Artigos de Revista
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A semi-analytical model of the 3D boundary layer over the streamlined nose of a train.
The boundary layer concept is applied to the flow around the nose of a streamlined train. In general, that flow is not axisymmetric due to the shape of the nose and the crosswind component of the relative incoming velocity. This departure from axisymmetry produces a transverse pressure gradient that is responsible for skewing an otherwise plane boundary layer. An empirical correlation, dependent on the longitudinal velocity and one unknown parameter, is used to represent the transverse velocity profile. The value of that unknown parameter is obtained from the momentum equations integrated streamwise inside the boundary layer. A visual comparison was carried out between the numerical simulations and the skin shear pattern of a scale model in a wind tunnel. The qualitative results compare well, the numerical model being able to locate the position of the main longitudinal vortices on the lee side of the train.
Ano: 2013
Número Páginas:
78-88pp.
Autor(es): Pereira, I.; André, J.M.C.S.
Revista: Journal of Wind Engineering and Industrial Aerodynamics
Editor: ELSEVIER
Keywords: Longitudinal vortices; Skewed boundary layer; Three-dimensional boundary layer; Train aerodynamics
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Experimental investigation on the seismic performance of masonry buildings using shaking table testing
Masonry buildings worldwide exhibited severe damage and collapse in recent strong earthquake events. It is known that their brittle behavior, which is mainly due to the combination of low tensile strength, large mass and insufficient connection between structural elements, is the main limitation for their structural implementation in residential buildings. A new construction system for masonry buildings using concrete blocks units and trussed reinforcement is presented here and its seismic behavior is validated through shaking table tests. Dynamic tests of two geometrically identical two-story reduced scale (1:2) models have been carried out, considering artificial accelerograms compatible with the elastic response spectrum defined by the Eurocode 8. The first model was reinforced with the new proposed system while the second model was built with unreinforced masonry. The experimental analysis encompasses local and global parameters such as cracking patterns, failure mechanisms, and in-plane and out-of-plane behavior in terms of displacements and lateral drifts from where the global dynamic behavior of the two buildings is analyzed comparatively. Finally, behavior factors for the design recommendations in case of unreinforced masonry are also evaluated.
Ano: 2013
Número Páginas:
1157
Autor(es): Campos Costa, A.; Lourenço, P.; Vasconcelos, G.; Avila, L.; Mendes, N.; Pedro Alves, J.
Revista: Bulletin of Earthquake Engineering
Editor: Springer
Volume:
Vol. 11, Issue 4.
Keywords: Shaking table; Behavior factor; Bed joint reinforcement; Seismic performance; Concrete block masonry
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Out-of-plane behaviour of a full scale stone masonry facade. Part 1: specimen and ground motion selection
The out-of-plane response of walls in existing stone masonry buildings is one of the major causes of vulnerability commonly observed in post-earthquake damage surveys. In this context, a shaking table (ST) test campaign was carried out on a full-scale masonry façade mainly focusing on the characterization of its out-of-plane overturning behaviour. The structure tested on the ST is a partial reproduction of an existing building from Azores, damaged during the 9 July 1998 Faial earthquake. The definition of the tested specimen as well as the selection of the input ground motion is reported in this paper. A specific emphasis is given to the definition of the time-history to be applied during the tests because it was felt as an essential and crucial part of the work to obtain the desired overturning behaviour. The accelerogram to be imposed was selected from a large set of accelerograms (74) by means of a step-by-step procedure on the basis of several numerical analyses resorting to the rocking response of rigid blocks.
Ano: 2013
Número Páginas:
2081
Autor(es): Campos Costa, A.; Costa, A.; Penna, A.; Arêde, A.
Revista: Earthquake Engineering & Structural Dynamics
Editor: John Wiley & Sons, Ltd.
Volume:
Vol. 42.
DOI:
10.1002/eqe.2313
Keywords: Full scale; Ground motion selection; Rocking; Masonry; Out-of-plane; Shaking table
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Out-of-plane behaviour of a full scale stone masonry façade. Part 2: shaking table tests
The present work describes a shaking table experimental campaign specifically developed for the characterisation of the out-of-plane response of a full scale stone masonry façade. After the description of the specimen and the selection of the input motion presented in a companion paper (Part 1), the experimental campaign is illustrated and extensively described. The out-of-plane behaviour of the sacco masonry façade is presented in terms of displacements, velocities, and accelerations recorded during the shaking table tests. A one-sided rocking response of the façade was observed prior to collapse. The impacts were clearly identified in the acceleration records. The façade overturning occurred with the expected failure mode, as predicted in the design of the test.Finally, some conclusions are drawn regarding the observed behaviour and particular features of this type of stone masonry constructions, which may influence the global behaviour of the façade.
Ano: 2013
Número Páginas:
2097
Autor(es): Campos Costa, A.; Penna, A.; Arêde, A.; Costa, A.; Costa, A.A.
Revista: Earthquake Engineering & Structural Dynamics
Editor: John Wiley & Sons, Ltd.
Volume:
Vol. 42, Issue 14.
DOI:
10.1002/eqe.2314
Keywords: Full scale; Ground motion selection; Rocking; Masonry; Out-of-plane; Shaking table
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Seismic energy dissipation in inelastic frames: understanding state-of-the-practice damping models
During seismic action, energy dissipation in structures occurs in structural and non-structural components, as well as in the substructure. Several of these dissipative mechanisms are modelled explicitly in nonlinear dynamic analyses, notably through relatively sophisticated hysteretic finite elements. Nevertheless, in most practical applications, it is not possible to simulate all the physical contributions to energy dissipation.Structural engineers are thus constrained to overcome this limitation by a mathematical artifice, in the form of equivalent linear viscous damping, which accounts for the remaining
Ano: 2013
Número Páginas:
148-158pp.
Autor(es): Correia, A.A.; Almeida, J.P.; Pinho, R.
Revista: Structural Engineering International
Editor: International Association for Bridge and Structural Engineering
Volume:
Vol. 23, Number 2.
Keywords: Force-based element; Inelastic frame; Damping models; Energy dissipation; Nonlinear dynamic analysis
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Simulações numéricas do comportamento de amortecedores de líquido sintonizado sujeitos a ações sísmicas
A utilização de dispositivos de dissipação de energia é vista como forma eficiente para proteger estruturas contra ações sísmicas. Os dispositivos Amortecedores de Líquido Sintonizados (ALS) são uma forma simples mas eficaz para reduzir a resposta de estruturas face a ações dinâmicas. Este artigo descreve simulações numéricas sobre o comportamento de ALS, isolados e/ou incluídos numa estrutura de transmissão, comparando-as com os resultados obtidos experimentalmente. Para o efeito foi usado um software de acesso livre denominado CLAWPACK com potencialidades para simular os fenómenos que ocorrem no interior de ALSs. O CLAWPACK consiste num conjunto de rotinas em Fortran desenvolvidas para obtenção de soluções numéricas de sistemas hiperbólicos de equações parcialmente diferenciais no tempo, como é o caso dos fenómenos não-lineares subjacentes à shallow water wave theory. Foram necessárias adaptações e ajustes em algumas das rotinas principais para permitir a simulação das excitações dinâmicas pretendidas. Nas simulações numéricas são variados alguns parâmetros, em que se incluem a altura de água, a amplitude de excitação e o número de dispositivos. Os principais resultados obtidos são comparados, com os resultados obtidos experimentalmente, tanto para dispositivos isolados como para dispositivos incluídos nas estruturas ensaiadas. As principais conclusões obtidas serão também apresentadas.
Ano: 2013
Número Páginas:
25-34pp.
Autor(es): Falcão Silva, M. J.; Campos Costa, A.; Guerreiro, L.
Revista: RPEE
Editor: LNEC
Volume:
Série II, nº 13.
Keywords: Sistemas passivos; Simulações numéricas; Mitigação de vibrações; Amortecedores de líquido sintonizado; Proteção sísmica
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A segurança sísmica na reabilitação de edifícios - Enquadramento e dimensão política
N/A
Ano: 2012
Número Páginas:
4pp.
Autor(es): Coelho, E.; Bairrão, R.
Revista: Pedra & Cal, Conservação e Reabilitação
Volume:
Nº 53.
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Gestão do risco sísmico em tubagens enterradas - O caso dos sistemas de drenagem de águas residuais
As tubagens enterradas constituem componentes principais de sistemas que permitem assegurar o bem estar e o desenvolvimento da sociedade, nomeadamente no que respeita ao abastecimento de água, à drenagem de águas residuais, ao transporte de energia e à comunicação.Com a consolidação das malhas urbanas, tem-se assistido a uma crescente preocupação, não só com a construção, mas em especial com a fase de utilização desses sistemas, tanto nas atividades de exploração (operação e manutenção) como de fim de vida (reabilitação e substituição). Adicionalmente, existe um conjunto crescente de preocupações mais vasto do que as questões operacionais correntes, que inclui os efeitos de fenómenos naturais, como os sismos. As abordagens de gestão do risco permitem ter em conta estes fenómenos e lidar explicitamente com a incerteza que lhes está associada.No contexto da problemática da gestão do risco sísmico de tubagens enterradas, apresenta-se um levantamento de modelos para avaliação da respetiva vulnerabilidade. No âmbito deste artigo é proposta uma abordagem para incorporar a variabilidade probabilística na modelação da vulnerabilidade sísmica de tubagens enterradas. Os resultados obtidos com a metodologia proposta são comparados com a gama de variação da vulnerabilidade sísmica apresentada pela American Lifelines Alliance.
Ano: 2012
Número Páginas:
4-21pp.
Autor(es): Sousa, V.; Luísa Sousa, M.; Campos Costa, A.; Matos, J. S.; Almeida, N.
Revista: Revista Águas & Resíduos
Editor: APESB
Volume:
Série III, N.º 17.
Keywords: Vulnerabilidade sísmica; Tubagem enterrada; Sistema de drenagem; Risco Sísmico
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On dynamic control of structural vibrations. Research activities conducted within the COVICOCEPAD Project
N/A
Ano: 2012
Número Páginas:
1pp.
Autor(es): Bairrão, R.
Revista: NED University Journal of Research
Volume:
Thematic Issue on Earthquakes.
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Shaking table experimental researches aimed at the protection of structures subjected to dynamic loading
N/A
Ano: 2012
Número Páginas:
6pp.
Autor(es): Bairrão, R.
Revista: The Open Construction and Building Technology Journal
Volume:
Volume 6.
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Comunicações
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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
Ano: 2009
Número Páginas:
paper 1783.
Autor(es): 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).
Ano: 2009
Autor(es): 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
Ano: 2009
Autor(es): 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
Ano: 2008
Número Páginas:
8p.
Autor(es): 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.
Ano: 2008
Número Páginas:
8p.
Autor(es): 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
Ano: 2008
Número Páginas:
8p.
Autor(es): 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
Ano: 2008
Autor(es): 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.
Ano: 2008
Número Páginas:
6p.
Autor(es): 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.
Ano: 2008
Número Páginas:
8p.
Autor(es): 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.
Ano: 2008
Autor(es): Bairrão, R.
Keywords: Damper; Vibration; Passive control; Shaking table; Tld
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Livros
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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
Ano: 2016
Número Páginas:
468p.
Autor(es): 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.
Ano: 2011
Número Páginas:
221-236pp.
Autor(es): Lemos, J. V.; Campos Costa, A.; Bretas, E. M.
Revista: 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
Ano: 2007
Número Páginas:
180p.
Autor(es): 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.
Ano: 2007
Número Páginas:
195p.
Autor(es): 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.
Ano: 1999
Número Páginas:
712-718pp.
Autor(es): Rodrigues, J.; Campos Costa, A.
Revista: 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.
Ano: 1995
Número Páginas:
165p.
Autor(es): 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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Capítulos de Livros
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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
Ano: 2019
Número Páginas:
445-458pp.
Autor(es): Silva, D. S.; Vicente, M.; Pereira, A.; Candeias, P.; Ferreira, M.A.; Oliveira, C.S.; Bernardo, R.; Lopes, M.; Henriques, P.
Revista: 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
Ano: 2018
Número Páginas:
299-309pp.
Autor(es): Gonçalves, A.; Candeias, P.; Guerreiro, L.; Ferreira, J.; Campos Costa, A.
Revista: 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.
Ano: 2018
Número Páginas:
309-321pp.
Autor(es): Ferreira, M.A.; Oliveira, C.S.; Lopes, M.; Musacchio, G; Candeias, P.; Vicente, M.; Silva, D. S.; O
Revista: 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
Ano: 2016
Número Páginas:
109-128pp.
Autor(es): Correia, A.A.; Almeida, J.P.; Pinho, R.
Revista: 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
Ano: 2009
Número Páginas:
433-454.
Autor(es): 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
Ano: 2009
Número Páginas:
233-243.
Autor(es): 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
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Shaking table testing
This text reflects the first of the four lectures that the author has presented at Udine, Italy, at CISM
Ano: 2008
Número Páginas:
165-196pp.
Autor(es): Bairrão, R.
Editor: Springer Verlag
Keywords: Shaking table testing
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Teses 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
Ano: 2009
Autor(es): 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.
Ano: 2009
Autor(es): 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
Ano: 2008
Autor(es): Candeias, P.
Keywords: Reforço sísmico; Vulnerabilidade sísmica; Ensaios sísmicos; Edifícios
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Relatórios
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Avaliação de risco sísmico do edifício Sede I da EDP - Ensaios in situ de caracterização dinâmica e do comportamento mecânico da estrutura do edifício relatório final
O presente estudo teve como objetivo a caracterização dinâmica e do comportamento mecânico da estrutura do edifício Sede I da EDP, para uma adequada simulação do seu comportamento sísmico. Neste relatório descrevem-se os ensaios de identificação dinâmica in situ realizados, com base em vibrações ambiente e em vibrações forçadas, com o objetivo de recolher informação sobre as propriedades dinâmicas da estrutura como um todo e das suas lajes dos pisos elevados em particular. Foi efetuado o registo e a análise dos sinais de aceleração devido a vibração ambiente, medidos em diversos pontos do edifício, bem como devido a vibrações forçadas impostas num dos pisos enterrados do edifício. São também apresentados e analisados os ensaios de caracterização do comportamento mecânico de componentes estruturais relacionadas com a ligação das lajes mistas dos pisos elevados às paredes dos núcleos resistentes de betão armado do edifício. Estes consistem em ensaios destrutivos de troços de laje mista ligados aos núcleos, por meio de varões selados à parede, e em ensaios de arrancamento desses varões, tendo como objetivo caracterizar os materiais e componentes dos elementos estruturais. Esta informação é essencial para a posterior calibração dos modelos numéricos da estrutura e para uma realista simulação do seu comportamento sísmico, bem como para uma eventual deteção de anomalias estruturais decorrentes de patologias que possam comprometer o desempenho do edifício face à ocorrência de sismos.
Ano: 2022
Autor(es): Correia, A.A.; Candeias, P.; Ribeiro, F.; Gomes, J. P.
Keywords: Comportamento mecânico; Ensaios in situ; Vibração ambiente; Vibração forçada; Identificação dinâmica
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Metodologia para a avaliação da segurança sísmica de edifícios existentes baseada em análises de fiabilidade estrutural - Edifícios de betão armado
A avaliação da segurança sísmica de edifícios existentes tem como quadro de referência o Eurocódigo 8
Ano: 2019
Autor(es): Sousa, R.; Campos Costa, A.; Costa, A.
Keywords: Análise de fiabilidade estrutural; Metodologias expeditas; Avaliação da segurança sísmica; Edifícios existentes
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Mapas de perigosidade sísmica para Portugal Continental: Uma análise crítica - Parte I
Nos estudos probabilísticos para avaliação da perigosidade sísmica, são estabelecidas zonas de geração sísmica (zonas sismogénicas), representando regiões que partilham as mesmas caraterísticas sismológicas, tectónicas e geológicas e definidas as relações entre a frequência com que aí ocorrem os sismos e as respetivas magnitudes, num dado período de tempo. Em 2006, para o Anexo Nacional do Eurocódigo 8, foram consideradas e caraterizadas 11 zonas Sismogénicas para Portugal continental, adaptadas de estudos previamente elaborados em 1996. Entre 2008 e 2009, no âmbito dos projetos ERSTA e SHARE, foram propostas novas zonas sismogénicas, e estimados os respetivos parâmetros da lei de frequência - magnitude. Estas diferentes propostas resultaram em diferentes mapas de perigosidade sísmica para Portugal continental. A SPES, Sociedade Portuguesa de Engenharia Sísmica, espelhando a inquietude existente na comunidade científica face às diversas expressões da perigosidade sísmica em Portugal, e consciente da necessidade de um consenso perante os agentes decisores, considerou urgente a realização de um estudo criterioso acerca das opções tomadas, nos diferentes estudos, e suas implicações. É nestecontexto que surge este trabalho, que pretende fazer uma análise crítica e comparativa dos resultadosobtidos nos diferentes estudos mencionados e as suas implicações ao nível dos períodos de retorno para sismos de maior magnitude. Numa parte II, serão estudadas as implicações em termos de valores da perigosidade sísmica, para vários períodos de retorno e frequências espetrais.
Ano: 2018
Autor(es): Carvalho, A. M.; Malfeito, N.
Keywords: Sismos; Períodos de retorno; Perigosidade sísmica
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Segurança estrutural e sísmica das construções nas intervenções de reabilitação - Enquadramento jurídico da reabilitação urbana síntese dos instrumentos jurídicos e conceitos relevantes
O presente relatório, elaborado no âmbito de um estudo em curso no LNEC sobre a segurança sísmica das construções nas intervenções de reabilitação, sintetiza os instrumentos jurídicos e os conceitos relevantes para a análise do atual regime jurídico da reabilitação urbana (RJRU), e do regime excecional de reabilitação urbana (RERU).
Ano: 2015
Autor(es): Coelho, E.
Keywords: Instrumentos legais; Reabilitação urbana; Segurança sísmica
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Assessment of innovative solutions for non
This document reports the outcomes of the research project
Ano: 2013
Autor(es): Correia, A.A.; Candeias, P.; Campos Costa, A.; Coelho, E.; Vintzileou, E.; Palieraki, V.; Lourenço, P.; Leite, J.
Keywords: Innovative test setup; Shaking table test; Wire mesh coating reinforcement; Bed joint reinforcement; Reinforced concrete frames; Non-load bearing masonry enclosures
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Seismic performance of multi-storey timber buildings - Rusticasa building
This document reports the outcome of the seismic test on the Rusticasa building, the first in a total of four buildings included in the TIMBER BUILDINGS Project. This building is a log house system (LHS). The goal of the tests was to assess the seismic performance of the building, panel elements and steel connectors, defined in terms of relative displacements and hold-down forces.
Ano: 2013
Autor(es): Campos Costa, A.; Candeias, P.; Lourenço, P.; Branco , J.; Aranha, C.
Keywords: Steel connectors; Shaking table test; Log house system (LHS); Timber buildings
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Seismic performance of multi-storey timber buildings - LegnoCase building
This document reports the outcome of the seismic test on the LegnoCase building, the second in a total of four buildings included in the TIMBER BUILDINGS Project. This building is a platform frame system with sheathing assembled by means of OSB panels (PF-OSB). The goal of the tests was to assess the seismic performance of the building, panel elements and steel connectors, defined in terms of relative displacements and hold-down forces.
Ano: 2013
Autor(es): Campos Costa, A.; Candeias, P.; Piazza, M.; Bartolucci, C.; Tomasi, R.; Grossi, P.
Keywords: Shaking table test; Steel connectors; OSB panels; Timber buildings
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Seismic performance of multi-storey timber buildings - Rubnerhaus building
This document reports the outcome of the seismic test on the RubnerHaus building, the third in a total of four buildings included in the TIMBER BUILDINGS Project. This building is a platform frame system with sheathing assembled by means of gypsum fibre panel (PF-GF). The goal of the tests was to assess the seismic performance of the building, panel elements and steel connectors, defined in terms of relative displacements and hold-down forces.
Ano: 2013
Autor(es): Campos Costa, A.; Candeias, P.; Piazza, M.; Tomasi, R.; Grossi, P.
Keywords: Shaking table test; Steel connectors; Gypsum fibre panel (PF-GF); Timber buildings
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Seismic performance of multi-storey timber buildings - TUGraz building
This document reports the outcome of the seismic test on the TUGraz building, the fourth in a total of four buildings included in the TIMBER BUILDINGS Project. This building is a cross laminated system (CTL). The goal of the tests was to assess the seismic performance of the building, panel elements and steel connectors, defined in terms of relative displacements and hold-down forces.
Ano: 2013
Autor(es): Campos Costa, A.; Candeias, P.; Schickhofer, G.; Flatscher, G.
Keywords: Shaking table test; Steel connectors; Cross laminated system (CTL); Timber buildings
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The LNEC earthquake engineering testing facility. Background information: LNEC testing facility, testing setup and protocol and data processing
The TIMBER BUILDINGS Project, led by the University of Trento, included testing of four full scale multi-story timber houses with a realistic horizontal plan and three types of timber housing systems: platform frame system (PFS), log house system (LHS) and cross laminated timber (CLT). The tests were carried in the LNEC-3D shake table under different levels of excitation and different conditions of the structure.The tests were carried with the goal of assessing the seismic performance of the buildings, panel elements and steel connectors, defined in terms of relative displacements and hold-down forces.The results were presented in separate reports, one for each building. This document contains information common to the remaining four reports.
Ano: 2013
Autor(es): Campos Costa, A.; Candeias, P.; Piazza, M.; Tomasi, R.; Lourenço, P.; Branco , J.; Schickhofer, G.; Flatscher, G.
Keywords: Equipment; Shaking Table; Timber buildings
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Outros
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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.
Ano: 2019
Autor(es): 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
Ano: 2018
Autor(es): 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
Ano: 2018
Autor(es): 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
Ano: 2017
Autor(es): Marques da Silva, F.
Keywords: Wind tunnel; Actions on structures; Wind engineering
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