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Advisor(s)
Abstract(s)
O projeto sísmico de estruturas, numa perspetiva convencional, tem por base o objetivo
de se ter um tipo de comportamento que salvaguarde as vidas humanas, sem uma
preocupação na mitigação de danos. A preocupação para um comportamento dúctil e
com manutenção de integridade não incorpora questões de operacionalidade após os
eventos, com significativos impactos na vida das pessoas.
O evento sísmico de Christchurch na Nova Zelândia, ocorrido em 2011, permitiu
constatar um nível de dano sísmico com reparações economicamente inviáveis, apesar
de se ter verificado um comportamento das estruturas com capacidade dissipativa em
que as vidas foram salvaguardardes. No entanto, o nível de dano observado implicou
grandes impactos económicos e na vida das pessoas, demonstrando-se que existem ainda
questões para resolver tendo em vista a missão da Engenharia no seu serviço à sociedade,
nas diferentes vertentes. Ou seja, ficou demonstrado que existia em 2011 e continua a
existir um problema para resolver em termos de minimização dos impactos dos sismos
na vida das comunidades, apesar dos grandes avanços verificados nos últimos anos.
Na presente dissertação é apresentado um estudo acerca dos danos mais comuns,
observados após eventos sísmicos reportados na bibliografia e são descritas e analisadas
algumas soluções de mitigação. Adicionalmente, são apresentados resultados de análises
computacionais de uma estrutura com um tipo de solução para mitigação de dano,
comparando-se as perspetivas de análise tradicionais e de análise orientadas pelo
controlo do comportamento em termos do desempenho pretendido.
Para além de orientações para a conceção de sistemas estruturais de edifícios de betão
armado com mitigação de dano, baseadas na análise do comportamento, são comparadas
ferramentas de análise representativas de alguma prática de projeto e ferramentas de
natureza mais avançada, essencialmente focadas na resolução de problemas académicos.
Os resultados das análises efetuadas permitiram verificar que são viáveis soluções com
mitigação de danos com estruturas flexíveis. A flexibilidade contribui para a redução das
exigências sísmicas e permite soluções que satisfazem o critério de exigência baseado nos
deslocamentos entre pisos. O dano é mitigado com flexibilização das ligações entre vigas
e pilares, ligações descontínuas entre as paredes e as fundações, com a estabilidade
garantida por cabos pré-esforçados. As orientações de conceção deste tipo de soluções contrastam com as soluções típicas bastante mais rígidas. Esse facto tem implicações no
tipo de análise recomendado e na metodologia de avaliação da capacidade sísmica.
The seismic design of structures, in a conventional perspective, is based on the objective of defining a type of behavior that saves human lives, without a concern in mitigating damage. A concern for ductile behavior and maintenance of integrity does not incorporate issues of operability after events, with impacts on people’s lives. The Christchurch seismic event in New Zealand, which occurred in 2011, revealed a level of seismic damage with unfeasible economic repairs, despite having verified the behavior of structures with dissipative capacity in which lives are preserved. However, the level of damage observed had major economic impacts and on people’s lives, demonstrating that there are still issues to be resolved in view of Engineering’s mission to solve the problems of communities, in different aspects. In other words, it was demonstrated that there existed in 2011 and there is still a problem to solve in terms of minimizing the impacts of earthquakes on the lives of communities, despite the large certificates verified in recent years. In the present dissertation, a study is presented about the most common damages, observed in the seismic events reported in the bibliography and some mitigation solutions are described and followed. In addition, results of computational analysis of a structure with a type of solution for mitigation of damage are presented, comparing the perspectives of traditional analysis and analysis oriented by behavior control in terms of planned performance. In addition to guidelines for the design of integrated systems of reinforced concrete buildings with damage mitigation, motivated by behavior analysis, analysis tools are detected that are representative of some design practice and tools of a more advanced nature, essentially focused on problem solving. academics. The developed analyzes made it possible to conclude about the feasibility of carrying out seismic projects with damage mitigation solutions in the available calculation programs and their limitations and enabled the elaboration of a base form for the execution of similar projects.
The seismic design of structures, in a conventional perspective, is based on the objective of defining a type of behavior that saves human lives, without a concern in mitigating damage. A concern for ductile behavior and maintenance of integrity does not incorporate issues of operability after events, with impacts on people’s lives. The Christchurch seismic event in New Zealand, which occurred in 2011, revealed a level of seismic damage with unfeasible economic repairs, despite having verified the behavior of structures with dissipative capacity in which lives are preserved. However, the level of damage observed had major economic impacts and on people’s lives, demonstrating that there are still issues to be resolved in view of Engineering’s mission to solve the problems of communities, in different aspects. In other words, it was demonstrated that there existed in 2011 and there is still a problem to solve in terms of minimizing the impacts of earthquakes on the lives of communities, despite the large certificates verified in recent years. In the present dissertation, a study is presented about the most common damages, observed in the seismic events reported in the bibliography and some mitigation solutions are described and followed. In addition, results of computational analysis of a structure with a type of solution for mitigation of damage are presented, comparing the perspectives of traditional analysis and analysis oriented by behavior control in terms of planned performance. In addition to guidelines for the design of integrated systems of reinforced concrete buildings with damage mitigation, motivated by behavior analysis, analysis tools are detected that are representative of some design practice and tools of a more advanced nature, essentially focused on problem solving. academics. The developed analyzes made it possible to conclude about the feasibility of carrying out seismic projects with damage mitigation solutions in the available calculation programs and their limitations and enabled the elaboration of a base form for the execution of similar projects.
Description
Keywords
Capacidade de Deformação Capacidade Sísmica Dissipação de Energia Mitigação de Danos