In this study, the load bearing behavior of piled raft foundations is investigated performing laboratory and field tests. Piled raft foundation of a multi storey building was also instrumented and monitored in order to study the load sharing mechanism of piled raft foundations. A small reinforced concrete piled raft of 2.3 m square supported by four mini piles at the corners was loaded and contribution of the raft support up to 41 % of the total load was observed. The soil was stiff fissured Ankara clay with no ground water. A building founded on a piled raft foundation was instrumented and monitored using earth pressure cells beneath the raft during its construction period. The foundation soil was a deep graywacke highly weathered at the upper 10 m with no ground water. The proportion of load that was carried by the raft was 21 to 24 % of the total load near the edge and 44 to 56 % under the core. In the laboratory tests, model aluminum piles with outerinner diameters of 2218 mm and a length of 200 mm were used. The raft was made of steel plate with plan dimensions of 176 mm x 176 mm and a thickness of 10 mm. The model piles were instrumented with strain gages to monitor pile loads. Model piled raft configurations with different number of piles were tested. The behavior of a single pile and the plain raft were also investigated. The soil in the model tests was half and half sand &ndash / kaolinite mixture. It has been observed that when a piled raft is loaded gradually, piles take more load initially and after they reach their full capacity additional loads are carried by raft. The proportion of load that was carried by the raft decreases with the increasing number of piles and the load per pile is decreased. Center, edge and corner piles are not loaded equally under rafts. It has been found that rafts share foundation loads at such levels that should not be ignored.

No description available.

In this study, the settlement behavior of the piled raft foundations resting on overconsolidated clays under uniform loading, is investigated for different pile configurations and load levels. A total of 100 plane &ndash / strain and three &ndash / dimensional finite element analyses are carried out and the results of these analyses are compared both with each other and with the results presented by Reul &amp / Randolph (2004). The material parameters used in the analysis are selected mainly referring to the previous studies cited above on the same subject and slight modifications are made for convenience in the analysis. The analysis method and the applied pile configurations and load levels are directly taken from the reference study, excluding the soil model employed. A drained Mohr &ndash / Coulomb failure criteria is employed in the analysis of this study in modeling the soil instead of an elastoplastic model which was used in the analysis of the reference study. The results are evaluated for the average and differential settlements of the foundations and it is seen that / although the average and differential settlements calculated in this study are not always very close to the values calculated in the reference study, the calculated settlement reduction factors due to piles (especially for the average settlements) compared well with the findings of the reference study for all pile configurations and load levels considered. Based on this, a new approach is suggested to estimate the average settlements of the piled raft foundations. Moreover, correction factors are recommended in order to estimate the average settlements of the piled rafts by directly using the programs employed throughout the thesis.

Two different concepts and design procedures namely settlement reducing piles and piled raft foundations have been studied independently in this thesis. A laboratory study is conducted on model rafts with differing number of model settlement reducing piles. Pile length, pile diameter, type of soil and size of raft are kept constant and settlements are measured under sustained loading. Remolded kaolin is consolidated under controlled stresses before tests are performed in model boxes. The tests are conducted under two sustained loadings of 75 kPa and 40 kPa. 0(raft), 16 and 49 number of piles are used. During the tests, all of the skin friction is mobilized. Several tests are conducted for each combination to see the variability. It is concluded that increasing the pile number beyond an optimum value is inefficient as far as the amount of settlement is considered. Also an analytical procedure has been followed to calculate settlements with increasing number of piles. In the second part of this thesis, finite element analyse have been performed on a piled raft foundation model, using Plaxis 3D Foundation Engineering software. This analyse are supported with analytical methods. The piled raft model is loaded with 450 kPa raft pressure. The studies are conducted in two sets in which different pile lengths are used / 25 m and 30 m respectively. The numbers of piles are increased from 63 to 143. All other parameters are kept constant. The results showed that again an optimum number of piles will be sufficient to reduce the settlement to the acceptable level. The analytical methods indicate a similar behavior. The comparison and results are presented in the study.

Made available in DSpace on 2014-07-29T15:18:18Z (GMT). No. of bitstreams: 1 Dissertacao de Mestrado Ruiter da S Souza 2010.pdf: 3795319 bytes, checksum: ce03329bc9c991e1ebf4ddcb63aeada9 (MD5) Previous issue date: 2010-08-06 / Researches done in the last decades concerning the settlement of pile foundations, mainly when it s considered as piled raft, had greatly evolved due the progress on computational tools used in the analysis. However, the tridimensional analysis of a pile foundation, taking into account the interaction between your components (soil, piles and raft), is still a very complex problem. To achieve a satisfactory evaluation of the interaction between the foundation's elements, numerical tools like Boundary Elements Method (B.E.M.), Finite Elements Method (F.E.M.) and hybrid methods, that combines two or more methods, are available, each one with its own advantages and drawbacks. The F.E.M. is considered in the technical sphere as the most complete method for piled raft evaluation, but your high processing time requirements, required in the analyses, prevents your usual employment. For this reason, a necessity to compare this methodology with others, as the one used in simplified programs, that decreases the processing time, arises. To evaluate the results proximity achieved by different methods, this work presents the simulation of some pile blocks, calculated as piled rafts, employing two programs (GARP and DIANA) to foresee your behavior. GARP is a hybrid program which analyzes the raft by using F.E.M. and the pilessoil set by B.E.M. and, like the other programs of same kind published in the literature, it doesn't take the influence between intermediary piles into account for the analysis. DIANA is a purely finite elements program, based on the displacement method. Thus, the main objective of this work was to evaluate how taking or not the interaction factor between piles into consideration can modify the predictions of settlement and pile loads. For that, it was evaluated how the attribution or omission of these interaction factors into specific regions that comprise some or all the piles, modifies the predictions of the foundation performance and makes them approximate or distant from the F.E.M. results, considering the most exact one. The way that the simplified programs handle the problem, makes the settlement previsions excessive. To contour this and to make the settlement results from the simplified methods become close of the expected ones from F.E.M., the discovered way was the imposition of a limit in the distance used in the calculation of the piles interaction, based on the raft's size and the number of piles in that case. Many examples of pile rafts in homogeneous soils was evaluated and the maximum distance limits of interaction between piles that generated the best results in the settlement prevision are shown. In all examples, the effect of raft stiffness in these results was also taken into account. Also, an analysis case in heterogeneous soil was done, where it was observed that this fact also interferes in the piles interaction process. For pile load predictions, the results were distinct from settlement prediction and was noticed that not limiting the maximum interaction distance between the piles generated the best previsions. / As pesquisas realizadas nas últimas décadas sobre o recalque de fundações estaqueadas, principalmente quando a mesma é considerada como radier estaqueado, tiveram grande evolução devido ao avanço das ferramentas computacionais utilizadas nas análises. Porém, a análise tridimensional de uma fundação estaqueada considerando a interação entre seus componentes (solo, estacas e radier), continua sendo um problema muito complexo. Para uma avaliação satisfatória da interação entre os elementos da fundação, ferramentas numéricas como o Método de Elementos de Contorno (M.E.C.), o Método de Elementos Finitos (M.E.F.) e métodos híbridos, que combinam dois ou mais métodos, estão disponíveis, cada uma com suas vantagens e desvantagens. O M.E.F. é considerado pelo meio técnico como o método mais completo para avaliação de um radier estaqueado, mas seu alto tempo de processamento, tomado em grande parte das análises, impede que seu uso se torne mais corriqueiro. Com isso, surge a necessidade de se comparar essa metodologia com outras, como a usada em programas simplificados, que diminuem o tempo de processamento. Para a avaliação da proximidade dos resultados determinados por diferentes métodos, esta dissertação apresenta a simulação de alguns blocos de estacas, calculados como radiers estaqueados, utilizando dois programas para prever seus comportamentos, o GARP e o DIANA. O GARP é um programa híbrido que analisa o radier pelo M.E.F. e o conjunto estacas-solo pelo M.E.C. e, como os demais programas do gênero divulgados na literatura, não considera a influência de estacas intermediárias na análise. O DIANA é um programa de elementos finitos puro, baseado no método dos deslocamentos. Assim, o principal objetivo deste trabalho foi avaliar como a consideração ou não dos fatores de interação entre estacas pode modificar a previsão de recalques e carga nas estacas. Para isso, foi avaliado como a atribuição ou a omissão dos fatores de interação dentro de regiões específicas, que englobam algumas ou todas as estacas, modificam a previsão do desempenho da fundação e fazem com que se aproximem ou se distanciem dos resultados do M.E.F., considerado o mais exato. A forma como os programas simplificados tratam o problema faz com que suas previsões de recalques sejam excessivas. Para contornar este fato e fazer com que os resultados de recalques dos métodos simplificados sejam mais próximos dos previstos pelo M.E.F., a forma encontrada foi a imposição de um limite na distância usada no cálculo da interação entre as estacas, dependendo do tamanho do radier e número de estacas do caso. Vários exemplos de radiers estaqueados em solos homogêneos foram estudados e são apresentados os limites máximos da distância de interação entre estacas que originaram melhores resultados na previsão do recalque. Em todos os exemplos avaliou-se o efeito da rigidez do radier nestes resultados. Também foi analisado um caso em solo heterogêneo, onde se observou que este fato também interfere no processo de interação entre estacas. Para a previsão de carga nas estacas o resultado foi distinto da previsão de recalques e observou-se que a não limitação da distância máxima de interação entre estacas foi o que resultou em melhores previsões.

Wind farm construction is increasing progressively, to cope-up with the current global energy scenario. The advantage of clean energy and sustainability helps wind turbine construction to flourish rapidly. Location of wind turbines is independent of foundation soil condition but depends on the wind speeds and socio-environment issues. Hence, a construction sites may not be favorable in terms of geotechnical demands. The taller wind towers facilitate the generation of high energy production, which will increase loads on the foundation, and eventually increase the dimension of the foundation. Hence, the choice of a suitable foundation system is necessary for geotechnical engineer to design tall wind towers. This study aims to analyze different foundation types e.g., raft/mat foundation, pile group foundation, and piled raft/mat foundation using analytical calculation verified with numerical models using PLAXIS 3D software. The foundation for steel wind turbine towers 100 m high was designed for different types of soils e.g., soft clayey soil, medium-stiff clayey soil, stiff clayey soil, and sandy soil. The design wind speed was taken from the ASCE 7-10 (2010) standard for Occupancy Category III and IV Buildings and Other Structures, as the Illinois region falls in that category. The parametric study was performed by varying the diameter of raft/mat, wind speed, number of piles, and soil types to evaluate the settlement in any type of foundation with load sharing proportion in piled raft/mat foundation. First, the raft/mat foundation design was carried out manually by changing the diameter of 15 m, 20 m, 25 m, 30 m, and 35 m, and changing load by considering different wind speed. Then the foundation was modeled using PLAXIS 3D software with a raft/mat diameter of 25 m, 30 m, and 35 m only, by considering the eccentricity and factor of safety criteria. With the increase in wind speed, the differential settlement on the raft/mat foundation was found to be increased. However, the increase in diameter of raft/mat caused the reduction in differential settlement. Soft clayey soil was found to be more sensitive than other soils used in the present study. For the same diameter of raft/mat, applied the same wind load, the differential settlement of foundation in soft clayey soil was found to be 6-10 times higher than the sandy soil.The position of piles was fixed based on the spacing criteria in the pile group foundation. The number of piles used in this study were 23, 32, and 46. Settlement was found to be varied with the number of piles in all soils used in this study. The lateral deflection for soft clayey soil decreased to half, when number of piles increased from 23 to 46. The differential settlement was found to be increased with the increase in wind speed in pile group foundation. Raft/mat foundation settlement was found to be 4 to 6 times higher than the settlement in pile group foundation in any soils, used in this study, for a given wind speed.The result of piled raft/mat foundation showed that the majority of the total load is shared by the piles (i.e., 60% to 94%) and remaining load is shared by the raft/mat (i.e., 6% to 40%), based on the stiffness of raft/mat and piles as well as pile-soil-pile interaction. The increase in wind speed in the wind turbines increased the differential settlement of piled raft/mat foundation in all soils. Similarly, the lateral deflection also increased with the increase in wind speed in pile raft/mat foundation in all soils. The PLAXIS 3D analysis revealed that the differential settlement in soft clayey soil was 1.5 to 2.0 times higher than the settlement in sandy soil.The validation of numerical modeling was carried out by the raft/mat foundation using Boussinesq’s theory and calculating settlement for single pile and group pile foundation. The current study showed that the soft clayey soil and medium-stiff clayey soil favor deep foundation, like pile group and piled raft/mat rather than shallow foundation, like raft/mat foundation. The results obtained from both analytical calculation and numerical modeling was found to be approximately matching. This study will help local construction company and geotechnical engineer to guide a proper foundation design of tall onshore wind turbine.

No description available.

Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2016-03-02T20:36:42Z No. of bitstreams: 1 Dissertação - Sofia Leão Carvalho - 2015.pdf: 4334945 bytes, checksum: 4ec90e6600b19acf8087cafcbd7f821f (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-03-03T12:10:10Z (GMT) No. of bitstreams: 1 Dissertação - Sofia Leão Carvalho - 2015.pdf: 4334945 bytes, checksum: 4ec90e6600b19acf8087cafcbd7f821f (MD5) / Made available in DSpace on 2016-03-03T12:10:10Z (GMT). No. of bitstreams: 1 Dissertação - Sofia Leão Carvalho - 2015.pdf: 4334945 bytes, checksum: 4ec90e6600b19acf8087cafcbd7f821f (MD5) Previous issue date: 2015-09-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The combination of two different types of foundation has become increasingly popular among engineers in the past few decades as a good alternative for large loads due to the trending expansion of taller skyscrapers. This new concept in foundation engineering, called piled raft, combines the raft capacity of withstanding large loads to the reduced settlement provided by a group of piles strategically placed. This new concept of foundation design has stimulated the use of new methodologies that look for understanding the interaction between its elements (raft, piles and soil), the settlement and the distribution of load between them. Over the past decades, the development of faster and more powerful computers has allowed engineers to use numerical methods in the analysis of this type of problem assisted by new software tools. Among all possible numerical methods, the Finite Element Method (FEM) has stood up for being precise and very adaptable to many situations. Despite its extensive applicability, the FEM method has its limitations regarding the processing time and capacity of computers mainly when the third dimension of the foundation is considered. For the fore mentioned reason, hybrid tools have been developed combining FEM to other methods aiming faster analysis and better quality results. In this context, this thesis presents a new tool, called Soil-Foundation Interaction Analysis, SoFIA. The code was developed in object-oriented programming with Approximate Computer Methods. The raft in SoFIA is modelled as two-dimensional finite plate elements, and the group soil/piles ins modelled as an elastic base. Each stage of the tool development and a set of application models are described on this report based on literature review. This work aimed creating a self-sufficient tool capable of analyzing a piled raft model with all the interaction analysis. Furthermore, the program SoFIA was modelled using object-oriented programming, anticipating future expansions, such as different finite elements, non-linear response and other types of foundation. Example results showed good agreement when compared to literature regarding settlement, share of load between raft and piles and moments in x and y directions. Moreover, the axisymmetric interaction analysis between elements of piles and soil indicated similar settlement when compared to complete tridimensional analysis and Boundary Element Method. / A união de dois tipos de fundações tornou-se, nas últimas décadas, uma boa alternativa para carregamentos de fundações maiores, necessárias diante da expansão de edificações cada vez mais altas. Esse novo conceito de fundação, chamada de radier estaqueado, uniu o radier com sua boa capacidade portante às estacas que, quando posicionadas estrategicamente, são boas redutoras de recalques, abrindo um novo campo de estudos na engenharia de fundações. A união de dois tipos de fundações tão diferentes entre si estimulou o uso de novas metodologias que buscassem compreender melhor a interação entre os elementos do radier, das estacas e do solo quanto aos recalques e principalmente, distribuição de carregamento. Com a evolução das máquinas computacionais, alguns métodos numéricos passaram a ser utilizados para analisar esse tipo de fundação e novas ferramentas computacionais surgiram nos últimos anos, dentre elas destacando-se principalmente as baseadas em Método dos Elementos Finitos. Esse método, muito eficaz, tem sido cada vez mais utilizado em todos os campos da engenharia, mas ainda possui limitações principalmente relacionadas a capacidade de processamento das máquinas, quando analisada toda a fundação em suas 3 dimensões. Por esse motivo, algumas ferramentas de metodologia híbrida, utilizando mais de um tipo de método, foram implementadas afim de simplificar a análise, sem perder em qualidade de resultados. Dentro deste contexto, esta dissertação descreve a criação do programa Soil-Foundation Interaction Analysis, SoFIA, uma ferramenta híbrida criada em linguagem orientada a objetos, que analisa o radier em elementos finitos de placas de Kirchhoff e o meio solo/estaca através da superposição das interações de seus elementos dentro do próprio programa, obtidas através de elementos finitos axissimétricos. Nesse trabalho foram mostrada as etapas de construção da ferramenta, comparando resultados a trabalhos existentes na literatura e mostrando todas as aplicações da ferramenta. O objetivo principal desse trabalho foi criar uma ferramenta autossuficiente em linguagem orientada a objetos capaz de analisar o radier estaqueado integrando a análise de interação entre estacas e solo. A escolha da linguagem objetivou a expansão a ferramenta, com novos elementos, análises não lineares e outras tipos fundações. Os exemplos analisados mostraram bons resultados comparados à literatura quanto recalque, divisão do carregamento entre radier e estacas e momentos. Além disso a utilização das interações entre elementos de estacas e solo em uma análise axissimétrica é totalmente aceitável quando comparada a uma análise completa tridimensional e a uma análise em Método dos Elementos de Contorno.

Submitted by Erika Demachki (erikademachki@gmail.com) on 2015-04-24T18:19:07Z No. of bitstreams: 2 Dissertação - Mauro Alexandre Paula de Sousa - 2014.pdf: 7399985 bytes, checksum: b0bdd649a43901b5d6a2830d1ba7eed8 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2015-04-24T18:22:57Z (GMT) No. of bitstreams: 2 Dissertação - Mauro Alexandre Paula de Sousa - 2014.pdf: 7399985 bytes, checksum: b0bdd649a43901b5d6a2830d1ba7eed8 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-04-24T18:22:57Z (GMT). No. of bitstreams: 2 Dissertação - Mauro Alexandre Paula de Sousa - 2014.pdf: 7399985 bytes, checksum: b0bdd649a43901b5d6a2830d1ba7eed8 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-09-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / With the increasing development of large urban centers in the country, the buildings are presenting more audacious forms in respect to the architectural project. The buildings got taller and as a result, the loads imposed to the foundations have also become larger. Knowing this, the concept of piled raft foundations began to be usually employed in many projects. These type of foundations assume that a load portion is supported by the surface layer that is in direct contact with the raft. The piled raft may contain a large number of piles, and some of them bearing high loads and resulting in a pronounced non-linear behavior. Aiming to describe the stress-strain behavior more accurately, a form of nonlinear analysis was implemented in FENF program (Ferramenta Numérica para Análise de Fundações). It is a specific finite element program for 3D foundation analysis of piled rafts. The program was developed at UFG using the language “C” and differs from the others programs by providing a more direct way to access the efforts that the foundation elements are submitted. The dissertation aims to do a literature review of linear and non-linear behavior of foundations and make the implementation of a hyperbolic model for modeling soil behavior. After verifying some literature cases, three different piled rafts (2x2, 4x4 and 6x6) were analyzed considering linear and non-linear soil behavior. The settlement, pile load distribution and internal efforts were compared, discussing the importance of taking into account the non-linear soil behavior. / Com o crescente desenvolvimento dos grandes centros urbanos no país, as edificações passaram a apresentar formas mais arrojadas no que diz respeito à parte arquitetônica, os edifícios ficaram mais altos e como consequência disso as cargas impostas às fundações também passaram a ser maiores. Sabendo disso, o conceito de fundações mistas passou a ser empregado na realização dos projetos. Esses tipos de fundações partem do princípio de que uma parcela do carregamento é absorvida pela camada mais superficial que está em contato direto com o bloco de coroamento ou sapata. Estas fundações mistas, também conhecidas como radier estaqueado, podem conter um número elevado de estacas e algumas delas suportarem carga elevada e com comportamento não linear pronunciado. Visando descrever o comportamento tensão-deformação de maneira mais precisa, foi implementado uma forma de análise não linear no programa FENF (Ferramenta Numérica para Análise de Fundações). Trata-se de um programa de elementos finitos especifico para analise em 3D de fundações estaqueadas e não estaqueadas. O programa foi desenvolvido na UFG em linguagem C e se diferencia dos demais por fornecer de maneira mais direta os esforços nos quais os elementos de fundações estão submetidos. A dissertação tem como objetivo fazer uma revisão bibliográfica do comportamento linear e não linear de fundações e fazer a implementação de um modelo hiperbólico para a modelagem do solo. Após a verificação da literatura, três radiers diferentes (2x2, 4x4 e 6x6), eles foram analisados considerando o solo com comportamento linear e não linear. Os recalques, a distribuição de carga e os esforços internos são comparados, discute-se a importância do comportamento não linear do solo.

Submitted by Luanna Matias (lua_matias@yahoo.com.br) on 2015-03-26T11:58:08Z No. of bitstreams: 2 Dissertação - Douglas Magalhães Albuquerque Bittencourt - 2012.pdf: 7044749 bytes, checksum: fe5d3f4437aa7025f71647fb8c7850f4 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luanna Matias (lua_matias@yahoo.com.br) on 2015-03-26T12:17:24Z (GMT) No. of bitstreams: 2 Dissertação - Douglas Magalhães Albuquerque Bittencourt - 2012.pdf: 7044749 bytes, checksum: fe5d3f4437aa7025f71647fb8c7850f4 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-03-26T12:17:24Z (GMT). No. of bitstreams: 2 Dissertação - Douglas Magalhães Albuquerque Bittencourt - 2012.pdf: 7044749 bytes, checksum: fe5d3f4437aa7025f71647fb8c7850f4 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2012-06-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / A growing demand for better-prepared projects of foundations and able to attend the high degree of structural complexity of the actions has been noted in recent years. However, the current geotechnical design philosophy shows itself outdated or unable to solve these needs, due to the fact that traditional methods of calculating piled foundations often ignore the performance of the block contact with the soil and neglect the influence of the stiffness and the interaction among the elements that makeup the foundation system. To increase the quality of the design of large pile groups, with or without associated columns, there is a need for a more rigorous treatment of the problem and, in order to achieve it, one may employ the concept of piled raft which allows an integrated analysis of the entire set responsible for the performance of the foundation: the raft, the piles and the soil. This approach has a complexity inherent of its formulation; therefore, its development is generally more successful employing numerical methods. In this context, this study aimed to develop a three-dimensional numerical tool in finite elements, using the programming language "C" for the study of piled raft foundations, which was called Ferramenta Numérica para Análise de Fundações (FENF). The program was fully developed during the research period and contrasts the commercial software available at present for outputting the results that are necessary for the project, such as stresses, strains, shear and normal efforts, displacements, and bending moments in the block and the piles etc. In addition, along with the program, a search algorithm was developed which is capable of identifying the best combination of the height and length of the block and cross section of piles that result in a viable solution with the lowest cost. In order to do so, the software employs the linear elastic constitutive model for materials and represents them through finite three-dimensional isoparametric elements with eight nodes and linear interpolation functions for the displacement fields. During its development and after it was complete, the numerical tool has been successfully validated by comparing its results with those of other programs also in finite element or with analytical solutions of the Linear Theory of Elasticity. Two examples of application of FENF have been presented with Exhaustive Search Ordered, in which: one block with 16 and another with 36 piles, allowing us to evaluate the effectiveness of the program and compare its results with those predicted by the simplified manual method. It’s been noticed that the integrated treatment of the foundation system, considering it as a piled raft, allows us to obtain a more economical and safer project. / Tem-se verificado nos últimos anos uma demanda crescente por projetos de fundações mais bem elaborados e capazes de atender ao alto grau de complexidade das ações estruturais. Entretanto, a filosofia de projeto geotécnico atual se mostra defasada ou incapaz de suprir a essas necessidades, uma vez que os métodos tradicionais de cálculo de fundações estaqueadas muitas vezes desprezam o desempenho do contato do bloco com o solo e negligenciam a influência da rigidez e da interação entre os elementos que compõem o sistema de fundação. Para o aumento da qualidade da concepção de grandes grupos de estacas, com ou sem a associação de pilares, é necessário um tratamento mais rigoroso do problema utilizando, por exemplo, o conceito de radier estaqueado. Tal abordagem permite uma análise integrada de todo o conjunto responsável pelo desempenho da fundação: o radier, as estacas e o solo, mas possui uma complexidade inerente a sua formulação sendo que o seu desenvolvimento é geralmente mais bem sucedido empregando-se métodos numéricos. Nesse contexto, este trabalho visou ao desenvolvimento de uma ferramenta numérica tridimensional em elementos finitos, utilizando a linguagem de programação “C”, para o estudo de fundações em radier estaqueado, que foi denominada de Ferramenta Numérica para Análise de Fundações (FENF). O programa foi desenvolvido integralmente durante o período da pesquisa e destaca-se dos programas comerciais atuais por disponibilizar saídas de resultados necessárias ao projeto, como tensões, deformações, deslocamentos, esforços cortantes e normais e momentos fletores para o bloco e para as estacas etc. Além disso, foi desenvolvido e incorporado ao FENF um algoritmo de busca capaz de identificar a melhor combinação de altura de bloco e comprimento e seção transversal de estacas que resultem em uma solução viável tecnicamente e com o menor custo. O programa FENF emprega o modelo constitutivo elástico-linear para os materiais e os representa por meio de elementos finitos tridimensionais isoparamétricos com oito nós e funções de interpolação lineares para os campos de deslocamentos. A ferramenta numérica foi validada com êxito, a partir da comparação de seus resultados com os de outros programas, também em elementos finitos, ou com soluções analíticas da Teoria da Elasticidade Linear. Foram apresentados dois exemplos de aplicação do FENF com a Busca Exaustiva Ordenada, sendo um bloco com 16 e outro com 36 estacas, que permitiram avaliar a eficácia do programa e comparar os seus resultados com os previstos pelo método manual simplificado. Verificou-se que o tratamento integrado do sistema de fundação, considerando-o como um radier estaqueado, permite a obtenção de um projeto mais econômico e mais seguro.