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Decisions to mitigate seismic risk require a consistent approach to evaluate the effects of future earthquakes on population, on civil engineering structures and infrastructures.The mathematical and probabilistic methods that are the support to those approaches are generally called Risk Analysis; in the particular case of seismic events andmitigation strategies it will be named Seismic Risk and Mitigation Analysis, SRMA. The paper will address the subject of estimating the seismic risk and evaluate mitigation strategies for the existing building stock of the metropolitan area of Lisbon by describing the methods and showing preliminary results obtained with LNECloss numerical tool. Even though such a sophisticated tool needs validation on some parameters to become more reliable, it is shown that it is possible to compare results of different mitigation strategies.

This paper describes the shaking table tests, and their main results, of an asymmetric limestone masonry building, under different reinforcement conditions. The work was performed in the aim of the project

No âmbito de um projecto denominado

In this study, we simulate and compare ground motion shaking in the city of Lisbon and surrounding counties (metropolitan area of Lisbon (MAL)), using two possible earthquake models: the onshore source area of Lower Tagus Valley, M5.7 and M4.7 and the offshore source area, Marques de Pombal Fault, M7.6, one of the possible source of the 1755 Lisbon earthquake. The stochastic and a new hybrid stochastic-deterministic approach (DSM) are used in order to evaluate the ground shaking and to characterize its spatial variability. Results are presented in terms of response acceleration spectra (PSA) and peak ground acceleration (PGA) with respect to bedrock and surface. Site effects are evaluated by means of equivalent stochastic non-linear one-dimensional ground responses analysis, performed for a set of stratified soil profile units properly designed to cope with the soil site conditions of MAL region. A sensitive study is carried out using different input parameters and different approaches in order to give the basic information to evaluate the range of uncertainty in seismic scenarios.

In this study, we simulate and compare ground motion shaking in the city of Lisbon and surrounding counties (metropolitan area of Lisbon (MAL)), using two possible earthquake models: the onshore source area of Lower Tagus Valley, M5.7 and M4.7 and the offshore source area, Marques de Pombal Fault, M7.6, one of the possible source of the 1755 Lisbon earthquake. The stochastic and a new hybrid stochastic-deterministic approach (DSM) are used in order to evaluate the ground shaking and to characterize its spatial variability.Results are presented in terms of response acceleration spectra (PSA) and peak ground acceleration (PGA) with respect to bedrock and surface. Site effects are evaluated by means of equivalent stochastic non-linear one-dimensional ground responses analysis, performed for a set of stratified soil profile units properly designed to cope with the soil site conditions of MAL region. A sensitive study is carried out using different input parameters and different approaches in order to give the basic information to evaluate the range of uncertainty in seismic scenarios.

This article describes the dynamical behavior of free-standing block structures under seismic loading. A comprehensive experimental investigation has been carried out to study the rocking response of four single blocks of different geometry and associations of two and three blocks. The blocks, which are large stones of high strength blue granite, were subjected to free vibration, and harmonic and random motions of the base. In total, 379 tests on a shaking table were carried out in order to address the issues of repeatability of the results and stability of the rocking motion response. Significant understanding of the rocking motion mechanism is possible from the high quality experimental data. Extensive experimental measurements allowed to discuss the impulsive forces acting in the blocks and the three-dimensional effects presented in the response.

Stone masonry in historical buildings. Ways to increase their resistance and durability

This paper describes the behavior of single rigid-block structures under dynamic loading. A comprehensive experimental investigation has been carried out to study the rocking response of four blue granite stones with different geometrical characteristics under free vibration, and harmonic and random motions of the base. In total, 275 tests on a shaking table were carried out in order to address the issues of repeatability of the results and stability of the rocking motion response. Two different tools for the numerical simulations of the rocking motion of rigid blocks are considered. The first tool is analytical and overcomes the usual limitations of the traditional piecewise equations of motion through a Lagrangian formalism. The second tool is based on the discrete element method (DEM), especially effective for the numerical modeling of rigid blocks. A new methodology is proposed for finding the parameters of the DEM by using the parameters of the classical theory. An extensive comparison between numerical and experimental data has been carried out to validate and define the limitations of the analytical tools under study.

A caracterização do parque habitacional existente em Portugal Continental no que respeita à sua vulnerabilidade sísmica e a sua classificação em tipologias construtivas são os principais objetivos do presente artigo.Esta caracterização e classificação estão enquadradas num estudo de âmbito mais vasto que é o de avaliação do risco sísmico de Portugal Continental [Sousa,2005] que, por sua vez, requer o conhecimento prévio da vulnerabilidade sísmica do seu parque habitacional.Neste contexto, apresenta-se o panorama da construção existente em Portugal Continental, caracteriza-se e evolução das práticas construtivas ao longo do tempo, identificam-se os principais tipos de construção que subsistem e se praticam no Continente, descrevem-se, de forma sumária, os respetivos sistemas estruturais, mencionando as suas principais vulnerabilidades face à ação dos sismos (entendidas como as deficiências do seu desempenho sísmico), e tipificam-se as soluções construtivas mais correntes enquadrando-as nas tipologias identificadas no Censos 2001.

Nesta comunicação, de acordo com a metodologia desenvolvida noutro trabalho apresentado, estuda-se o problema do comportamento sísmico de edifícios assimétricos em planta recorrendo á explicitação de métodos de dimensionamento a partir de coeficientes de ductilidade locais, e de um critério de avaliação de desempenho da estrutura, baseado no conceito de probabilidade de colapso.Procedeu-se a uma exploração paramétrica de que resultam 504 estruturas assimétricas em planta. Procurou-se saber, para os cenários sismo próximo e afastado em Lisboa, quais as distribuições ótimas de resistência em termos da minimização da probabilidade de ruína.

Apresenta-se nesta comunicação um modelo analítico desenvolvido para estudar o comportamento dinâmico histerético, de estruturas reticuladas de betão armado preenchidas com paredes de alvenaria sob a ação de cargas horizontais repetidas e alternadas. A calibração dos parâmetros que definem o modelo analítico, foi efetuada de acordo com os resultados obtidos em ensaios laboratoriais, realizados no LNEC.A boa simulação analítica dos resultados experimentais obtida através do modelo desde que se adotem certos valores para os seus parâmetros definidores, permite concluir que o modelo analítico apresentado pode ser usado num âmbito mais generalizado da engenharia sísmica que é o da avaliação de segurança de edifícios sujeitos á ação de sismos intensos.

In this paper is presented an analytical model for the idealization of the hysteretic behaviour, under cyclic loadings, of reinforced concrete frames infilled with masonry panels. The calibration of the parameters which define the analytical model, was performed on the basics of the experimental results of three masonry infilled concrete frames models and one bare frame model tested at the LNEC.A fairly good fitting between analytical and experimental results were obtained for the selected values of the analytical model parameters. In consequence, this analytical model can be used in the more broader framework of Earthquake Engineering and structural reliability of buildings under large intensity earthquake.

Na presente comunicação referem-se os critérios para a idealização do comportamento sísmico de estruturas de edifícios assimétricos em planta através de osciladores não linear com três graus de liberdade.Estes critérios constituem a base de um modelo analítico desenvolvido com o objeto de se proceder à verificação da segurança, em relação à ação dos sismos, daquela classe de estruturas.

A group of five Portuguese experts on earthquake engineering visited the Los Angeles region after the 17 January 1994 Northridge earthquake. The observations mad during the field trip are briefly reports. Discussion is made on the behaviour of different types of structures, namely, masonry, wooden, reinforced concrete and steel structures, as well as special structural typologies such as precast parking lots, tilt-ups and bridges. The presentation is illustrated by means of a few cases, for which the causes of malfunctioning were anticipated.Mention is also made to the behaviour of lifelines, such as electricity, gas and water supply, sewage systems and telephones. The damage assessment is viewed under the light of the ground motion severity.A description of the organizational aspects and procedures adopted for the inspection, immediate reinforcement, recovery and reconstruction of the main buildings, bridges and other utilities are also referred.

Esta comunicação apresenta a conceção, o projeto, a instalação e o planeamento da utilização durante os dois primeiros anos do simulador sísmico triaxial que brevemente começará a funcionar no LNEC. Este simulador destina-se ao ensaio dinâmico até á rotura de grandes modelos de edifícios e ponte (até 60t). Este simulador realiza uma conceção inovadora, que se traduz essencialmente pela eliminação dos 3 graus de liberdade de rotação através de 3 sistemas mecânicos constituídos por uma barra de torção, duas manivelas e duas bielas.

The paper presents the results that permit the identification of optimal design methods for building structures in terms of a eccentricity and are calibrated for probability of failure, evaluated for critical scenarios of expected earthquake intensities.

Some fundamental aspects concerning the overall conception and mechanical design of the new LNEC seismic shaking table, which will have three translational degrees of freedom, are presented. Considerations are made regarding its adaptive control, pointing out the interactions between the behaviour of the mechanical and control systems as far the overall performance of the seismic shaking table is concerned. Lastly, some considerations are also presented on the special building that houses the shaking table.

In this paper we an analytical model to study the hysteretic behavior, under cyclic loading, of RC frames infilled with masonry panels.The calibration of the parameters which define the analytical model, was performed according to the experimental results obtained with three infilled RC frames models and one bare frames model tested at the LNEC.With a good selection of parametric values, the fairly good fitting between analytical an experimental results, allows to conclude that this model can be used in the more broader framework of Earthquake Engineering and structural reliability of buildings under large intensity earthquakes.

A stochastic model of earthquake ground motion, with non-stationary amplitude and frequency content, is presented. This model is quantified on the basis of the information available from seismic hazard studies and strong ground motion seismology with the purpose of generating artificial accelerograms to be used in nonlinear analysis and design of structures. The stochastic model is defined by a

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

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.

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

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.

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.

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.

Within the realm of natural hazards, geohazards are recognised as being particularly complex and often having the potential of triggering disasters. This complexity has led to increased political commitment and interest in engaging multi-stakeholder and citizens in disaster risk management. The AGEO project explored new forms to foster collaboration between civil society and authorities, using the rapidly developing field of citizen science and its innovative tool of citizens

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

Most of the Lisbon 18th century timber-framed masonry

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.

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

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This text reflects the first of the four lectures that the author has presented at Udine, Italy, at CISM

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

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.

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

O Laboratório Nacional de Engenharia Civil (LNEC) participa atualmente numa das sete Tarefas, doprojeto Europeu SHARE- Seismic Hazard Harmonization in Europe, mais precisamente na tarefa nº 2,intitulada Requisitos de engenharia e aplicações.O presente relatório de progresso descreve a participação do LNEC na sub-tarefa 2.5 - Cenários derisco sísmico para cidades Europeias selecionadas

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No presente relatório pretendem-se apresentar e definir alguns das linhasorientadoras para a simulação do comportamento dinâmico de fluidos no interior deAmortecedores de Líquido Sintonizado (TLDs), de acordo com o proposto na literatura.O problema da modelação do comportamento de fluidos no interior deAmortecedores de Líquido Sintonizado, à semelhança do que acontece parareservatórios, é complexo, sendo apresentados os principais modelos matemáticos emecânicos utilizados na actualidade.Assim serão descritos modelos de comportamento adoptados no casoparticular dos Amortecedores de Líquido Sintonizado (TLDs) e modelos simplificadosde sistemas de 1 (SDOF) ou mais graus (MDOF) de liberdade com com os referidosdispositivos de mitigação de acções dinâmicas acopladosO presente relatório servirá, à semelhança dos relatórios Sistemas passivos,activos, híbridos e semi-activos: Estado dos conhecimentos, Actividade experimentalna área dos sistemas passivos para a protecção sísmica de estruturas: Experiência doNESDE e Modelos de comportamento dinâmico para fluidos no interior dereservatórios como uma das linhas orientadoras para o desenvolvimento dos trabalhospropostos no âmbito do PIP 2009-2012 do NESDE-DE Protecção Sísmica deEstruturas: Reabilitação, reforço e sistemas inteligentes.

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This Report corresponds to Task 2 of the NEFOREEE (New Fields of Research inEarthquake Engineering Experimentation) Project and comprises the description of theLNEC triaxial seismic platform and a presentation of the experimental programdeveloped in the scope of this Project.It is presented a description of the facility and the 3D seismic table with graphicalsupport, drawings of sizing and photographs, as well as its control system. The maininstrumentation available at the NESDE laboratory and used for this test is alsoincluded in this report.The model tested is described as well as the sequence of tests and the correspondingobtained results. Finally a brief analysis of the results is made.

O presente relatório final do projecto USuET integra o trabalho já apresentado norelatório de progresso de Sousa & Afonso [2007], nomeadamente no que toca aoscapítulos 2, 3 e parte do capítulo 4 e, adicionalmente, descreve, em detalhe, asactividades desenvolvidas no projecto desde a data desse relatório (secção 4.2, ecapítulos 5 e 6). A parte da investigação conducente à actualização do Simulador deCenários Sísmicos para ambiente WebSIG, aplicado ao Arquipélago dos Açores, não seencontra descrita com o mesmo detalhe, neste relatório, pois enquadra-se na tese demestrado em Sistemas de Informação Geográfica de Afonso [2007], submetida àUniversidade Técnica de Lisboa. A versão definitiva desta tese, cuja discussão se prevêainda em 2008, será enviada oportunamente.

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This report describes the second phase activity of the Portuguese group in the Precast Structures EC8 research project. The Portuguese group is composed by Laboratório Nacional de Engenharia Civil (LNEC) and the Civibral, S.A. precast company. This phase follows the shaking table tests of a 2 stories structure of the same precast system, which is commercialized by Civibral. More information about these tests can be found in the repor.The goal of the work presented in this document is to assess the seismic behaviour of column-foundation and beam-column connections from the same precast system. To help achieve this goal, 4 column-foundation and 10 beam-column connections were tested using quasi-static, monotonic and cyclic tests, which were made imposing displacements to the specimens. The column-foundation connections (CFC) can be categorized as socket connections and the beam-column connections (BCC) as dry connections using only mechanical devices to transmit forces between elements. All the specimens were supplied and mounted by Civibral personal.

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.

Análise da forma das edificações nas ações do vento

As condicionantes arquitetónicas e de urbanização na ventilação natural

Caracterização do vento. Ações sobre estruturas. Ensaios em túnel de vento