Caraterização e análise sísmica da passagem superior do Campo Grande
Miniatura indisponível
Data
2018
Título da revista
ISSN da revista
Título do Volume
Editora
Resumo
Um sismo manifesta-se por libertações de energia a partir do interior da terra, obtidas pelo movimento das placas tectónicas. A este fenómeno reúne-se um conjunto de caraterísticas, tais como: frequência, localização, magnitude e intensidade, que são registadas ao longo de um período de tempo numa dada região. A correta quantificação da ação sísmica, bem como a correta definição dos efeitos da mesma nas estruturas, são importantes para evitar o colapso das mesmas durante a ocorrência de sismos bem como para garantir um bom comportamento das mesmas durante a ocorrência de sismos de magnitude moderada. O Eurocódigo 8 quantifica a ação sísmica numa dada região e preconiza metodologias de dimensionamento (mais detalhadas em comparação ao RSA e REBAP), que vêm ajudar na obtenção de resultados mais refinados relativamente aos comportamentos dinâmico e sismo-resistente das estruturas.
Assim, no presente trabalho foi feita uma análise sísmica à Passagem Superior Pedonal (PSP) do Campo Grande, situada junto à Universidade Lusófona de Humanidades e Tecnologias, recorrendo à utilização de um programa de cálculo automático de estruturas, visto que atualmente este tipo de ferramentas são fundamentais para a análise e o dimensionamento de estruturas.
A análise sísmica consistiu nas seguintes fases: (i) desenvolvimento de modelos numéricos de elementos finitos para a fase de projeto e para a fase de serviço, devidamente calibrados de acordo com os resultados obtidos da análise modal experimental efetuada na PSP; (ii) comparação da resposta do tabuleiro sob diversos registos sísmicos obtidos nas últimas décadas; foram obtidos espetros de resposta para cada cenário e confrontados com os espetros de resposta regulamentares; (iii) comparação das acelerações espetrais elásticas de acordo com o RSA e EC8, bem como dos esforços internos, de acordo com as condições de massa e rigidez da estrutura definidas em projeto e em serviço; e (iv) verificação da segurança das ligações do tabuleiro aos pilares.
An earthquake is manifested by releases of energy from the interior of the earth, obtained by the movement of tectonic plates. This phenomenon includes a set of characteristics such as: frequency, location, magnitude and intensity, which are recorded over a period of time in a given region. The correct quantification of the seismic action, as well as the correct definition of the effects of the same in the structures, are important to avoid the collapse of the structures during the occurrence of exceptional earthquakes as well as to guarantee a good behavior of the same ones during the occurrence of earthquakes of moderate magnitude. Eurocode 8 quantifies the seismic action in a given region and recommends sizing methodologies (more detailed in comparison to RSA and REBAP), which help to obtain more refined results regarding the dynamic and earthquake-resistant behavior of the structures. Thus, in the present work a seismic analysis was made to the Pedestrian overpass (PO) of Campo Grande, located next to the Lusófona University of Humanities and Technologies, using a program of automatic calculation of structures, since these are currently fundamental tools for the analysis and the dimensioning of structures. The seismic analysis consisted of the following phases: (i) development of numerical models of finite elements for the design phase and for the service phase, duly calibrated according to the results obtained from the experimental modal analysis carried out in the PO; (ii) comparison of the response of the board under several seismic records obtained in the last decades; response spectra were obtained for each scenario and were compared with regulatory response spectra; (iii) comparison of elastic sprung accelerations according to RSA and EC8, as well as internal stresses, according to the conditions of mass and rigidity of the structure defined in design and in service; and (iv) checking the safety of the tray connections to the abutments.
An earthquake is manifested by releases of energy from the interior of the earth, obtained by the movement of tectonic plates. This phenomenon includes a set of characteristics such as: frequency, location, magnitude and intensity, which are recorded over a period of time in a given region. The correct quantification of the seismic action, as well as the correct definition of the effects of the same in the structures, are important to avoid the collapse of the structures during the occurrence of exceptional earthquakes as well as to guarantee a good behavior of the same ones during the occurrence of earthquakes of moderate magnitude. Eurocode 8 quantifies the seismic action in a given region and recommends sizing methodologies (more detailed in comparison to RSA and REBAP), which help to obtain more refined results regarding the dynamic and earthquake-resistant behavior of the structures. Thus, in the present work a seismic analysis was made to the Pedestrian overpass (PO) of Campo Grande, located next to the Lusófona University of Humanities and Technologies, using a program of automatic calculation of structures, since these are currently fundamental tools for the analysis and the dimensioning of structures. The seismic analysis consisted of the following phases: (i) development of numerical models of finite elements for the design phase and for the service phase, duly calibrated according to the results obtained from the experimental modal analysis carried out in the PO; (ii) comparison of the response of the board under several seismic records obtained in the last decades; response spectra were obtained for each scenario and were compared with regulatory response spectra; (iii) comparison of elastic sprung accelerations according to RSA and EC8, as well as internal stresses, according to the conditions of mass and rigidity of the structure defined in design and in service; and (iv) checking the safety of the tray connections to the abutments.
Descrição
Orientação: Elói João Faria Figueiredo ; co-orientação: Ana Isabel Mera Marques
Palavras-chave
MESTRADO EM ENGENHARIA CIVIL, ENGENHARIA CIVIL, CIVIL ENGINEERING, MÉTODO DE ELEMENTOS FINITOS, FINITE ELEMENT METHOD, AÇÃO SÍSMICA, SEISMIC ACTION, DINÂMICA DE ESTRUTURAS, STRUCTURAL DYNAMICS, RISCO SÍSMICO, SEISMIC RISK, LISBOA, LISBON, ANÁLISE SÍSMICA, SEISMIC ANALYSIS