A madeira em estruturas antigas: diagnóstico e metodologias de intervenção estrutural. Pousada Medieval da Gralheira: caso de estudo
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2016-08-22
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Esta dissertação pretende fundamentalmente estudar as Estruturas de Madeira em Edifícios Antigos, desde a abordagem à temática da conservação e reabilitação de edifícios antigos, tendo em conta a importância do património histórico, arquitectónico, urbanístico, arqueológico, natural e cultural no sentido de estabelecer directrizes de intervenção adequadas ao contexto cultural em que se insere. Além disso apresenta-se uma perspectiva geral sobre a evolução das estruturas de madeira ao longo dos tempos, desde a pré-história até a actualidade, passando pelas principais épocas e regiões onde esta teve o papel principal. Faz-se uma referência ao material madeira atendendo à sua origem e composição, procurando demonstrar o seu papel e desempenho como material estrutural, assim como os principais tipos de degradação e expôr as fases obrigatórias de inspecção e diagnóstico, procurando encontrar formas simples e expeditas de apoiar a decisão de manutenção/reabilitação ou substituição.
Serão mencionados ainda alguns dos ensaios não destrutivos e destrutivos existentes e que se resumem, na sua maioria, à avaliação da rigidez e da capacidade resistentes dos elementos de madeira. Por fim, apresentam-se metodologias de intervenção estrutural, no que respeita a técnicas de reforço, abordando-se ainda o modo de verificação das estruturas de madeira segundo o Eurocódigo 5.
O caso de estudo desta dissertação envolve um caso concreto de estudo, nomeadamente a “Pousada Medieval da Gralheira”, no concelho de Vila Pouca de Aguiar, que reflecte uma realidade comum a uma infinidade de construções semelhantes dispersas pelas paisagens rurais de Trás-os-Montes.
Grande parte deste património construído vernáculo, encontra-se vulnerável do ponto de vista da preservação da sua integridade, face ao abandonado por parte dos seus proprietários, pois a degradação acentua-se fazendo com que as intervenções de recuperação e restauro se tornem cada vez mais complexas implicando uma componente técnica interdisciplinar altamente especializada. Assim sendo faz-se um enquadramento histórico de edifício estudado “ Pousada Medieval da Gralheira” , caracterização arquitectónica e inspecção e diagnóstico de modo a permitir o levantamento de dados relevantes à futura análise do comportamento estrutural e estado de conservação da estrutura de madeira. Com o intuito de conhecer as características mecânicas, realizou-se uma campanha de ensaios destrutivos e não destrutivos, em algumas vigas do pavimento e cobertura de madeira, cuja oportunidade surgiu pelo facto do edifício em estudo existente ter sido sujeito a uma demolição parcial por parte dos donos de obra. Os ensaios mecânicos realizados em laboratório com provetes isentos de defeitos, que resultaram da madeira retirada do pavimento, foram executados com a finalidade de determinar as propriedades físico-mecânicas da madeira, nomeadamente a massa volúmica, tensão de rotura à flexão na direcção do fio e módulo de elasticidade na direcção do fio. Em simultâneo e paralelamente a estes foram realizados ensaios não destrutivos, com recurso ao Resistógrafo e Humidímetro, de modo a avaliar o estado de conservação da madeira.
A análise do pavimento em madeira foi completada com a realização de um modelo numérico com o objectivo de analisar o comportamento da estrutura em termos de estado de limite de serviço.
São descritas técnicas de reabilitação e reforço de pavimentos de madeira, associando-as a danos ou necessidades específicas, e é feita uma análise crítica comparativa que pode ajudar a definir quais as medidas mais adequadas a cada situação. Com este trabalho pretende-se assim definir modos de actuação e avaliação de estruturas de madeira, procurando formas expeditas de apoio à decisão de intervenção, nomeadamente através de ferramentas que permitam uma avaliação simples e pouco intrusiva, mostrando que existe uma grande diversidade de soluções de reabilitação/reforço.
This dissertation aims to fundamentally study the Wood Structures in old buildings, from the approach of the issue of conservation and rehabilitation of old buildings, taking in the importance of historical, architectural, urbanistic, archaeological, natural and cultural heritage in order to establish guidelines intervention taking into account the culture and the context in which it operates. Also presents an overview of the evolution of timber structures over time, from pre-history to the present, through the major eras and regions where it had the leading role. It is a reference to lumber material given its origin and composition, seeking to demonstrate its role as a structural material and performance, as well as the main types of degradation and view required phases of inspection and diagnosis, trying to find a simple and expeditious supporting decision maintenance / rehabilitation or replacement. Are also mentioned some existing non-destructive or destructive testing and summarize them, mostly, about the evaluation of rigidity and resistant capacity of the wood elements. Finally methodologies are shown as structural intervention in the case of reinforcement techniques, there is still addressing-mode scan of timber structures according to Eurocode 5. The case study involves a concrete case study, namely "Pousada Medieval da Gralheira" in Vila Pouca de Aguiar, which reflects a common reality of a multitude of similar buildings scattered throughout the countryside of Tras-os-Montes. Much of the vernacular built heritage, is vulnerable from the point of view of preserving the integrity, given the abandoned by their owners because the degradation is accentuated making the recovery and restoration interventions become increasingly implying a complex technical and highly specialized interdisciplinary component. Therefore it is a historical framework of the studied building "Pousada Medieval da Gralheira" architectural characterization and inspection and diagnosis to allow raising relevant to future analysis of the structural behavior data and conservation status of the wooden structure. In order to meet the mechanical characteristics, there was a campaign of destructive and non-destructive testing, the pavement and wooden cover, whose opportunity arose because the building in existing study be subject to a partial demolition by the owners of work . The mechanical tests performed on laboratory specimens with no defects that resulted from the removal of the wooden floor, were performed in order to determine the physical and mechanical properties of wood, including the density, bending modulus of rupture in the direction of the wire and modulus of elasticity in the direction of the wire. Simultaneously and in parallel to these non-destructive testing, using the Resistógrafo and Humidímetro in order to assess the state of conservation of wood were performed. The analysis of the wood floor was completed with the completion of a numerical model with the aim of analyzing the behavior of the structure in terms of serviceability limit state. Rehabilitation techniques and reinforcing wooden floors are described, linking them to damages or specific needs, and a critical comparative analysis that can help to define the most appropriate measures to each situation is made. This work thus aims to define modes of operation and evaluation of wood structures, seeking expeditious decision support intervention, including through tools that allow a simple and somewhat intrusive evaluation, showing that there is a great diversity of solutions rehabilitation / strengthening.
This dissertation aims to fundamentally study the Wood Structures in old buildings, from the approach of the issue of conservation and rehabilitation of old buildings, taking in the importance of historical, architectural, urbanistic, archaeological, natural and cultural heritage in order to establish guidelines intervention taking into account the culture and the context in which it operates. Also presents an overview of the evolution of timber structures over time, from pre-history to the present, through the major eras and regions where it had the leading role. It is a reference to lumber material given its origin and composition, seeking to demonstrate its role as a structural material and performance, as well as the main types of degradation and view required phases of inspection and diagnosis, trying to find a simple and expeditious supporting decision maintenance / rehabilitation or replacement. Are also mentioned some existing non-destructive or destructive testing and summarize them, mostly, about the evaluation of rigidity and resistant capacity of the wood elements. Finally methodologies are shown as structural intervention in the case of reinforcement techniques, there is still addressing-mode scan of timber structures according to Eurocode 5. The case study involves a concrete case study, namely "Pousada Medieval da Gralheira" in Vila Pouca de Aguiar, which reflects a common reality of a multitude of similar buildings scattered throughout the countryside of Tras-os-Montes. Much of the vernacular built heritage, is vulnerable from the point of view of preserving the integrity, given the abandoned by their owners because the degradation is accentuated making the recovery and restoration interventions become increasingly implying a complex technical and highly specialized interdisciplinary component. Therefore it is a historical framework of the studied building "Pousada Medieval da Gralheira" architectural characterization and inspection and diagnosis to allow raising relevant to future analysis of the structural behavior data and conservation status of the wooden structure. In order to meet the mechanical characteristics, there was a campaign of destructive and non-destructive testing, the pavement and wooden cover, whose opportunity arose because the building in existing study be subject to a partial demolition by the owners of work . The mechanical tests performed on laboratory specimens with no defects that resulted from the removal of the wooden floor, were performed in order to determine the physical and mechanical properties of wood, including the density, bending modulus of rupture in the direction of the wire and modulus of elasticity in the direction of the wire. Simultaneously and in parallel to these non-destructive testing, using the Resistógrafo and Humidímetro in order to assess the state of conservation of wood were performed. The analysis of the wood floor was completed with the completion of a numerical model with the aim of analyzing the behavior of the structure in terms of serviceability limit state. Rehabilitation techniques and reinforcing wooden floors are described, linking them to damages or specific needs, and a critical comparative analysis that can help to define the most appropriate measures to each situation is made. This work thus aims to define modes of operation and evaluation of wood structures, seeking expeditious decision support intervention, including through tools that allow a simple and somewhat intrusive evaluation, showing that there is a great diversity of solutions rehabilitation / strengthening.
Descrição
Dissertação de Mestrado em Engenharia Civil
Palavras-chave
Estruturas de madeira , Edifícios antigos , Conservação , Reabilitação , Património histórico