Publications

In order to promote an effective approach to the prevention of and preparedness for disasters, the countries participating in the Union Civil Protection Mechanism (UCPM) shall develop risk assessments, risk management capability assessments and disaster risk management planning at national or appropriate sub-national level. The European Commission is providing scientific support to the countries participating in the UCPM, publishing updated guidelines to facilitate the development of their National Risk Assessments (NRAs). Earthquake is among the most common hazards considered in NRAs prepared by the countries participating in the UCPM. Indeed, in 2018 NRAs, more than 20 countries performed risk assessment for earthquakes, and some considered cross-border and cascading effects, such as tsunami, landslides, disruption of infrastructure and industrial accidents. This paper surveys and summarises the current state of research that can be utilized for national seismic risk assessment. It aims to facilitate the development of consistentNRAs with respect to earthquakes and ensure their utility in seismic risk management planning. It also aims to support the use of the new reporting guidelines on disaster risk management among countries participating in the UCPM. The seismic risk assessment process is described as outlined in ISO 31000: 2018. A wealth of hazard, exposure, vulnerability and damage-to-loss models, methodologies and tools are presented to serve the purpose of conducting national seismic risk assessment. References to relevant European research projects, good practices, and software to support the assessment are also provided.

The metropolitan area of Lisbon is the region of Portugal with the highest seismic risk, given the coexistence of moderate-to-high hazard with highpopulation density and building stock exposure. The present work addresses the seismic risk assessment of pre-code masonry buildings in this region, accounting various typological classes and conservation states in order to evaluate the consequences in terms of economic losses. The analyses are conducted through a seismic probabilistic approach, considering the sitespecific ground motion through a non-stationary stochastic method. The results can serve as a useful guide for decision-making in developing regional seismic risk mitigation strategies.

Given the 516 Arouca pedestrian suspension bridge

Azores Islands are seismically active due to the tectonic structure of the region. Since the 15th century, they have been periodically shaken by approximately 33 moderate to strong earthquakes, with the most recent one in 1998 (Mw = 6.2). Nonetheless, due to insufficient instrumental seismic data, the region lacks a uniform database of past real records. Ground motion simulation techniques provide alternative region-specific time series of prospective events for locations with limited seismic networks or regions with a seismic gap of catastrophic earthquake events. This research establishes a local ground motion model (GMM) for the Azores plateau (Portugal) by simulating region-specific records for constructing a homogeneous dataset. Simulations are accomplished in bedrock using the stochastic finite-fault approach by employing validated input-model parameters. The simulation results undergo validation against the 1998 Faial event and comparison with empirical models for volcanic and Pan-European datasets. A probabilistic numerical technique, namely the Monte-Carlo simulation, is employed to estimate the outcome of uncertainty associated with these parameters. The results of the simulations are post-processed to predict the peak ground motion parameters in addition to spectral ordinates. This study uses XGBoost to circumvent the difficulties inherent to linear regression-based models in establishing the form of equations and coefficients. The input parameters for prediction are moment magnitude (Mw), Joyner and Boore distance (RJB), and focal depth (FD). The quantification of GMM uncertainty is accomplished by analyzing the residuals, providing insight into inter- and intra-event uncertainties. The outcomes demonstrate the effectiveness of the suggested model in simulating physical phenomena.

The characteristic values of temperature corresponding to the maximum and minimum shade air temperature with an annual probability of being exceeded 0.02, used in the European construction standard for thermal actions (EN 1991-1-5:2003), are usually assessed at a country level and included in the National Annexes to that Eurocode part.The paper aims to support national authorities on elaborating maps for thermal actions using publicly available datasets, consistent at a European level, and harmonised modelling approaches. In addition, these datasets are continuously updated, reflecting the current climate and capturing potential global warming variations.The work investigates how updates in data and modelling could affect the characteristic values currentlyadopted in the Italian National Annexes to the Eurocodes. The main results show that: (i) the currently adoptednumber and locations of the weather stations result fairly representative of the patterns detected by exploitingadditional datasets; ii) the statistical method plays an essential role in the assessment of characteristic values, i.e., the method adopted in the current Italian standard evaluates more conservative characteristic values of maximum temperature than Gumbel or Generalized Extreme Value distributions, but could err on the unsafe side for minimum ones; (iii) both E-OBS and ERA5-Land datasets represent two optimal products to be used as a common source of temperature values at European scale; (iv) moving towards an updated period for temperature data results on an increase of characteristic values of maximum temperature and limited variations in spatial extent and magnitude of characteristic values of minimum ones.

The present work analyses the wind load effects on the 516 Arouca bridge, the world's longest pedestrian suspension bridge in 2020. Computational fluid dynamics (CFD) was used to model a range of wind incidence angles between -8

The safety and resilience of school buildings against natural disasters is of paramount importance since schools represent a reference point for communities. Such significance is not only related to the direct consequences of collapse on a vulnerable part of the population, but also due to the importance of schools in the post-disaster recovery. This work is focused on the risk and resilience assessment of school buildings in Lisbon (Portugal) under seismic events. The results of this study, in which a subset of 32 schools are analyzed, are used to define a prioritization strategy to mitigate the seismic risk of the Lisbon City Council school building portfolio and to assess the overall resilience of the school network. Numerical modeling of the school buildings is performed in order to estimate losses in terms of the built-up area of the schools and recovery times associated with different seismic scenarios, which are probabilistically defined specifically for the sites of the buildings, accounting for the local soil conditions and associated amplification effects. Based on the obtained risk estimates, which are compared to reference values established on international guidelines and specialized literature, the Lisbon City Council and LNEC jointly defined a short- and medium-term risk mitigation plan, starting with a detailed inspection and assessment of the most vulnerable school buildings and continuing to the implementation of retrofitting measures.

Probabilistic seismic hazard assessment (PSHA), despite its deep criticism, is still the most common tool used to decide on the acceptable seismic risk and corresponding mitigation measures. We propose two consistency tests to address the variability of earthquake generation models found in PSHA studies: (i) one rule-of-thumb test where the seismic moment release from the model is converted to an average slip on a typical fault and compared with known plate kinematics or GNSS deformation field and (ii) a test where using a neotectonic model the computed deformation is converted into seismic moment release and to a synthetic earthquake catalogue. We apply these tests to W and SW Iberia slowly deforming region, where two earthquake source areas are investigated: (1) the Lower Tagus Valley, one of the largest seismic risk zones of Portugal; and (2) the offshore SW Iberia area, considered to be the source for the 1 November 1755 event (M

Procuram-se sintetizar neste artigo os principais aspetos relacionados com a avaliação e a reabilitação sísmica de edifícios existentes de alvenaria, compatibilizando a NP EN 1998-3:2017 com os respetivosAnexo C, específico para edifícios de alvenaria, e Anexo Nacional, específico para Portugal.A avaliação sísmica é um procedimento quantitativo através do qual se verifica se um edifício existente, danificado ou não, satisfaz os requisitos de desempenho, definidos por uma combinação de um estado limite com um nível de ação sísmica, através de critérios de conformidade. Neste procedimento estão envolvidos a definição da ação sísmica, a modelação da estrutura, os métodos de análise para determinação dos efeitos das ações e as verificações de segurança. São abordados os métodos de análise, dois lineares e dois nãolineares, aplicáveis a edifícios existentes de alvenaria, bem como as recomendações específicas do Anexo C e as informações complementares do Anexo Nacional.

The response of three full-scale unreinforced masonry buildings, without specific seismic detailing, as observed in shake table testing at LNEC for a seismic action representative of induced seismicity, is presented. The first building specimen simulated the upper floor and roof of the end-unit of a two-storey terraced house, built with unreinforced cavity walls, a reinforced concrete slab and a pitched timber roof. The second specimen was a replica of the roof of the first building. The third specimen represented instead a one-story detached pre-1940

Esta comunicação refere-se aos ensaios de caracterização dinâmica realizados pelo LNEC após a conclusão das obras de alargamento do tabuleiro rodoviário e de colocação do tabuleiro ferroviário na ponte 25 de Abril. Estes ensaios consistiram na medição de acelerações na estrutura resultantes da ação do vento e do tráfego rodoviário, tendo sido efetuados com o objetivo de avaliar experimentalmente as características dinâmicas globais da ponte. Descrevem-se os equipamentos e os procedimentos adotados nos ensaios, bem como os métodos utilizados na análise dos registos obtidos. Comparam-se também as características dinâmicas avaliadas nos ensaios com as calculadas com um modelo de elementos finitos.

This paper presents part of the work developed for the seismic behavior study of an ancient structure, over 400 years old. The church structure was numerically modeled via the finite element method, using a three dimensional model with parameters calibrated by experimental testing. In situ and laboratory tests on extracted samples were performed, and dynamic tests were carried out for modal identification and structural stiffness calibration. The seismic analysis was performed in two calculation phases, under the action of artificially generated accelerograms representative of the local seismicity. Results of linear elastic dynamic calculations allowed the global behavior to be analyzed and provided the input for more detailed local analyses of structural parts where the non-linear behavior was considered. Finally, the seismic vulnerability of the structure is briefly addressed and discussed.

Nesta comunicação descrevem-se a apresentam-se os resultados dos ensaios de caracterização dinâmica da estrutura de ampliação do aeroporto de Stª Catarina na ilha da Madeira. Estes ensaios integraram-se nos ensaios de receção efetuados pelo LNEC após a conclusão das obras de construção da estrutura, antes do início da sua utilização para o tráfego de aviões. Os ensaios dinâmicos consistiram na medição de acelerações na estrutura induzidas pelo tráfego de camiões carregados, e pela libertação repentina de um peso de 608 kN suspenso a meio vão de dois dos painéis de laje da estrutura. Descrevem-se os equipamentos e as técnicas adotadas nos ensaios, bem como os métodos utilizados na análise dos registos obtidos.

In order to assess hazard seismic scenarios for a region selected sites, seismic deaggregation was evaluated applying a mixed model that uses (i) gross source zones to compute b_values and maximum magnitudes and (ii) geographically uniform bins to obtain seismic rates. Results are presented in terms of magnitude and geographical coordinates for the parishes of Lisbon County and surrounding areas. Once obtained the most likely scenarios that can affect the metropolitan region of Lisbon, seismic risk scenario was assessed weighting those scenarios with the geographic distribution of elements at risk in the region. The final risk scenario was the one that conducted to the higher total risk for the region in each considered return period.

With the aim of evaluating the seismic vulnerability of residential buildings in Portugal, the classification of the Portuguese housing stock was possible on the basis of a National database published in 1991. The study herein reported, included in a National Project concerning the seismic risk mitigation in Portugal, deals with the analysis of the database that resulted in the establishment of the most current building types in seismic prone regions with higher urban concentrations. The paper presents a summary of the analysis of the statistics of the stock and its geographic distribution, and includes the classification of residential buildings into typological classes, which vulnerability is characterised through a HAZUS99-based methodology.

Nesta comunicação descreve-se o trabalho desenvolvido no estudo do comportamento sísmico da Igreja do Mosteiro da Serra do Pilar. A partir da modelação numérica tridimensional da igreja e da quantificação de parâmetros mecânicos e dinâmicos da estrutura, a análise sísmica foi realizada em duas fases de cálculo. Procedeu-se a um primeiro cálculo linear global da estrutura, seguido de um segundo cálculo da subestrutura dos arcos e colunas de apoio onde foi ativado o comportamento não-linear das juntas entre blocos e analisado o efeito resultante da aplicação de intensidades sísmicas crescentes.

No presente trabalho apresenta-se uma primeira reavaliação da casualidade sísmica das ilhas do Grupo Central do Arquipélago dos Açores, com o objetivo de se estabelecer um zonamento atualizado e mais detalhado para o Arquipélago.Este estudo foi efetuado com base na compilação de catálogos sísmicos históricos e instrumentais da região dos Açores, e num modelo de 9 grandes zonas de geração, utilizando duas metodologias: (i) a clássica e (ii) uma baseada na distribuição espacial da sismicidade. A geologia superficial das diferentes zonas urbanas foi classificada em três categorias (solo duro, solo intermédio e solo brando), de forma a ser contemplada nas leis de atenuação espectral publicadas na literatura.Comparam-se as duas metodologias e apresentam-se curvas de casualidade sísmica para as sedes de concelho das ilhas do Grupo Central e mapas de casualidade sísmica para um período de exposição de 50 anos e uma probabilidade de excedência de 10%.

Com o objetivo de estudar a vulnerabilidade sísmica do parque habitacional de Portugal Continental, foi efetuado o seu levantamento com base no III Recenseamento Geral da Habitação e no XIII Recenseamento Geral da População levados a cabo pelo Instituto Nacional de Estatística em 1991. A análise do inventário de existências permitiu estabelecer a tipificação do parque habitacional português e classificar as tipologias construtivas mais correntes nas zonas de maior sismicidade e maior concentração urbana. Este estudo está incluído no âmbito do projeto

Um dos objetivos do projeto

Large seismic source zones and the modelling of epicentral location by the uniform probability distribution are two options that contribute to smoothed results in probabilistic seismic hazard studies. In order to obtain less smoothed results that reflect the geographical underlying seismic activity it was adopted an empirical distribution, based on the seismic catalogue, to model the random variable epicentral distance. This option avoid the outline of seismic sources in regions where seismogenic structures are poorly known and are the first step to estimate hazard de-aggregation at a site. The methodology was applied de-aggregating seismic hazard for all counties of the Central Group of Azores Archipelago. The relative contribution to the hazard of mean and modal values of magnitude and distance is tabulated for those counties aiming to identify the dominating events to the site. A de-aggregation plot for the county with the severest hazard is also presented, for different spectral periods.

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

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This report addresses the National Laboratory for Civil Engineering (LNEC) participation in Subproject 10 Earthquake disaster scenario predictions and loss modelling for urban areas. More precisely this report was developed in order to accomplish the 24 months LESSLOSS deliverable nº 85, which achieves loss estimates for the Metropolitan Area of Lisbon (MAL), for pre-defined scenarios earthquake. These loss estimations represent the reference situation to be compared with revised loss estimates after implementing mitigation actions with the ultimate goal of being established, in the next deliverable, the

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The present report describes the construction of a model in limestone masonry for the user Group 3 oh the ECOLEADER Project, led by IRIDEX Construction Group, and the first phase of the experimental program developed in LNEC. The description of the construction, a photographic report and the results obtained on the characteristics tests made on the mortars used in the construction are presented.The construction was carried out by contractor José dos Santos Paixão on the basics of model details and materials specifications proposed by the User group 3, being NESDE/LNEC responsible for the guidance and supervision of the works.

This report describes the first phase activity of the Portuguese group in the Precast Structures EC8 research projet. The Portuguese group is composed by Laboratório Nacional de Engenharia Civil (LNEC) and the Civibral, S.A. Precast Company.In this phase, seismic test were made in the LNEC

The present report addresses the first twelve months of LNEC participation in LESSLOSS

The dynamics of rigid bodies was studies by long time, because this phenomenon is important in the seismic security of some types of structures. However, there are few experimental studies. This job shows the experimental test carried out at the Laboratório Nacional de Engenharia Civil (LNEC) of Portugal. Four blue granites stones were tested, each one with different geometrical characteristics, under harmonic and random motions.A numerical simulation was carried out with the Discrete Element Method (DEM). This method has shown to be a good tool in the study of the dynamics of rigid bodies. It was proposed a new methodology to find the parameters of the DEM by using the parameters of classical theory.

The project LESSLOSS

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