Loading...
Publication
Reforço de fundações de edifícios com microestacas
| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 37.42 MB | Adobe PDF |
Authors
Abstract(s)
Dentro do contexto geotécnico e estrutural da engenharia civil, as fundações configuram-se como elementos fundamentais para a estabilidade e desempenho da superestrutura. Com o passar do tempo, e frente a processos de degradação, a necessidade de reforço e reabilitação tem se tornado cada vez mais relevante, especialmente em projetos de reabilitação urbana. Nesse cenário, destaca-se o uso de microestacas, proposta por Fernando Lizzi em 1982, como uma solução de fundação profunda, de pequeno diâmetro, elevada resistência a esforços axiais e alta versatilidade, adequada a obras em ambientes restritos. A presente dissertação tem como objetivo desenvolver uma análise comparativa e paramétrica sobre o reforço de fundações com microestacas. Para isso, foram criadas duas ferramentas de cálculo em Excel, com uso de VBA, que permitem aplicar metodologias de análise estrutural e geotécnica. Os resultados dessas ferramentas foram analisados e comparados com os obtidos pelo software Geo5, com o intuito de validar as abordagens propostas. A primeira ferramenta contempla diferentes métodos de dimensionamento estrutural e geotécnico, permitindo a comparação direta entre abordagens clássicas da literatura e o software Geo5, além de possibilitar a avaliação do estudo paramétrico. A segunda ferramenta é voltada para gerar estimativas iniciais de dimensionamento estrutural e geométrico, por meio de informações de entrada, como comprimento da raiz ou diâmetro da microestaca. A dissertação está dividida em 7 capítulos principais que abordam desde a contextualização teórica do tema até o desenvolvimento prático das ferramentas de cálculo e a interpretação dos resultados. Foram realizadas 10 variações do estudo de caso, para avaliar a influência do diâmetro tubular, espessura, comprimento livre, corrosão, diâmetro de perfuração, comprimento da raiz e pressão da injeção. Os outros casos são específicos para validação da segunda ferramenta como instrumento auxiliar em análises iniciais de projeto. Os resultados evidenciam o comportamento diferente dos métodos frente às variações do estudo paramétrico. No campo estrutural, o método de Jimenez Salas (1980) demonstrou maior sensibilidade às variações geométricas da armadura tubular. Em contraste, o método geométrico de Euler (1936) apresentou menor sensibilidade. Já no campo geotécnico, alguns métodos – Zweck (1953), Bowles (1996) e método teórico do Ministério de Fomento (2005) – mostraram-se mais sensíveis ao comprimento da raiz, enquanto os métodos voltados a estacas escavadas e raiz apresentaram maior variação com o diâmetro de perfuração.
Within the geotechnical and structural context of civil engineering, foundations are fundamental elements for the stability and performance of the superstructure. Over time, and due to degradation processes, the need for strengthening and rehabilitation has become increasingly relevant, especially in urban rehabilitation projects. In this context, the micropile—proposed by Fernando Lizzi in 1982—stands out as a deep foundation solution characterized by its small diameter, high axial load capacity, and great versatility, particularly suitable for works in restricted environments. This dissertation aims to develop a comparative and parametric analysis of foundation strengthening using micropiles. For this purpose, two calculation tools were developed in Excel, using VBA, which enable the application of structural and geotechnical analysis methodologies. The results from these tools were analyzed and compared with those obtained from the Geo5 software, to validate the proposed approaches. The first tool incorporates different structural and geotechnical design methods, allowing for a direct comparison between classical approaches found in the literature and the Geo5 software, as well as enabling parametric study evaluations. The second tool is designed to provide initial structural and geometric design estimates, based on input data such as root length or micropile diameter. The dissertation is structured into seven main chapters, covering the theoretical background of the topic, the practical development of the calculation tools, and the interpretation of the results. A total of 10 case study variations were performed to assess the influence of tubular diameter, wall thickness, free length, corrosion, drilling diameter, root length, and injection pressure. Additional cases were dedicated to validating the second tool as a support instrument for preliminary design analyses. The results highlight the differing behavior of the methods when subjected to the variations imposed by parametric study. In the structural field, the method of Jiménez Salas (1980) demonstrated greater sensitivity to geometric variations in tubular reinforcement. In contrast, Euler’s geometric method (1936) showed lower sensitivity. In the geotechnical field, some methods—Zweck (1953), Bowles (1996), and the theoretical method of the Ministry of Development (2005)—were more sensitive to the root length, whereas methods developed for bored and root piles showed greater variation in response to the drilling diameter.
Within the geotechnical and structural context of civil engineering, foundations are fundamental elements for the stability and performance of the superstructure. Over time, and due to degradation processes, the need for strengthening and rehabilitation has become increasingly relevant, especially in urban rehabilitation projects. In this context, the micropile—proposed by Fernando Lizzi in 1982—stands out as a deep foundation solution characterized by its small diameter, high axial load capacity, and great versatility, particularly suitable for works in restricted environments. This dissertation aims to develop a comparative and parametric analysis of foundation strengthening using micropiles. For this purpose, two calculation tools were developed in Excel, using VBA, which enable the application of structural and geotechnical analysis methodologies. The results from these tools were analyzed and compared with those obtained from the Geo5 software, to validate the proposed approaches. The first tool incorporates different structural and geotechnical design methods, allowing for a direct comparison between classical approaches found in the literature and the Geo5 software, as well as enabling parametric study evaluations. The second tool is designed to provide initial structural and geometric design estimates, based on input data such as root length or micropile diameter. The dissertation is structured into seven main chapters, covering the theoretical background of the topic, the practical development of the calculation tools, and the interpretation of the results. A total of 10 case study variations were performed to assess the influence of tubular diameter, wall thickness, free length, corrosion, drilling diameter, root length, and injection pressure. Additional cases were dedicated to validating the second tool as a support instrument for preliminary design analyses. The results highlight the differing behavior of the methods when subjected to the variations imposed by parametric study. In the structural field, the method of Jiménez Salas (1980) demonstrated greater sensitivity to geometric variations in tubular reinforcement. In contrast, Euler’s geometric method (1936) showed lower sensitivity. In the geotechnical field, some methods—Zweck (1953), Bowles (1996), and the theoretical method of the Ministry of Development (2005)—were more sensitive to the root length, whereas methods developed for bored and root piles showed greater variation in response to the drilling diameter.
Description
Mestrado de dupla diplomação com o Centro Federal de Educação Tecnológica de Minas Gerais – CEFET-MG
Keywords
Microestaca Ferramenta de cálculo Estrutural Geotécnico Estudo paramétrico