Papers
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Comportamento dinâmico de paredes de frontal Pombalino reforçadas
O estudo apresentado neste trabalho teve como objetivo caracterizar experimentalmente o comportamento dinâmico de paredes de frontal Pombalino, simples e reforçadas, por meio de ensaios na mesa sísmica triaxial do Laboratório Nacional de Engenharia Civil. Os ensaios incidiram sobre dois modelos em escala real nos quais se reproduziu o comportamento de paredes de frontal pombalino, simulando dois andares. Os principais objetivos do trabalho foram: avaliar o desempenho sísmico de paredes de frontal pombalino sem reforço; avaliar o desempenho da técnica de reforço com chapas metálicas nos nós da estrutura de madeira; identificar algumas deficiências no comportamento sísmico dos edifícios pombalinos.
Year: 2016
Number Pages:
13-22pp.
Author(s): Gonçalves, A.; Candeias, P.; Guerreiro, L.; Campos Costa, A.; Ferreira, J.
: RPEE
Editor: LNEC
Volume:
Série III, N.º 2.
Keywords: Ensaios dinâmicos; Edifícios pombalinos; Mesa sísmica; Paredes de frontal
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Education: Can a bottom-up strategy help for earthquake disaster prevention?
To comply with the need to spread the culture of earthquake disaster reduction, we rely on strategies that involve education. Risk education is a long-term process that passes from knowledge, through understanding, to choices and actions thrusting preparedness and prevention, over recovery. We set up strategies for prevention that encompass child and adult education, as a bottom-up approach, from raising awareness to reducing potential effects of disruption of society. Analysis of compulsory school education in three European countries at high seismic risk, namely Portugal, Iceland and Italy, reveals that generally there are a few State-backed plans. The crucial aspects of risk education concerning natural hazards are starting age, incompleteness of textbooks, and lack of in-depth studies of the pupils upon completion of their compulsory education cycle. Hands-on tools, immersive environments, and learn-by-playing approaches are the most effective ways to raise interest in children, to provide memory imprint as a message towards a culture of safety. A video game, Treme
Year: 2016
Number Pages:
2069
Author(s): Zonno , G.; Carvalho, A. M.; Sousa, M.; Musacchio, G; Falsaperla, S; Bernhardsdóttir, A.E.; Ferreira, M.A.
: Bulletin of Earthquake Engineering
Editor: Springer
Volume:
Volume 14, Issue 7.
Keywords: Seismic hazard; Risk reduction; Risk education; Disasters prevention
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Evolution of earthquake losses in Portuguese residential building stock
The evolution of the expected earthquake losses in different Portuguese regions was studied in order to determine whether the natural regeneration of buildings could contribute to the mitigation of seismic risk, although the building exposure has increased over time in most analysed regions. To achieve this goal, five inter-related risk indicators were estimated, based on the Portuguese censuses
Year: 2016
Number Pages:
2009-2029pp.
Author(s): Luísa Sousa, M.; Campos Costa, A.
: Bulletin of Earthquake Engineering
Editor: Springer
Volume:
Vol. 14, Issue 7.
Keywords: Seismic risk mitigation; Residential building stock; Portugal; Evolution of losses; Annualized human earthquake losses; Annualized economic earthquake losses
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Experimental assessment of the out-of-plane performance of masonry buildings through shaking table tests
This article presents the results of the LNEC-3D shaking table tests on two mock-ups, Brick House and Stone House, carried out in the scope of the workshop
Year: 2016
Number Pages:
28p.
Author(s): Candeias, P.; Campos Costa, A.; Mendes, N.; Costa, A.A.; Lourenço, P.
: International Journal of Architectural Heritage. Conservation, Analysis, and Restoration
Editor: Taylor & Francis
Keywords: Stone masonry; Shaking table tests; Seismic performance; Clay brick masonry
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O desafio da previsão do comportamento fora-do-plano de edifícios existentes em alvenaria
O comportamento sísmico de estruturas existentes em alvenaria é muito condicionado pelo seu comportamento fora-do-plano, originando os chamados mecanismos locais, existindo diversas metodologias que tentam prever o comportamento deste tipo de estruturas e/ou modos de colapso.Este trabalho pretende resumir os principais resultados obtidos num evento subordinado ao tema
Year: 2016
Number Pages:
73-82pp.
Author(s): Costa, A.A.; Mendes, N.; Campos Costa, A.; Lourenço, P.
: RPEE
Editor: LNEC
Volume:
Série III, N.º 2.
Keywords: Análise numérica; Mesa sísmica; Fora-do-plano; Alvenaria
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Shaking table testing for masonry infill walls: unreinforced versus reinforced solutions
Several factors influence the behaviour of infilled frames, which have been a subject of research in the past with moderate success. The new generation of European design standards imposes the need to prevent brittle collapse of the infills and makes the structural engineer accountable for this requirement, yet it fails to provide sufficient information for masonry infills design. Therefore, the present work aims at understanding the seismic behaviour of masonry infill walls within reinforced concrete frames, using both unreinforced and reinforced solutions (bed joint reinforcement and reinforced plaster). For this purpose, three reinforced concrete buildings with different infill solutions were constructed at a scale of 1:1.5, all with the same geometry, and were tested on the shaking table of the National Laboratory for Civil Engineering, Portugal. All solutions performed adequately for the design earthquake, with no visible damage. Still, the experimental tests show that the double-leaf-unreinforced infill walls underperformed during a large earthquake, collapsing out of plane by rotating as rigid bodies with multiple configurations. Also the reinforced concrete buildings collapsed, because of the adverse interaction with the infill walls. The infill walls with bed joint reinforcement and reinforced plaster did not collapse out of plane, because of their connection to the concrete frame, which is an essential requirement.
Year: 2016
Number Pages:
2241
Author(s): Lourenço, P.; Leite, J.; Campos Costa, A.; Candeias, P.; Mendes, N.; Paulo Pereira, M.F.
: Earthquake Engineering & Structural Dynamics
Editor: John Wiley & Sons Ltd
Volume:
Vol. 45, Issue 14.
DOI:
10.1002/eqe.2756
Keywords: Earthquake engineering; Shaking table test; Reinforced plaster; Bed joint reinforcement; Reinforced concrete frames; Masonry infills
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Sheds extratores e captadores de ar: influência da geometria e da dimensão das aberturas no desempenho da ventilação natural das edificações
A ventilação natural é uma eficiente estratégia projetual para ocondicionamento térmico passivo de edificações, ocorrendo por açãodos ventos, efeito chaminé ou pela combinação de ambos. Dentre asestratégias de ventilação, destacam-se os sheds, aberturas no telhado,que funcionam como captadores ou extratores de ar, dependendo de sualocalização em relação aos ventos dominantes. O objetivo desse artigo é avaliar ainfluência da variação na geometria dos sheds e na dimensão das aberturas deentrada e saída de ar no desempenho da ventilação natural. O sistema foi avaliadopara os ângulos de incidência dos ventos externos de 0° e 45° (extração) e 135° e180° (captação). A metodologia adotada foi a simulação por Dinâmica dos FluídosComputacional (CFD), utilizando como ferramenta o software CFX. Foramrealizadas análises quantitativas (taxas de renovação de ar/hora e coeficiente depressão nas aberturas) e qualitativas (planos de contorno e vetores de direção eintensidade do fluxo de ar). Os resultados indicam que sheds com geometriasaerodinâmicas e o aumento das aberturas de saída de ar incrementam o fluxo de arinterno. Para os sheds captadores o aumento isolado das aberturas de entrada de arnão proporciona uma melhora significativa na captação dos ventos pela cobertura.
Year: 2016
Number Pages:
83-104pp.
Author(s): Lukiantchuki, M.; Shimomura, A.; Marques da Silva, F.; Caram, R.
: Ambiente Construído
Editor: Associação Nacional de Tecnologia do Ambiente Construído
Volume:
v. 16, n. 1.
Keywords: Ventilação natural; Sheds
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Simulation of shake table tests on out-of-plane masonry buildings. Part (V): Discrete element approach
The analysis of the shaking table test of a 3-wall stone masonry structure performed with a discrete element model is presented. The numerical model, created with the code 3DEC, employed a rigid block representation and a Mohr-Coulomb joint model. Joint stiffness calibration to match the experimental natural frequencies is discussed, as well as the boundary conditions to simulate the shake table. Comparisons are made with the measured displacements at key locations, and the modes of deformation and fracture of the walls. The DEM model was able to reproduce important features of the shaking table tests. The experimental deformation and near collapse patterns were clearly identifiable in the numerical simulations, which produced displacements within the observed orders of magnitude, for the various levels of excitation.
Year: 2016
Number Pages:
9p.
Author(s): Lemos, J. V.; Campos Costa, A.
: International Journal of Architectural Heritage. Conservation, Analysis, and Restoration
Editor: Taylor & Francis
Keywords: Stone masonry; Shake table test; Numerical modelling; Dynamic response; Discrete elements
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Source and high-frequency decay parameters for the Azores region for stochastic finite-fault ground motion simulations
Strong ground motion prediction based on finite-fault simulation requires the identification of the fault (strike, dip, length and width), source kinematics parameters (stress drop, rupture velocity and slip distribution), regional crustal properties (geometrical spreading, anelastic structure, and upper crustal amplification and attenuation parameters) and the determination of amplification effects due to the local site geology. The general purpose of this study is to understand source and attenuation properties in the Azores, by the determination of stress drop, quality factor and kappa, through records obtained by the Portuguese digital seismic and accelerometer network. Source Spectra were obtained, for each record, after correcting observed spectra from geometrical spreading and anelastic attenuation effect: quality factor was estimated based on coda decay in the time domain and the kappa parameter was estimated by fitting the high-frequency decay of the acceleration spectrum with a straight line in a log-linear scale. Mean stress drop value was obtained considering that
Year: 2016
Number Pages:
1885
Author(s): Carvalho, A. M.; Vales , D.; Reis , Claudia .
: Bulletin of Earthquake Engineering
Editor: Springer
Volume:
Volume 14, Issue 7.
Keywords: Attenuation; Azores; High-frequency decay; Source spectra
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A method to correct the flow distortion of offshore wind data using CFD simulation and experimental wind tunnel tests
The assessment of wind energy resource for the development of deep offshore wind plants requires the use of every possible source of data and, in many cases, includes data gathered at meteorological stations installed at islands, islets or even oil platforms - all structures that interfere with, and change, the flow characteristics. This work aims to contribute to the evaluation of such changes in the flow by developing a correction methodology and applying it to the case of Berlenga island, Portugal. The study is performed using computational fluid dynamic simulations validated by wind tunnel tests. In order to simulate the incoming offshore flow with CFD models a wind profile, unknown a priori, was established using observations from two coastal wind stations and a power law wind profile was fitted to the existing data (alfa=0.165). The results show that the resulting horizontal wind speed at 80 m above sea level is 16% lower than the wind speed at 80 m above the island for the dominant wind direction sector.
Year: 2015
Number Pages:
87-94pp.
Author(s): Silva, J.; Marques da Silva, F.; Couto, A.; Estanqueiro, A.
: Journal of Wind Engineering and Industrial Aerodynamics
Editor: Elsevier
Volume:
140.
Keywords: Wind tunnel; Cfd simulation; Wind flow over hill; Offshore wind profile
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Comunicação
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Dynamic interaction between the shaking table and the specimen during earthquake tests
The boundary conditions between the tested structures and the platform of a large shaking table are a major parameter for the design and numerical analyses of shaking table tests. A foremost attention is given to the design of the foundation and anchorage of the structure. All analyses are made considering a completely rigid shaking table: rigid actuators and rigid platform. However, since quite a long time, the shaking table / structure interaction has been clearly observed (Blondet and Esparza, 1988) when analysing the shaking table / actuators interaction, depending on the control tuning. In CEA Saclay, during the last 15 years, decreases of mock-up frequencies between calculations and experimental tests of massive structures have been observed: CASSBA, CAMUS 1 to 4, CAMUS 2000 (Combescure and Ragueneau, 2002) and more recently SMART. For a long time it has been calculated, after tests, the global stiffness that the
Year: 2009
Number Pages:
paper 1783.
Author(s): Bairrão, R.
Keywords: Earthquake; Interaction; Earthquake; Test; Shaking table
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Parâmetros das leis de Frequência-Magnitude para as Novas Zonas de Sismogénese Delineadas para a Região do Algarve
The collaborative research project ERSTA (Estudo do Risco Sísmico e de Tsunamis do Algarve), supported by ANPC (Autoridade Nacional de Protecção Civil), as given rise to a series of new developments, namely therevised seismic catalogue from IM (Instituto de Meteorologia) and the redrawing of new seismogenic zones affecting the Algarve region. It is therefore relevant to review the parameters of the Gutenberg-Richtermagnitude-frequency relation, intending to perform a future revision of the probabilistic seismic hazard analysisof the region and its disaggregation. The parameters of the Gutenberg-Richter magnitude-frequency relationships for the new seismogenic zones (IM, 2008) were estimated for unequal observation periods fordifferent magnitude ranges - determined through the analysis of the completeness of the seismic catalogue from IM - using the maximum likelihood method (Weichert, 1980).
Year: 2009
Author(s): Rodrigues, I.; Sousa, M. L.; Carvalho, A. M.; Carrilho, F.
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R&D on control of vibrations under COVICOCEPAD during 2007/08
Latest COVICOCEPAD developments
Year: 2009
Author(s): Bairrão, R.
Keywords: Base isolation; Tld; Mr dampers; Semi-active; Smart structures
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Earthquake loss estimation and mitigation in Europe: a review and comparison of alternative approaches.
The paper contributes to an assessment of the uncertainties involved in the use of current loss modeling methodologies when applied to the estimation of building damage and casualty generation in urban areas. The work derives from studies conducted within the EU-funded LESSLOSS project with the aim of providing a basis for urban planning authorities methods to assess alternative mitigation strategies. Research teams in Istanbul, Thessaloniki and Lisbon developed methods applicable to their own city and building stock. A benchmarking study was then carried out to compare the results of the three approaches when applied to a standardized
Year: 2008
Number Pages:
8p.
Author(s): Cultrera, G.; Campos Costa, A.; Luísa Sousa, M.; Spence, R.; So, E.; Ansal, A.; Pitilakis, K.; Tönük, G.; Argyroudis, S.; Kakderi, K.
Editor: International Association for Earthquake Engineering (IAEE)
Keywords: Casualties; Building damage; Ground motion; Loss estimation; Earthquake risk
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Experimental investigation on non-engineered masonry houses in low to moderate seismicity areas.
This paper presents the results of shaking table tests performed on two full-scale masonry houses typical from North-European countries. The main objective of the study was to assess the seismic behavior of such houses for situations of low to moderate seismicity, as well as to evidence the efficiency of some reinforcing details. Themain outcomes are that the value of the behavior factor ("q") for unreinforced masonry and the value of the limitslenderness of masonry panels adjacent to openings proposed by Eurocode 8 are confirmed by the experimentalresults. Furthermore, the devices proposed to improve the seismic behavior are found efficient for limiting the damages in the range of seismicity level for which they are intended but have no impact on the global collapse limitstate.
Year: 2008
Number Pages:
8p.
Author(s): Degée, H.; Candeias, P.; Campos Costa, A.; Coelho, E.; Denoël, V.
Editor: International Association for Earthquake Engineering (IAEE)
Keywords: Moderate seismicity; Low seismicity; Non-engineered housing; Masonry
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Experimental studies on the characteristics of tuned liquid dampers for reducing vibration in structures
Traditional design approaches usually consider seismic actions as equivalent static actions. Recent research has shown that adopting a dynamic approach where the real characteristics of seismic actions are taken into account may lead to reach significant behavior improvements. The inclusion of energy dissipation passive devices is nowadays seen as an effective way of improving structures protection towards seismic actions. A significant number of this kind of devices is already placed in real structures all over the world.Vibration mitigation of the seismic actions imposed to the structures is being more and more taken into account in structures design. In order to get more effective systems, structure
Year: 2008
Number Pages:
8p.
Author(s): Falcão Silva, M. J.; Campos Costa, A.
Editor: International Association for Earthquake Engineerin g (IAEE)
Keywords: Vibration mitigation; Tuned liquid dampers; Passive energy dissipation devices; Air-springs; Dynamic tests
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Performance evaluation of a reversible flow double skin facade.
Double-skin facade is an architectural/engineering solution developed from the need to increase comfort in buildings with full glazed facades. The actual concept of holistic approaches to the building energy system considers DSF as an element of an Advanced Integrated Facade. DSF were developed for colder climates and uncertainty remains on their applicability to warmer areas. Moreover there is a need for data under post-occupancy buildings in order to properly evaluate how they work from comfort and energy use points of view and to improve and validate models and predictions from design tools. Double skin facades (DSF) may show different layouts, flow path or type of ventilation (natural, mechanical or hybrid). In order to evaluate the thermal behaviour of such a facade LNEC (39º N) assembled a south facing test facility allowing changing among some of the possible configurations. Being a reversible flow type of DSF it means that it is possible to test configurations such as (according to the classification established within the IEA ANNEX 44 (Marques da Silva and Gosselin, 2006)): Outdoor Air Curtain (OAC); Indoor Air Curtain (IAC); Exhaust Air (EA), or; Supply Air (SA). It is also possible to use any kind of ventilation type, the layout being established as a box window (BW) or, as a limit, a Buffer (Bf) configuration. Some of these DSF configurations have been tested by others authors through either test cells experiments (Saelens, 2002) or field monitoring (Corgnati et al.,2003; Marques da Silva et al., 2005, 2006, 2008
Year: 2008
Author(s): Marques da Silva, F.; Pereira, I.; Pinto, A.; Gomes, M.; Rodrigues. A.
Editor: AIVC
Keywords: Double-skin facade
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Performance evaluation of advanced integrated façades in laboratory facilities.
A wide experimental campaign on transparent advanced integrated façades with a mechanically, naturally andhybrid ventilated air gap has been carried out both at the Department of Energetics at Politecnico di Torino and at Laboratório Nacional de Engenharia Civil (LNEC) in Lisbon. Measurements were performed by means of: - the TWINS (Testing Window INnovative Systems); test facility, at Politecnico di Torino; the reversible flow type DSF test cell, at LNEC. At Politecnico di Torino a mechanically ventilated climate façade and a hybrid ventilated DSF with an outdoor air curtain ventilation scheme have been investigated. At LNEC a naturally ventilated DSF with different ventilation schemes (outdoor air curtain, indoor air curtain, exhaust air, supply air or, as a limit, a buffer configuration) has been tested. The energy efficiency and thermal comfort implications of these different types of advanced integrated façade have been evaluated. Theimprovement of performance by varying configurations and operative conditions has also been investigated.
Year: 2008
Number Pages:
6p.
Author(s): Perino, M.; Zanghirella, F.; Issoglio, R.; Serra, V.; Marques da Silva, F.; Pereira, I.
Editor: AIVC
Keywords: Double-skin facade (DSF)
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Seismic zonation for portuguese national annex of Eurocode 8
The development of the Portuguese National Annexes of Eurocode 8 required the definition of a seismic zonation for Portugal. The goal of this paper is to present the applied methodology to perform the Probabilistic Seismic Hazard Analysis (PSHA) and to obtain seismic zonation for Portugal Mainland, Azores and Madeira Archipelagos. Similarly to the Portuguese code presently enforce (RSA, 1983), two scenarios were considered in PSHA computation: (i) a scenario labeled seismic action 1, characterizing earthquakes with their epicenters mainly offshore and (ii) a scenario labeled seismic action 2, referring to events with their epicenters mainly inland. The model of gross-source zones and the parameters defining seismic occurrence process in each source zone, like the Poissonian process and the exponential distribution of magnitudes, was adapted from Sousa (1996). Two different spectral attenuation laws were applied, consistent with the two above mentioned seismic scenarios, namely: (i) a recent regional attenuation law derived for Portuguese seismotectonic environment, based on a finite fault non-stationary stochastic seismological model calibrated for the region (Carvalho et al., 2008), valid for seismic action 1 and (ii) the Ambraseys et al. (1996) model, valid for seismic action 2. The PSHA was performed for all Portuguese counties and for the 475 years return period. The correspondent hazard map was used as the basis for seismic zonation. Portuguese counties were sorted according to their Housner intensity, which was used as a criterion to classify each county in a pre-defined number of seismic zones.
Year: 2008
Number Pages:
8p.
Author(s): Campos Costa, A.; Luísa Sousa, M.; Carvalho, A. M.
Editor: International Association for Earthquake Engineering (IAEE)
Keywords: National annex; Seismic hazard; Seismic zonation; Portugal; Eurocode 8; Azores
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Shaking table tests on semi-active tuned mass and tuned liquid dampers
One of the goals of the COVICOCEPAD project is to develop a mathematical model of tuned liquid dampers (TLD) devices. This new model will take into account the damping forces resisting the actions resulting from the viscous interactions between the liquid and its rigid container, the hydrodynamic head losses subsequent to orifices passing and the internal viscosity of the liquid. To calibrate the mathematical models full scale tests on shaking table are being performed. A performance evaluation of the TLD devices will be accomplished by the comparison between the behaviour of a specific structure with and without passive protection. This work addresses on the possibility of exploiting the liquid sloshing motion in tanks for specific vibration control purposes of civil engineering structures. Analytical, numerical and experimental issues are referred and the test steel frame is presented.
Year: 2008
Author(s): Bairrão, R.
Keywords: Damper; Vibration; Passive control; Shaking table; Tld
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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
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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
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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.
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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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Modelos estocásticos de rutura progressiva de falha para caracterização da ação sísmica em Portugal. Aplicação ao sismo de 1 de Novembro de 1755.
A caracterização da ação sísmica, para efeitos de projeto e verificação de segurança das estruturas de engenharia civil, é realizada para valores de intensidade sísmica elevados quando comparados com os valores de intensidade sísmica sentidos frequentemente. Tais valores elevados são compatíveis com os níveis de segurança exigidos para as estruturas, que usualmente são considerados implícitos nas regras de dimensionamento e verificação de segurança de estruturas contempladas nos códigos em vigor.
Year: 2004
Author(s): Carvalho, A. M.; Campos Costa, A.
Keywords: Modelos estocásticos; Intensidade sísmica
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Levantamento do parque habitacional de Portugal Continental para o estudo da sua vulnerabilidade sísmica com base nos censos 2001
O presente relatório, elaborado no âmbito do projecto de investigação para a Fundação para a Ciência e a Tecnologia intitulado
Year: 2003
Author(s): Luísa Sousa, M.; Martins, A.; Campos Costa, A.
Keywords: Mitigação do risco sísmico; Vulnerabilidade sísmica
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Metodologias para a avaliação de perdas humanas em consequência de sismos.
Os sismos são fenómenos naturais que apenas poderão ter consequências desastrosas se afetarem uma região habitada do globo. Sem dúvida que os piores efeitos de um desastre sísmico são as perdas de vida humana envolvidas.A redução das perdas de vidas humanas é assim um dos grandes objetivos das políticas de prevenção e proteção sísmica e do domínio de investigação da engenharia sísmica.Para se ter uma ideia da dimensão do problema refira-se que apenas no século XX (entre 1900 e o fim de 1992), o montante oficial de vítimas mortais em 1 100 sismos muito severos, atingiu o total de 1 528 000. Perto de metade deste número de vítimas ocorreu num único país, a China, e as principais contribuições para este.
Year: 2002
Author(s): Luísa Sousa, M.; Castro, S.; Campos Costa, A.
Keywords: Sismos; Perdas humanas
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Estudo de casualidade sísmica no Grupo Central do Arquipélago dos Açores
O presente relatório, elaborado no âmbito do projeto de investigação PRAXIS XXI
Year: 2001
Author(s): Luísa Sousa, M.; Carvalho, A. M.; Campos Costa, A.
Keywords: Açores; Risco sísmico
Info
Levantamento do parque habitacional de Portugal Continental para o estudo da sua vulnerabilidade sísmica com base nos censos-91
O presente relatório, elaborado no âmbito do projeto de investigação para a Fundação para a Ciência e a Tecnologia intitulado
Year: 2000
Author(s): Luísa Sousa, M.; Candeias, P.; Martins, A.; Coelho, E.; Campos Costa, A.; Cansado Carvalho, E.
Keywords: Tipologias construtivas; Vulnerabilidade à ação sísmica
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Assessment of uniform displacement spectra by probabilistic seismic hazard analysis (PSHA): Application to Lisbon. 1st year report.
The present progress report describes the research developed by LNEC under the ENVIRONMENT project ENV4-CT97-0548, entitled
Year: 1999
Author(s): Cansado Carvalho, E.; Campos Costa, A.; Luísa Sousa, M.
Keywords: RC buildings; Seismic hazard analysis
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Comportamento sísmico de condutas enterradas
O presente estudo tem por objetivo apresentar uma metodologia para a avaliação dos efeitos da propagação das ondas sísmicas em condutas de água enterradas. Essa avaliação é efetuada em termos do campo de deformações (extensões axiais e curvaturas), a serem impostas nas condutas, para diferentes valores máximos de aceleração e velocidade da ação sísmica associados a diferentes períodos de retorno.A metodologia desenvolvida é aplicada à cidade de Lisboa considerando as características locais do terreno, diversos diâmetros de tubagens e ambas as situações de condutas contínuas ou com juntas.
Year: 1998
Author(s): Campos Costa, A.; Luísa Sousa, M.
Keywords: Condutas enterradas; Ondas sísmicas
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Characterization of the new LNEC shaking table
As part of ECOEST European research activities, this report describes the experimental programme carried out at the new LNEC seismic simulator facility. It is reported a detailed characterization of the frequency response of the shaking table and the results from an assessment of its control fidelity. This information will act as a benchmark, against which the performance of future tests at this facility could be gauged.A part of the description of the procedures and results of the test programme carried out, it was also compiled descriptive material about the entire facility.
Year: 1996
Author(s): Campos Costa, A.; Gil de Morais, P.; Martins, A.
Keywords: LNEC; Shaking table
Info
Modelo histerético das relações forças-deslocamentos adequado à análise sísmica de estruturas.
O presente relatório descreve os estudos efetuados no LNEC, que visaram o desenvolvimento e implementação computacional de um algoritmo representativo das relações histeréticas forças-deslocamentos generalizados observados em ensaios de elementos de betão armado sujeitos á flexão.Foi dado um carater geral à implementação do modelo, de forma a poder ser usado em trabalhos futuros de análise dinâmica em regime não linear de estruturas de betão armado, sujeitas á ação dos sismos.O algoritmo computacional resultante é suficientemente versátil uma vez que através da introdução de alguns parâmetros pode reproduzir diferentes comportamentos estruturais, tais como: degradação de rigidez e resistência, efeito de
Year: 1987
Author(s): Costa, A.; Campos Costa, A.
Keywords: Análise sismica
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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
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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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