Papers
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Análise não linear de um conjunto de edifícios em placa no bairro de Alvalade: avaliação preliminar de estabilidade e previsão dos mecanismos de colapso
Os edifícios tipo
Year: 2019
Number Pages:
97-106pp.
Author(s): Bernardo, V.; Candeias, P.; Campos Costa, A.; Costa, A.
: Revista Portuguesa de Engenharia de Estruturas (rpee)
Editor: LNEC
Volume:
Série III, N.º 11.
Keywords: Modos de colapso; Análise preliminar de estabilidade; Applied Element Method; Ensaios de caraterização dinâmica; Edifícios tipo
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Paredes resistentes de alvenaria de tijolo reforçadas com revestimentos armados
As construções antigas fazem parte do tecido histórico das cidades, pelo que é importante proceder a intervenções de reabilitação eficientes, mas não destruidoras da sua identidade e valor cultural intrínseco. No contexto do reforço sísmico, a utilização de rebocos armados apresenta-se como uma solução simples e pouco intrusiva. Os rebocos armados em paredes conferem um aumento da resistência e da ductilidade ao corte (no plano) e da ductilidade à flexão (fora do plano), um aumento da resistência superficial e permitem ainda um melhor controlo da fendilhação.Neste artigo será apresentada a caracterização experimental dos materiais constituintes das alvenarias (argamassas de assentamento, argamassas de revestimento e tijolos), e os resultados obtidos em ensaios de compressão diagonal de pequenos provetes de alvenaria, com e sem a aplicação de rebocos armados.
Year: 2019
Number Pages:
05-18pp.
Author(s): Mera Marques, A.; Candeias, P.; Ferreira, J.; Santos Silva, A.; Veiga, M. R.
: Revista Portuguesa de Engenharia de Estruturas (rpee)
Editor: LNEC
Volume:
Série III, N.º 10.
Keywords: Rebocos armados; Ensaios de compressão diagonal; Paredes resistentes de alvenaria
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Two-way bending out-of-plane collapse of a full-scale URM building tested on a shake table
This paper describes a shake table test on a one-storey full-scale unreinforced masonry structure, which complements an earlier testing of a two-storey structure with similar characteristics. The building specimen was meant to represent the upper floors of the end-unit of a terraced house, built with cavity walls and without any particular seismic design or detailing. In these specimens, the masonry walls were composed of two leaves: a load-bearing inner one made of calcium silicate bricks sustaining a reinforced concrete floor and an external leaf made of clay-bricks connected to the inner leaf by means of metallic ties. A pitched timber roof was supported by two triangular gable walls. Floor acceleration response histories of the previously tested two-storey specimen were used as input motions. An incremental dynamic test, with vertical and horizontal inputs, was carried out up to the explicit collapse of some bearing elements of the structure. In particular, a two-way bending out-of-plane collapse of a load-bearing wall was observed and described.
Year: 2019
Number Pages:
2165
Author(s): Correia, A.A.; Candeias, P.; Campos Costa, A.; Tomassetti, U.; Graziotti, F.
: Bulletin of Earthquake Engineering
Editor: Springer
Volume:
Vol.17.
Keywords: Vertical acceleration; Non-structural components; Timber roof; Collapse; Out-of-plane; Shake table
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Wind tunnel and CFD analysis of wind-induced natural ventilation in sheds roof building: impact of alignment and distance between sheds
Sheds roof is a natural ventilation strategy that presents roof openings working as air collectors or extractors. A detailed review of the literature indicates a lack of research analyzing the impact of different sheds roof shapes and roof configurations on natural ventilation potential. his paper aims to evaluate the impact of changes in distance and alignment between wind catcher and leeward sheds roof. The methodology was Computational Fluid Dynamics (FCD) simulation. tests were performed in a atmospheric boundary layer wind tunnel on a 1:15 scale model to evaluate the accuracy of CFD simulations in different design configurations of sheds roof. The analysis showed that CFD simulations are generaly in good agreement with the wind tunnel tests. The difference between the most o the monitored points in the two tools used had errors below 10%. besides this, the results show that changes in alignment of the sheds and increasing distance between them decrease and increase the internal airflow to the leeward and windward sheds of the roof, respectively. In the first case it is due to the reduction in the sheds openings area. In the second these changes turn the sheds more effective in the air capture.
Year: 2019
Number Pages:
22p.
Author(s): Lukiantchuki, M.; Shimomura, A.; Marques da Silva, F.; Caram, R.
: International Journal of Ventilation
Editor: Taylor & Francis
Keywords: wind tunnel; CFD; Sheds roof; Natural Ventilation
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Análise da segurança de pontes sujeitas a ações dinâmicas durante a reabilitação dos pilares
Apresenta-se neste artigo um estudo de análise da segurança das pontes Criz II e de São João de Areias, na albufeira da barragem da Aguieira, em Portugal, durante a execução de novas fundações, no âmbito das empreitadas de reabilitação, na proximidade dos pilares afetados por reações expansivas do betão no seu embasamento. A ação dinâmica induzida pela perfuração de maciços rochosos foi modelada como uma ação periódica composta por um momento torsor aplicado na fundação de cada pilar isolado combinado com três forças ortogonais representando a força imposta pela caroteadora e os desequilíbrios das tensões de corte por rotação.Através da análise dinâmica linear das estruturas completas e de análises não lineares estáticas e dinâmicas dos pilares, foram estabelecidas as condicionantes às vibrações induzidas pelas máquinas caroteadoras, nomeadamente em termos de limites máximos da resposta em velocidade no topo dos embasamentos, edefinidas as condições de monitorização da estrutura durante a obra. Estas especificações foram elaboradas em estreita colaboração com técnicos da Infraestruturas de Portugal, I.P., e incluídas nas Cláusulas Técnicas Especiais para o lançamento da empreitada.
Year: 2018
Number Pages:
05-18pp.
Author(s): Campos Costa, A.; Candeias, P.; Lemos, J. V.; Catarino, J. M.
: Revista Portuguesa de Engenharia de Estruturas (rpee)
Editor: LNEC
Volume:
Série III, N.º 8.
Keywords: Limites de vibração em embasamentos; Vibrações induzidas por caroteadoras; Análise de segurança de pontes
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Assessment of the combined in
Understanding the out
Year: 2018
Number Pages:
2821-2839pp.
Author(s): Correia, A.A.; Lourenço, P.; Onat, O.; Koçak, A.
: Earthquake Engineering and Structural Dynamics
Editor: Wiley
Volume:
47.
Keywords: Shake table experiment; Reinforced concrete; Out
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Characterization of reinforced timber masonry walls in
After the large destruction of Lisbon due to the 1755 earthquake, the city had to be completely rebuilt. The innovative
Year: 2018
Number Pages:
93-106 pp.
Author(s): Gonçalves, A.; Guerreiro, L.; Candeias, P.; Ferreira, J.; Campos Costa, A.
: Engineering Structures
Editor: Elsevier
Volume:
V. 166.
Keywords: Pombalino buildings; Seismic behavior; Dynamic tests; Timber masonry walls
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Characterization of reinforced timber masonry walls in
After the large destruction of Lisbon due to the 1755 earthquake, the city had to be completely rebuilt. The innovative
Year: 2018
Number Pages:
93-106pp.
Author(s): Gonçalves, A.; Guerreiro, L.; Candeias, P.; Ferreira, J.; Campos Costa, A.
: Engineering Structures
Editor: Elsevier
Volume:
Volume 166.
Keywords: Timber masonry walls;
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Characterization of timber masonry walls with dynamic tests
Timber-framed wall buildings are seen all over Europe, especially in seismic regions, given its adequacy to resist earthquakes. The
Year: 2018
Number Pages:
16p.
Author(s): Gonçalves, A.; Candeias, P.; Guerreiro, L.; Ferreira, J.; Campos Costa, A.
: International Journal of Architectural Heritage - Conservation, Analysis, and Restoration
Editor: Taylor&Francis
Volume:
Volume 12, 2018.
Keywords: Timber masonry walls; Shaking table; Resist earthquakes; Rehabilitation; Dynamic tests
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Characterization of timber masonry walls with dynamic tests
Timber-framed wall buildings are seen all over Europe, especially in seismic regions, given its adequacy to resist earthquakes. The
Year: 2018
Number Pages:
298-313pp.
Author(s): Gonçalves, A.; Candeias, P.; Ferreira, J.; Campos Costa, A.; Guerreiro, L.
: International Journal of Architectural Heritage
Editor: Taylor & Francis
Volume:
Vol.13.
Keywords: Timber masonry walls; Shaking table; Resist earthquakes; Dynamic tests; Rehabilitation
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Comunicação
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Equações de previsão dos movimentos sísmicos à superfície para o Arquipélago dos Açores.
Utilizam-se modelos estocásticos para a simulação dos movimentos sísmicos intensos do solopara construção de uma base de dados sintética de registos que se crêem representativos dosmovimentos do solo no Arquipélago dos Açores, no substrato rochoso.De modo a considerar a influência das condições locais do terreno, foram considerados: (i)perfis geotécnicos sintéticos, para cada tipo de terreno do Anexo Nacional do Eurocódigo 8, (ii)o modelo de propagação vertical de ondas S com polarização horizontal associado a umacoluna estratigráfica com interface inferior materializada por um semi-espaço elástico rochoso e(iii) o método linear equivalente para considerar de forma aproximada a resposta não linear dossolos.Tais simulações permitiram criar uma base de dados sintética de registos sísmicos à superfície,para as gamas de frequência, magnitude e distância hipocentral de interesse para aengenharia, permitindo a elaboração de equações de previsão dos movimentos do solo, paraos diferentes tipos de terreno referidos no Anexo Nacional do EC8, para o Arquipélago dosAçores.
Year: 2014
Number Pages:
14p.
Author(s): Carvalho, A. M.; Bilé Serra, J.; Malfeito, N.
Editor: LNEC
Keywords: Equações de Previsão de Movimentos.; Coeficientes de Atenuação; Movimentos à Superfície nos Açores; Propagação unidimensional de Energia Sísmica
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Evolution of earthquake losses in portuguese residential building stock
The objective of this paper is to analyse the evolution of expected earthquake losses in Portuguese residential buildings, to determine if their natural regeneration originates the mitigation of the seismic risk, although exposure in the region increased over time. To achieve this goal, the evolution of quantified risk measures was evaluated, based on the surveys of the residential building stock obtained in the 2001 and 2011 Portuguese census. This study provides a global perspective of the seismic risk on the Portuguese mainland, and makes possible the comparison of risk levels between different regions and epochs. The comparison of economic losses obtained in these two different moments in time, took into consideration the inflation rate, and led to the conclusion that the natural regeneration of the residential housing stock contributed to the mitigation of seismic risk, even if there was a significant increase in the exposure.
Year: 2014
Number Pages:
9p.
Author(s): Luísa Sousa, M.; Campos Costa, A.
Editor: Turkish Earthquake Foundation
Keywords: Seismic risk
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Full-scale seismic testing of modern unreinforced thermal insulation clay block masonry houses
In the scope of the transnational access activities of the European research project SERIES, the Laboratório Nacional de Engenharia Civil (LNEC) has provided access to its 3-D shaking table to the international construction company Wienerberger AG and to a group of European experts, in order to perform full-scale seismic tests on an industrial solution for buildings using a modern unreinforced thermal insulation clay block masonry structure.Such solution represents a very common construction method in Central Europe and, although there are cyclic shear test results available, its effective dynamic response under seismic events still requires experimental validation. For this purpose, two full-scale mock-ups with different geometries were tested on the 3-D shaking table using a series of seismic records with increasing intensity.This paper focuses on the most relevant experimental results regarding the structural response of the specimens, e.g., the dynamic response evolution, the collapse mechanism identified and the maximum drift values measured. The paper closes with the main conclusions drawn and with proposals for future developments.
Year: 2014
Number Pages:
12p.
Author(s): Candeias, P.; Mendes, L.; Correia, A.A.; Campos Costa, A.; Coelho, E.; Jäger, A.; Lu, S.; Degée, H.; Mordant, C.
Editor: Universidade do Minho
Keywords: Shaking table; Full-scale testing; Modern masonry
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Geração de perfis estratigráficos artificiais para o Arquipélago dos Açores.
A avaliação dos movimentos sísmicos à superfície, contemplando os efeitos de sítio, estádependente das caraterísticas geológicas dos terrenos no local em análise.Para o Arquipélago dos Açores a informação geotécnica disponível não permite umaavaliação geograficamente global da resposta sísmica dos terrenos caraterísticos destaregião.Assim, após levantamento e síntese de toda a informação disponível, foram idealizadosperfis estratigráficos sintéticos, representativos da variabilidade dos solos da região,permitindo posteriormente modelar a propagação da energia sísmica, materializada naforma de ondas de corte S, através de um meio estratificado representado por umasequência de camadas, e consequentemente, avaliar a alteração do movimento sísmicodevido à influência daquela.
Year: 2014
Number Pages:
15p.
Author(s): Carvalho, A. M.; Bilé Serra, J.; Malfeito, N.
Editor: LNEC
Keywords: Efeitos de sítio; Arquipélago dos Açores; Perfil estratigráfico
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Incertezas na simulação estocástica de sismos: o caso dos Açores.
A simulação estocástica tem sido utilizada, com algum grau de sucesso, para a obtenção deacelerogramas em zonas onde não existem muitos registos instrumentais de sismosintensos ocorridos no passado, e pode ser uma ferramenta importante nesse contexto.Contudo, essas simulações deverão, necessariamente, ser previamente validadas atravésde registos de sismos ocorridos no passado, dada a grande incerteza associada à definiçãode cenários sísmicos. É muito difícil prever qualquer um dos processos, complexos, degeração do sismo, de propagação da energia e dos efeitos locais, nomeadamente ascaracterísticas da rotura, designadamente o padrão de deslizamentos e a queda de tensãomédia no plano da falha, a atenuação das ondas sísmicas ao longo do percurso depropagação e a obtenção da amplificação local das camadas de solo superficial.Neste trabalho, são apresentados os resultados de diversas simulações estocásticas dosismo ocorrido nos Açores em 1998, considerando diferentes localizações da rotura,juntamente com os respetivos parâmetros, variação das características da atenuação ediferentes condições geológicas locais. Os acelerogramas simulados, e correspondentesespectros de resposta, foram comparados com os registos instrumentais do sismo, e com osresultados de leis de atenuação obtidas para a Europa e, em particular, para o arquipélagodos Açores.
Year: 2014
Number Pages:
12p.
Author(s): Carvalho, A. M.; Estêvão, J.M.C.
Editor: LNEC
Keywords: Sismo de 1998; Simulação estocástica; Açores
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Mechanical characterization of dry-stack interlocking compressed earth masonry
Earth has been a traditional building material to construct houses in Africa. One of the most common techniques is the use of sun dried or kiln fired adobe bricks with mud mortar. Although this technique is low-cost, the bricks vary largely in shape, strength and durability. This leads to weak houses which suffer considerable damage during floods and seismic events. A solution is the use of dry-stack masonry with stabilized interlocking compressed earth blocks (ICEB). These blocks are manufactured by compacting cement stabilized earth in a manual or hydraulic press into a mould and then air dried. The resulting blocks present uniform shapes and higher values of strength and durability. This work presents the work made in the context of the HiLoTec project. It focuses on the experimental campaign of the project to characterize the strength of ICEBs and the behaviour of dry-stack masonry.
Year: 2014
Number Pages:
12p.
Author(s): Ramos, L.; Lourenço, P.; Campos Costa, A.; Sturm, T.
Editor: Universidade do Minho
Keywords: Testing; Interlocking; Dry-stack; Compressed earth blocks; Social houses
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Poderão os blocos de terra compactada com estabilização fazer parte de um sistema sismo-resistente?
No âmbito do projeto HiLoTec (desenvolvimento de uma tecnologia construtiva simples, inovadora e sustentável para edifícios de pequeno porte em países em desenvolvimento) foi desenvolvido um sistema construtivo baseado na utilização de blocos de terra compactada com estabilização hidráulica e junta seca. O presente artigo apresenta os principais resultados do ponto de vista estrutural obtidos ao longo do projeto, com especial ênfase para o comportamento sísmico, lançando contribuições para a resposta à pergunta se se poderão os blocos de terra compactada com estabilização fazer um sistema sismo-resistente para construções de pequeno porte. A campanha experimental incluiu ensaios de caracterização do sistema a diferentes níveis: material (solo), bloco, prismas de alvenaria, paredes de alvenaria e um protótipo ensaiado na mesa sísmica no Laboratório Nacional de Engenharia Civil, em Lisboa.
Year: 2014
Number Pages:
16p.
Author(s): Campos Costa, A.; Lourenço, P.; Ramos, L.; Sturm, T.
Editor: LNEC
Keywords: Alvenaria; Blocos de terra compactada
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Processos físicos para simulação de movimentos sísmicos intensos para o arquipélago dos Açores.
A simulação de movimentos intensos do solo torna-se necessária em regiões de sismicidademoderada, onde os registos de interesse para a engenharia são escassos e insuficientes, oupara estudos que exijam especificamente registos de uma determinada magnitude edistância de interesse. O modelo estocástico, partindo do conhecimento das característicasespetrais da fonte e considerando os efeitos de propagação das ondas sísmicas no percursodesde a fonte até ao local, estima os movimentos intensos do solo em termos da suaintensidade, conteúdo em frequência duração e variabilidade espacial.Neste trabalho apresenta-se o procedimento efectuado, com base nos registos obtidos narede acelerográfica nacional, para quantificação dos parâmetros que descrevem osprocessos envolvidos na geração de movimentos intensos do solo e que são necessáriospara a aplicação do modelo estocástico. Estuda-se o processo de propagação das ondassísmicas (atenuação geométrica e inelástica), o processo de atenuação na crusta superior edeterminam-se as caraterísticas espetrais da fonte sísmica.
Year: 2014
Number Pages:
15p.
Author(s): Carvalho, A. M.; Reis, C.
Editor: LNEC
Keywords: Movimentos sísmicos; Açores; Modelos estocásticos
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Simplified wide-column model for the blind prediction shake table test of a U-shaped wall building
Reinforced concrete (RC) structures with tri-dimensional asymmetries tend to exhibit torsional effects that are of great concern in the field of earthquake engineering, in particular at large ductility levels where they become more relevant [MAN09]. In nuclear facilities, this issue assumes particular relevance considering that these structures are designed to respond essentially in the elastic range with a controlled level of deformations and accelerations when subjected to strong ground motions. Within the previous framework, the research project SMART 2013 (
Year: 2014
Number Pages:
11p.
Author(s): Correia, A.A.; Sousa, R.; Pinho, R.; Almeida, J.P.
Editor: Oxand
Keywords: Reinforced concrete; Wall; Wide-column model; Blind test; U-shaped
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Spectral-based damage identification technique on an earthen mock-up construction tested on a shaking table
Conservation of ancient built heritage plays a leading role for modern societies. Knowledge about ancient building methods, essentially based on the use of natural materials such as earth, stone and wood, is fundamental to plan interventions aimed at preserving the architectural heritage. Due to the growing research on sustainable technologies, the interest in structural systems built using natural materials has been rising more and more. Taking an earthen mock-up construction as model, the paper focuses on the dynamic behaviour of such a system tested on a shaking table. Detailed descriptions of the model, its mechanical features, the seismic test performed and the damage pattern obtained are first presented. Then, the dynamic identification of the structure during damage occurrence is performed through the decomposition of the power spectral density matrix. Damage evolution and localization are also analyzed by an index based on the complex eigenvectors estimated from the matrix. Finally, comparisons between experimental and analytical results are addressed.
Year: 2014
Number Pages:
12p.
Author(s): Lourenço, P.; Ramos, L.; Campos Costa, A.; Masciotta, M.G.; Vasta, M.; Sturm, T.
Editor: Universidade do Minho
Keywords: Earthquake; Shaking table test; Spectral-based identification technique; Damage localization; Dynamic identification; Earth construction
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Books
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Historical earthquake-resistant timber framing in the mediterranean area
This book presents a selection of the best papers from the HEaRT 2015 conference, held in Lisbon, Portugal, which provided a valuable forum for engineers and architects, researchers and educators to exchange views and findings concerning the technological history, construction features and seismic behavior of historical timber-framed walls in the Mediterranean countries. The topics covered are wide ranging and include historical aspects and examples of the use of timber-framed construction systems in response to earthquakes, such as the gaiola system in Portugal and the Bourbon system in southern Italy; interpretation of the response of timber-framed walls to seismic actions based on calculations and experimental tests; assessment of the effectiveness of repair and strengthening techniques, e.g., using aramid fiber wires or sheets; and modelling analyses. In addition, on the basis of case studies, a methodology is presented that is applicable to diagnosis, strengthening and improvement of seismic performance and is compatible with modern theoretical principles and conservation criteria. It is hoped that, by contributing to the knowledge of this construction technique, the book will help to promote conservation of this important component of Europe
Year: 2016
Number Pages:
468p.
Author(s): Cruz, H.; Saporiti Machado, J.; Campos Costa, A.; Candeias, P.; Catarino, J. M.
Editor: Springer
Volume:
Vol. 1.
Keywords: Heart 2015 Conference; Historic Masonry; Performance-based Assessment; Structural Health Monitoring; Timber-Framed Construction Systems; Seismic-Resistant Timber Frames; Historical Constructive Analysis; Historical Timber-Framed Walls
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Assessment of the seismic capacity of stone masonry walls with block models
The applications of discrete elements models based on rigid block formulations to the analysis of masonry walls under horizontal out-of-plane loading is simplified block pattern are addressed. Two procedures for creating irregular block systems are presented, one using Voronoi polygons, the other based on a bed and cross joint structure with random deviations. A test problem provides a comparison of various regular and random block patterns, showing their influence on the failure loads. The estimation of manual frequencies of rigid block models, and its application to static pushover analyses, is addressed. An example of application of rigid block model to wall capacity problem is presented.
Year: 2011
Number Pages:
221-236pp.
Author(s): Lemos, J. V.; Campos Costa, A.; Bretas, E. M.
: Computational Methods in Earthquake Engineering
Editor: Springer
Volume:
Vol. 21.
Keywords: RTigid blocks; Discrete elements; Seismic assessment; Masonry structures
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Earthquake disaster scenario prediction and loss modelling for urban areas
The overall aim of Sub-Project 10 (Earthquake disaster scenario predictions and loss modelling for urban areas) has been to create a tool, based on state-of-the-art loss modelling software, to provide strong, quantified statements about the benefits of a range of possible mitigation actions, in order to support decision-making by urban authorities for seismic risk mitigation strategies. A further larger aim has been to contribute to a seismic risk mitigation policy for future implementation at European level. Among the European cities for which loss estimation studies have been carried out are Istanbul, Lisbon and Thessaloniki, and tools, using GIS mapping, have been developed by research teams in each of these cities; these were made available for further development to examine mitigation strategies within SP10. Related research studies
Year: 2007
Number Pages:
180p.
Author(s): Campos Costa, A.; Carvalho, A. M.
Editor: IUSS Press
Keywords: Shaking scenarios
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European manual for in-situ assessment of important existing structures. LessLoss Sub Project 5-In-situ assessment, monitoring and typification of buildings and infrastructure
Much work in Earthquake Engineering was devoted to the improvement of earthquake resistant design of new structures. One European result is EN 1998, which will be in several years the main seismic code for all European countries. But it is well known, that older existing structures cause in many large earthquakes much more casualties and damages than new structures. It is certainly not possible to retrofit all existing structures, but agreement exists, that assessment and retrofit of safety - critical - structures and lifeline structures must have priority. In September 2004 the European Integrated Research Project LESSLOSS on Risk Mitigation for Earthquakes and Landslides was started. The project will run for three years and comprises 13 Sub-Projects (SP´s). The consortium consists of 46 partners (see http:\\www.lessloss.org). LESSLOSS SP5 is on In-situ Assessment, Monitoring and Typification of buildings and Infrastructure. The project partners of SP5 are ARS, CESI, LNEC, RWTH and VCE. This Sub Project focuses mainly on the assessment of important existing structures and tries to integrate experimental methods into the assessment procedure. The progress of SP5 obtained in the first year is summarized in this paper. Highlights presented by all partners are mentioned and the assessment of Hospital Innsbruck is presented in more detail. The most innovative task of LESSLOSS/ SP5 is Update of vulnerability estimates via monitoring, which was also started in the first year.
Year: 2007
Number Pages:
195p.
Author(s): Campos Costa, A.; Candeias, P.; Mendes, L.; Flesch, R.; Pellegrini, R.; Friedl, H.; Hoffmeister, B.; Oppe, M.; Veit-Egerer, R.; Wenzel, H.; Eusebio, M.
Editor: IUSS Press
Keywords: Structures; Earthquake
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Modal analysis from ambient vibration survey of bridges: LNEC experience
In order to study the behavior of bridge structures in relation to traffic, wind and seismic loads, it is extremely important to know their actual dynamic properties (natural frequencies, vibration mode shapes and damping). The experimentally identified dynamic properties of bridge structures are also an effective way to characterize their actual global structural behavior. Whether included in the reception load tests of recently built bridges, before they are opened to the traffic, or as part of the inspection works of bridges already in service, LNEC has performed modal analysis studies based on the results of ambient vibration tests. Some of the studies carried out recently in important bridges are reported in this paper.
Year: 1999
Number Pages:
712-718pp.
Author(s): Rodrigues, J.; Campos Costa, A.
: Proceedings of the 17th International Modal Analysis Conference : February 8 - 11, 1999 / IMAC XVII.
Editor: SEM
Volume:
Vol. 3727.
Keywords: Dynamic properties; Bridge structures
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O Sismo de Northridge, Los Angeles, de 17 Janeiro de 1994. Ensinamentos para Portugal.
O sismo de Northridge ocorreu na parte norte da área metropolitana de Los Angeles, Califórnia, às 4:31 h do dia 17 de janeiro, uma segunda-feira coincidente com dia de feriado nacional, tendo atingindo uma magnitude de 6.6 na escala de Richter. O número total de vítimas mortais cifra-se em 57, havendo para cima de 8 000 feridos e 20 000 desalojados.As estimativas de perdas totais, feitas em meados de fevereiro de 1994, apontavam para valores de 15 biliões de US dólares, tendo o Estado da Califórnia apresentado um impacto económico total de ordem dos 30 biliões de dólares, perto do valor do Orçamento Geral do estado Português para 1994. Os prejuízos infligidos na indústria e no comércio são também surpreendentemente elevados, exigindo longos períodos de interrupção das atividades económicas.
Year: 1995
Number Pages:
165p.
Author(s): Oliveira, C.S.; Costa, A.; Campos Costa, A.; Azevedo, J.; Delgado, R.M.
Editor: IST e FEUP
Keywords: Northridge earthquake; Earthquake effects
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Capítulo de Livro
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Shaping favorable beliefs towards seismic protection through risk communication: A pilot-experience in two Lisbon schools (Portugal).
Communicating science within disaster risk reduction using methods that encourage two-way dialogue between scientists and laypersons is a challenging task. This paper aims at presenting a methodological strategy of communicating risk and non-structural seismic protection measures through participatory approach. Such methodological strategy is part of a pilot experience of risk communication in two schools in Lisbon (Portugal) under the EU project KnowRISK (Know your city, Reduce seISmic risK through non-structural elements). The efficacy of education for seismic safety is often inhibited by an incomplete understanding of the process by which individuals decide to protect themselves from harm (Becker JS, Paton D,Johnston DM, Ronan KR. Nat Hazards 64(1):107
Year: 2019
Number Pages:
445-458pp.
Author(s): Silva, D. S.; Vicente, M.; Pereira, A.; Candeias, P.; Ferreira, M.A.; Oliveira, C.S.; Bernardo, R.; Lopes, M.; Henriques, P.
: Proceedings of the International Conference on Earthquake Engineering and Structural Dynamics
Editor: Springer Link
Volume:
Volume 47.
Keywords: Non-structural; Protective behaviours; Risk communication; Seismic risk
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Characterization of timber masonry walls with dynamic tests
Most of the Lisbon 18th century timber-framed masonry
Year: 2018
Number Pages:
299-309pp.
Author(s): Gonçalves, A.; Candeias, P.; Guerreiro, L.; Ferreira, J.; Campos Costa, A.
: Historical earthquake-resistant timber framing in the mediterranean area
Editor: Springer
Volume:
Vol. 1.
Keywords: Shaking table tests; Timber-masonry walls;
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KnowRISK practical guide for mitigation of seismic risk due to non-structural components
Good performance of non-structural elements can be decisive in saving lives and costs when an earthquake strikes. The European project KnowRISK aims to educate and encourage households to take the necessary precautionary measures to protect people, houses, and contents. Preparedness and prevention act on community resilience. Within the KnowRISK project, the idea of a Practical Guide has been conceived suggesting seismic mitigation solutions for non-structural components to non-experts stakeholders. It is intended to guide people into the first steps of prevention in a straightforward manner, minimizing or avoiding injuries, damage, and long-term financial consequences. The novelty of the Guide belongs to his philosophy: a path through increasing challenges corresponds to a growing level of safety. The idea is that anyone can mitigate seismic risk in its own environment by adopting simple and low cost measures. The Practical Guide may contribute to increase risk awareness. This kind of initiatives if undertaken at larger scales may also enhance social resilience.
Year: 2018
Number Pages:
309-321pp.
Author(s): Ferreira, M.A.; Oliveira, C.S.; Lopes, M.; Musacchio, G; Candeias, P.; Vicente, M.; Silva, D. S.; O
: Proceedings of the International Conference on Earthquake Engineering and Structural Dynamics
Editor: Springer Link
Volume:
Volume 47.
Keywords: Practical guide; Community resilience; Preparedness; Non-structural elements
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Elastic and inelastic analyses of frames with a force-based higher-order 3D beam element accounting for axial-flexural-sheartorsional interaction
When one of the dimensions of a structural member is not clearly larger than the two orthogonal ones, engineers are usually compelled to simulate it with refined meshes of shell or solid finite elements that typically impose a large computational burden. The alternative use of classical beam theories, either based on Euler-Bernoulli or Timoshenko
Year: 2016
Number Pages:
109-128pp.
Author(s): Correia, A.A.; Almeida, J.P.; Pinho, R.
: Computational Methods in Applied Sciences
Editor: Springer
Volume:
Vol. 3.
Keywords: Inelastic response; Boundary conditions; Flexural-shear-torsional interaction; Higher-order; Force-based; Beam element
Info
A finite-fault modeling of the 1755 Lisbon earthquake sources
A non
Year: 2009
Number Pages:
433-454.
Author(s): Carvalho, A. M.; Campos Costa, A.; Sousa Oliveira, C.
Editor: L.A. Mendes-Victor et al. (eds)
Keywords: Earthquake scenarios; Finite-fault modeling
Info
Simulating earthquake scenarios in the european project Lessloss: the case of Lisbon
N/A
Year: 2009
Number Pages:
233-243.
Author(s): Zonno, G.; Carvalho, A. M.; Franceschina, G.; Akinci, A.; Campos Costa, A.; Coelho, E.; Cultrera, G.; Pacor, F.; Pessina, V.; Cocco, M.
Editor: L.A. Mendes-Victor et al. (eds)
Keywords: Earthquake scenarios
Info
Shaking table testing
This text reflects the first of the four lectures that the author has presented at Udine, Italy, at CISM
Year: 2008
Number Pages:
165-196pp.
Author(s): Bairrão, R.
Editor: Springer Verlag
Keywords: Shaking table testing
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Tese de Doutoramento
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Modelos estocáticos para a caracterização da acção sísmica em Portugal Continental
Um dos principais problemas e interesses da engenharia sísmica é a caracterizaçãoda acção sísmica, envolvendo a estimativa da intensidade, conteúdo em frequência,duração e variabilidade espacial dos movimentos intensos do solo mais gravosos, emtermos dos seus efeitos nas estruturas, que pode ocorrer num local.O presente trabalho de investigação desenvolve e aplica a metodologia estocástica etécnicas de modelação de fonte
Year: 2009
Author(s): Carvalho, A. M.
Keywords: Portugal continental; Risco sísmico; Fonte sísmica; Modelos estocásticos; Acção sísmica
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Risco sísmico em Portugal Continental
Os sismos são encarados frequentemente como desastres naturais inevitáveis. Todavia,deveriam ser considerados fenómenos naturais, cujos efeitos adversos podem ser minimizadoscaso se proceda a uma gestão efectiva do risco sísmico.O objectivo principal do presente trabalho de investigação é o de avaliar o risco sísmicoem Portugal Continental.Sendo um tema de natureza multidisciplinar, apresentam-se e discutem-se modelos deavaliação probabilística da perigosidade sísmica e sua desagregação, de vulnerabilidade efragilidade sísmicas de tipologias construtivas, de danos e de perdas económicas e humanas.Aplica-se a análise probabilística da perigosidade sísmica, e sua desagregação, aPortugal Continental, obtendo-se cenários modais capazes de reproduzir os níveis deperigosidade que os condicionam. Apresenta-se o inventário do parque habitacional e seushabitantes, descriminado por factores de vulnerabilidade, e classifica-se a sua vulnerabilidadesegundo os modelos de dano. Procede-se à actualização e aferição de uma metodologia parasimulação de cenários sísmicos, integrada num Sistema de Informação Geográfico. Avalia-seo risco sísmico, seguindo diversas abordagens, comparando-se os resultados com o risco deoutros países.Construiu-se assim uma ferramenta de avaliação de perdas devidas a sismos, queconstitui uma primeira contribuição para o desenvolvimento de um processo de gestão dorisco sísmico aplicado ao Continente Português.
Year: 2009
Author(s): Sousa, M. L.
Info
Avaliação da vulnerabilidade sísmica de edifícios de alvenaria
O parque habitacional de Portugal Continental contém algumas tipologias construtivas deelevada vulnerabilidade sísmica em relação às quais urge actuar no sentido de reduzir o riscosísmico a elas associado. No projecto de investigação
Year: 2008
Author(s): Candeias, P.
Keywords: Reforço sísmico; Vulnerabilidade sísmica; Ensaios sísmicos; Edifícios
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Relatório Científico
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LNEC-SPA, signal processing and analysis tools for civil engineers - Version 1.0
N/A
Year: 2007
Number Pages:
78pp.
Author(s): Mendes, L.; Campos Costa, A.
Info
Loss estimations for a reference situation
This report addresses the National Laboratory for Civil Engineering (LNEC) participation in Subproject 10 Earthquake disaster scenario predictions and loss modelling for urban areas. More precisely this report was developed in order to accomplish the 24 months LESSLOSS deliverable nº 85, which achieves loss estimates for the Metropolitan Area of Lisbon (MAL), for pre-defined scenarios earthquake. These loss estimations represent the reference situation to be compared with revised loss estimates after implementing mitigation actions with the ultimate goal of being established, in the next deliverable, the
Year: 2007
Author(s): Campos Costa, A.; Luísa Sousa, M.; Carvalho, A. M.
Keywords: Risk mitigation for earthquakes
Info
Loss estimations for a reference situation - Application to Lisbon Metropolitan Area
N/A
Year: 2007
Number Pages:
54pp.
Author(s): Campos Costa, A.; Sousa, M. L.; Carvalho, A. M.
Info
PROJECT NEFOREEE
N/A
Year: 2007
Number Pages:
189pp.
Author(s): Silva, M. J.; Bairrão, R.
Info
RELATÓRIO DE ACTIVIDADE DO PROJECTO USUET
N/A
Year: 2007
Number Pages:
60pp.
Author(s): Sousa, M. L.; Afonso, N.
Info
Enhancing seismic resistance and durability of natural masonry stone- Construction and 1st phase of the experimental program
The present report describes the construction of a model in limestone masonry for the user Group 3 oh the ECOLEADER Project, led by IRIDEX Construction Group, and the first phase of the experimental program developed in LNEC. The description of the construction, a photographic report and the results obtained on the characteristics tests made on the mortars used in the construction are presented.The construction was carried out by contractor José dos Santos Paixão on the basics of model details and materials specifications proposed by the User group 3, being NESDE/LNEC responsible for the guidance and supervision of the works.
Year: 2006
Author(s): Falcão Silva, M. J.; Candeias, P.; Campos Costa, A.; Bairrão, R.
Keywords: Ecoleader; Limestone masonry
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Shaking table tests of a reinforced concrete precast building system.
This report describes the first phase activity of the Portuguese group in the Precast Structures EC8 research projet. The Portuguese group is composed by Laboratório Nacional de Engenharia Civil (LNEC) and the Civibral, S.A. Precast Company.In this phase, seismic test were made in the LNEC
Year: 2006
Author(s): Mendes, L.; Coelho, E.; Campos Costa, A.
Keywords: Reinforced concrete; Shaking table tests
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Building stock inventory and vulnerability data for Lisbon Metropolitan Area
The present report addresses the first twelve months of LNEC participation in LESSLOSS
Year: 2005
Author(s): Campos Costa, A.; Luísa Sousa, M.; Coelho, E.
Keywords: Risk mitigation for earthquakes; Vulnerability
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Dinámica de bloques de piedra.
The dynamics of rigid bodies was studies by long time, because this phenomenon is important in the seismic security of some types of structures. However, there are few experimental studies. This job shows the experimental test carried out at the Laboratório Nacional de Engenharia Civil (LNEC) of Portugal. Four blue granites stones were tested, each one with different geometrical characteristics, under harmonic and random motions.A numerical simulation was carried out with the Discrete Element Method (DEM). This method has shown to be a good tool in the study of the dynamics of rigid bodies. It was proposed a new methodology to find the parameters of the DEM by using the parameters of classical theory.
Year: 2005
Author(s): Peña, F.; Campos Costa, A.; Lemos, J. V.
Keywords: Discrete Element Method (DEM); Dynamics of rigid bodies
Info
Seismic risk mitigation options and actions to be studied for Lisbon Metropolitan Area
The project LESSLOSS
Year: 2005
Author(s): Luísa Sousa, M.; Coelho, E.; Campos Costa, A.
Keywords: Seismic risk mitigation; Lisbon Metropolitan Area
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Outro
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Sensibilidade climática, capacidade adaptativa e de vulnerabilidades atuais e futuras da AML
Análise dos registos históricos de eventos climáticos e o seu impacto no setor da energia da AML, para identificar o grau em que este setor foi afetado por estímulos relacionados com o clima. Avaliação de capacidades adaptativas.
Year: 2019
Author(s): Marques da Silva, F.; Pinto, A.; Machado, P.
Keywords: Energia; Alterações climáticas
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A propósito da forma na engenharia do vento
Análise da forma das edificações nas ações do vento
Year: 2018
Author(s): Marques da Silva, F.
Keywords: Engenharia do vento; Aerodinãmica
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Forma e desenho urbano - efeitos na ventilação
As condicionantes arquitetónicas e de urbanização na ventilação natural
Year: 2018
Author(s): Marques da Silva, F.
Keywords: Engenharia do vento; Ventilação
Info
Wind and structures
Caracterização do vento. Ações sobre estruturas. Ensaios em túnel de vento
Year: 2017
Author(s): Marques da Silva, F.
Keywords: Wind tunnel; Actions on structures; Wind engineering
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