities of rock masses are often estimated using the presumptive values from Building Officials Code Administrators, National Building Code, and methods adopted by the American Association of State Highway and Transportation Officials. However, the estimated values are often not realistic, and site-specific analyses are essential. In this study, geotechnical reports and drill-log data from successful geotechnical design projects founded on a wide range of granites in eastern Tennessee were consulted. Different published methods were used to calculate ultimate bearing capacity of rock mass. These methods included Peck, Hansen and Thornburn, Hoek and Brown, Army Corps of Engineers, Naval Facilities Engineering Command, and Terzaghi's general bearing capacity equations. Wide variation was observed in the calculated ultimate bearing capacity values, which ranged over about two orders of magnitude. Only two of the methods provided realistic results when validated with plate-load test data from similar rocks. comparative analysis GSI RMR spread footing ultimate bearing capacity Geosciences
4	Analysis of spread footing settlement for highway bridge foundation Santoso, Budi January 1991 (has links) No description available. Engineering, Civil Spread Footing Settlement Highway Bridge Foundation
5	Förstärkning av plattgrundläggning vid påbyggnad / Reinforcement of slab foundation during superstructure enlargement Koivisto, Markus, Barthélemy, Thomas January 2021 (has links) Befolkningsökningen och urbaniseringsprocessen gör att fler bostäder och andra byggnader måste uppföras i städerna. Stadsförtätning är en planeringsstrategi där påbyggnad av befintliga byggnader är en lösning. Vid påbyggnad måste nya laster bäras av en befintlig konstruktion och beroende på påbyggnadens omfattning och materialval används olika förstärkningsmetoder. Syftet med denna studie är att undersöka en förstärkningsmetod genom breddning av pelarfundament. Konsekvenserna inom två teknikområden: geoteknik och byggnads-konstruktion, har studerats. Frågeställningarna har varit likartade: vilka undersökningar måste göras och vilken bärförmåga har en konstruktion som pålastas före och efter förstärkning av pelarfundamentet? Parallellt med studier av litteratur har intervjuer med konstruktör och geotekniker utförts, för att skapa en tydlig inriktning på arbetet. Några metoder för förstärkning av pelarfundament presenteras. Förutom specialiserad litteratur, rapporter och uppsatser som utgör den största delen av teoriavsnittet i denna studie, har Eurokoderna utgjort referens, främst vid konstruktionsberäkningar men också för det avsnitt som berör geoteknik. För att kunna utföra relevanta beräkningar har ett fiktivt fall tagits fram. Utifrån bygghandlingar och uppmätningar i ett befintligt parkeringshus i Lund, har de vertikala lasterna före och efter påbyggnad beräknats. Den befintliga byggnaden var grundlagd på grov- och mellansand men placerades i det fiktiva fallet i Malmö och grundlades på lermorän. Utifrån de stipulerade förutsättningarna har en dimensionering vid förstärkning av det befintliga pelarfundamentet redovisats i form av beräkningskontroller samt ritningar. Vid dimensionering av pelarfundamentet har olika beräkningsmodeller använts. Flera avgränsningar har gjorts; exempelvis att horisontella laster inte beaktats och vertikala laster verkar centriskt, i syfte att ge en överskådlig bild av de vanligast förekommande beräkningarna och kontrollerna som måste göras vid fundamentförstärkning. I det aktuella fallet var sidan på det kvadratiska pelarfundamentet 2,8 m lång och dess tjocklek 0,6 m. De vertikala lasterna före påbyggnad uppskattades till 2242 kN och ökade till 3894 kN efter påbyggnad. Jorden blev då belastad nära maximal tillåten spänning och den befintliga betongkonstruktionen hade inte kapacitet för att bära de nya lasterna. En ökning av plattans breddmått med 0,45 m på samtliga sidor beräknades nödvändig för att behålla samma spänning i jorden. För att uppnå en godtagbar kapacitet antogs en pågjutning à 0,2 m också vara nödvändig. Även en breddning av den rektangulära pelaren antogs. Beräkningskontrollerna godkände de nya dimensionerna samt fastställde kvantiteten av nytt armeringsjärn som skulle användas, dels för att förlänga den befintliga armeringen, dels för att förbättra vidhäftningen mellan den gamla och den nya betongen. Val av förstärkningsmetod är förknippad med flera faktorer såsom läget inom byggnadskonstruktionen, geokonstruktionens skick, markförhållanden, mm. Därför är inte en metod bättre än en annan; lämplig metod måste bestämmas från fall till fall. Som studien visar skall en arbetsmetodik följas med undersökningar och relevanta beräkningar. Slutsatserna är att studiens resultat bedöms rimliga, men noggrannare dimensionering skulle kunna utföras med FEM-program. / The increase in population and the urbanization process means that more buildings must be built in the cities. Extension of existing buildings is a solution to increase housing capacity, but the existing structure must be strengthened to be able to carry the new loads. The purpose of this study is to investigate a strengthening method of spread footing in two technical fields: geotechnics and building construction. The questions were: what investigations must be made and what load-bearing capacity has a structure that is loaded before and after enlargement of the spread footing? In addition to specialized literature, reports and essays, the Eurocodes have been a reference. Some methods for enlargement of spread footing are presented. A fictitious case has been developed based on construction documents and measurements in an existing parking garage that was placed in Malmö and founded on clay till. A dimensioning for enlargement of the existing spread footing has been reported in the form of calculation checks and drawings. The vertical loads before the extension were estimated at 2242 kN and increased to 3894 kN after the extension. An increase in the width of the footing by 0.45 m on all sides was calculated necessary to maintain the same tension in the ground. In order to achieve an acceptable capacity, an overlay of 0.2 m was also assumed to be necessary. The calculation controls approved the new dimensions and determined the quantity of new dowels to be used, partly to extend the existing reinforcement, partly to improve the adhesion between the old and the new concrete. The choice of enlargement method is associated with several factors therefore, one method is not better than another. The appropriate method must be determined on a case-by-case basis with a working methodology with surveys and relevant calculations. The conclusions are that the results of the study are considered reasonable, but more accurate dimensioning could be performed with FEM-programs. spread footing superstructure adhesion strengthening pelarfundament påbyggnad vidhäftning förstärkningsåtgärder Building Technologies Husbyggnad
6	Polyfunkční dům, Brumov - Bylnice / Multifunctional building, Brumov - Bylnice Skřek, Daniel January 2020 (has links) The subject of this diploma thesis is the design of a multifunctional building, which consists of parking lots, store section, office as well as dwelling units. Multifunctional building has four above-ground floors, full basement and a flat roof. During processing, emphasis was placed on layout solutions to be designed according to legislation and standards. In the basement there are parking lots, the ground flood is used as a store section, the first floor consists of office units designed for start-up companies. The third and fourth floor consists dwelling units from one-bedroom to three-bedroom apartments. The building has a concrete frame structure combined with a masonry system from Porotherm ceramic pieces. Horizontal load bearing system is designed of two way reinforced concrete slabs. Walls bellow the ground level are made from core-filled reinforced concrete blocks. The building is supported by the spread footing concrete system. Multifunctional building is situated in flat terrain in the city of Brumov-Bylnice.
7	Effets des incertitudes et de la variabilité spatiale des propriétés des sols et des structures sur le dimensionnement des semelles filantes et des conduites enterrées / Effects of uncertainties and spatial variation of soil and structure properties on geotechnical design : cases of continuous spread footings and buried pipes Imanzadeh, Saber 15 February 2013 (has links) Le sol présente une variabilité spatiale des propriétés physiques et mécaniques dont les effets sur des structures légères avec semelles filantes et sur les conduites enterrées ne sont pas bien pris en compte dans leur dimensionnement. Cette variabilité naturelle peut être très importante dans le cas de ces ouvrages car elle induit des tassements différentiels, dont les conséquences peuvent être dommageables : fissures dans les murs, les poutres ou encore des fuites dans les réseaux d’assainissement. La variabilité naturelle du sol et l'incertitude liée à la connaissance imparfaite des propriétés du sol et/ou du béton ou de l'acier de la structure sont les principales sources d'incertitude dans le choix des paramètres de calcul pour le dimensionnement de ces structures. Dans cette thèse, une approche analytique avec les méthodes probabilistes (FOSM et SOSM) et le modèle de Winkler, puis numérique avec le couplage de la méthode des éléments finis avec des approches géostatistiques ont été successivement menées pour modéliser le comportement des semelles filantes et des conduites enterrés lorsque les incertitudes sur les propriétés mécaniques du sol et de la structure sont prises en compte dans leur dimensionnement. Il apparait ainsi, l’importance du comportement longitudinal de ces ouvrages et du poids des incertitudes dans leur dimensionnement. / Soil exhibits spatial heterogeneities resulting from the history of its deposition and aggregation processes that occur in different physical and chemical environments. This inherent or natural variability can be very important in the case of the superficial geotechnical works inducing differential settlements, whose consequences on structural response can be harmful: local failures, cracking in beams or walls, leakage in sewers. Natural variability of soil and uncertainty related to imperfect knowledge in soil properties and/or of concrete or steel of the structure, are the major source of uncertainty in the choice of the design parameters. In this thesis the probabilistic methods in geotechnical engineering, the analytical Winkler model and the coupling of the finite element method with geostatistical approaches were successively used to model the behavior of shallow foundations and buried pipe networks when soil and structure uncertainties are considered in their design. Incertitude Variabilité spatiale Module de réaction du sol Semelle filante Conduite enterrée Interaction sol-structure Approches analytique et numérique Géostatistique Uncertainty Spatial variability Subgrade reaction modulus Spread footing Buried pipe Soil-structure interaction Analytical and numerical methods Geostatistic 关键词误差空间变化土质反应模块条形地基地下管道土地-结构的相互作用分析方法与数字方法地质统计 Incertidumbre Variabilidad espacial Módulo de reacción del suelo Cimientos continuos (zapatas) Tubería enterrada (canalización) Interacción suelo – estructura Modelos analíticos y numéricos Geoestadística Incertitudine Variabilitate spațială Modul de reacție Conducta îngropată Interactiune sol-structura Modele analitice și numerice Geostatistică Belirsizlik Mekansal değişkenlik Yer reaksiyonu modülü Şerit temeller Gömülü boru Zemin-yapı etkileşimi Analitik ve sayısal yaklaşımlar Jeoistatistik Неопределенность Закопанные трубы Геостатистика Incertezza Variabilità spaziale Modulo di reazione del calore del sole Soletta conduttiva Condotta interrata Interazione delle strutture del suolo Approccio analitico e numerico Geostatico مبدأ الريبة التغير المكاني الأساسات المنفصلة الانابيب المطمورة الاحصاءات الجغرافية عدم قطعیت تغييرپذيري فضايي مدول واکنش بستر سطحي فونداسيون لوله هاي مدفون اثر متقابل سازه و خاک روشهای عددي و تحليلي

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