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A avaliação da segurança sísmica de edifícios existentes de alvenaria tem como referência os procedimentos dispostos na NP EN 1998-3:2017 (Anexo C) e o respetivo Anexo Nacional, que estabelecem os requisitos de desempenho e os critérios de conformidade para edifícios existentes sujeitos a um determinado nível de ação sísmica. No seguimento das exigências regulamentares, e à luz da verificação da segurança à ação sísmica preconizada na norma, realizaram-se análises probabilísticas de vulnerabilidade sísmica e fiabilidade estrutural a um grande conjunto de edifícios de alvenaria representativos do parque habitacional, que conduziram ao desenvolvimento de métodos expeditos para a avaliação sísmica em alternativa à verificação pelo método de referência. Os métodos propostos permitem avaliar a resistência sísmica de edifícios de alvenaria com pavimentos rígidos, sem recurso a análises numéricas e recorrendo apenas a parâmetros geométricos (Método I) ou em conjunto com as propriedades mecânicas dos materiais (Método II).

The analysis and control of deformability of wall coating mortars contributes to minimize crack development and propagation, one of the most common anomalies in building facades. Many of these cracks appear due to internal stresses in the coating mortar, because of imposed deformations or of imposed restrictions by the substrate. These deformability studies should include one or more experimental methods to determine the modulus of elasticity (E) of the coating mortars in question. There are two approaches to experimentally determine E for mortar specimens: static and dynamic experimental methodologies. For civil engineering applications, the results obtained from static methodologies are more adequate than those obtained with dynamic methodologies. However, since static E results are scarce due to a lack of an established static methodology for mortars, mainly due to their lower mechanical resistance, friable behaviour and higher frailty when compared to concrete, engineers are led to use the established dynamic methodologies. This paper proposes an experimental methodology to determine the static E for moulded mortars specimens. The methodology was adapted from the standard procedure used for concrete specimens, to accommodate the specific characteristics of mortar specimens, namely: provide reliable displacement and applied load data; solve issue related to specific mechanical characteristics of mortar specimens, such as low strength and friable behaviour. This methodology was applied to standard moulded mortar specimens made from multiple mineral binders (cement, hydraulic lime and air lime). In order to validate it, the obtained results were compared with two, well-established, dynamic experimental methodologies (Resonance Frequency and Ultrasonic methodologies) as well as with reference values from relevant bibliography. Using the previous data, this paper also includes a preliminary analysis on the ratios between static and dynamic E values for the studied mortars, representing another objective of this study.

This paper addresses the planar measurement problem in the destructive mechanical testing of masonry specimens, describing the proposed optical measurement solution. The adopted affine geometrical camera model is described as well as its experimental implementation using a digital camera and a measurement referential traceable to the International System of Units (SI). Experimental results from non-destructive tests are presented and discussed, including measurements obtained from the use of classical contact instrumentation. Measurement estimates and uncertainties related to the quantified mechanical properties are also shown.

As construções antigas fazem parte do tecido histórico das cidades, pelo que é importante proceder a intervenções de reabilitação eficientes, mas não destruidoras da sua identidade e valor cultural intrínseco. A utilização de rebocos armados apresenta-se como uma solução simples e eficaz no reforço sísmico deste tipo de construções, nos casos em que não é possível ou exigível a preservação dos revestimentos de paredes. Neste artigo, são analisadas várias composições de rebocos armados, constituídos por ligantes à base de cal aérea, cal hidráulica ou cimento, com um traço usual e com armaduras constituídas por redes metálicas, redes de fibra de vidro e uma rede de fibra natural. É analisada a capacidade resistente à tração dessesrevestimentos armados, assim como aspetos que podem influenciar a compatibilidade com os materiais existentes, apresentando-se as principais vantagens e desvantagens dos vários tipos de revestimentos.

Os edifícios tipo

As construções antigas fazem parte do tecido histórico das cidades, pelo que é importante proceder a intervenções de reabilitação eficientes, mas não destruidoras da sua identidade e valor cultural intrínseco. No contexto do reforço sísmico, a utilização de rebocos armados apresenta-se como uma solução simples e pouco intrusiva. Os rebocos armados em paredes conferem um aumento da resistência e da ductilidade ao corte (no plano) e da ductilidade à flexão (fora do plano), um aumento da resistência superficial e permitem ainda um melhor controlo da fendilhação.Neste artigo será apresentada a caracterização experimental dos materiais constituintes das alvenarias (argamassas de assentamento, argamassas de revestimento e tijolos), e os resultados obtidos em ensaios de compressão diagonal de pequenos provetes de alvenaria, com e sem a aplicação de rebocos armados.

This paper describes a shake table test on a one-storey full-scale unreinforced masonry structure, which complements an earlier testing of a two-storey structure with similar characteristics. The building specimen was meant to represent the upper floors of the end-unit of a terraced house, built with cavity walls and without any particular seismic design or detailing. In these specimens, the masonry walls were composed of two leaves: a load-bearing inner one made of calcium silicate bricks sustaining a reinforced concrete floor and an external leaf made of clay-bricks connected to the inner leaf by means of metallic ties. A pitched timber roof was supported by two triangular gable walls. Floor acceleration response histories of the previously tested two-storey specimen were used as input motions. An incremental dynamic test, with vertical and horizontal inputs, was carried out up to the explicit collapse of some bearing elements of the structure. In particular, a two-way bending out-of-plane collapse of a load-bearing wall was observed and described.

Sheds roof is a natural ventilation strategy that presents roof openings working as air collectors or extractors. A detailed review of the literature indicates a lack of research analyzing the impact of different sheds roof shapes and roof configurations on natural ventilation potential. his paper aims to evaluate the impact of changes in distance and alignment between wind catcher and leeward sheds roof. The methodology was Computational Fluid Dynamics (FCD) simulation. tests were performed in a atmospheric boundary layer wind tunnel on a 1:15 scale model to evaluate the accuracy of CFD simulations in different design configurations of sheds roof. The analysis showed that CFD simulations are generaly in good agreement with the wind tunnel tests. The difference between the most o the monitored points in the two tools used had errors below 10%. besides this, the results show that changes in alignment of the sheds and increasing distance between them decrease and increase the internal airflow to the leeward and windward sheds of the roof, respectively. In the first case it is due to the reduction in the sheds openings area. In the second these changes turn the sheds more effective in the air capture.

Apresenta-se neste artigo um estudo de análise da segurança das pontes Criz II e de São João de Areias, na albufeira da barragem da Aguieira, em Portugal, durante a execução de novas fundações, no âmbito das empreitadas de reabilitação, na proximidade dos pilares afetados por reações expansivas do betão no seu embasamento. A ação dinâmica induzida pela perfuração de maciços rochosos foi modelada como uma ação periódica composta por um momento torsor aplicado na fundação de cada pilar isolado combinado com três forças ortogonais representando a força imposta pela caroteadora e os desequilíbrios das tensões de corte por rotação.Através da análise dinâmica linear das estruturas completas e de análises não lineares estáticas e dinâmicas dos pilares, foram estabelecidas as condicionantes às vibrações induzidas pelas máquinas caroteadoras, nomeadamente em termos de limites máximos da resposta em velocidade no topo dos embasamentos, edefinidas as condições de monitorização da estrutura durante a obra. Estas especificações foram elaboradas em estreita colaboração com técnicos da Infraestruturas de Portugal, I.P., e incluídas nas Cláusulas Técnicas Especiais para o lançamento da empreitada.

Understanding the out

Earthquake scenarios are used in different activity domains like: civil protection disaster preparedness, computing overall seismic losses for a portfolio, or evaluating time histories and ground motion duration to be used in seismic design. However, the choice of an earthquake scenario is often based on deterministic arbitrary assumptions, like the region worst historical event reported. The purpose of this work is to overcome the disadvantages of a deterministic approach, in what concerns the choice of earthquake scenarios in Portugal. For each of the 278 Portuguese counties, a scenario ground motion based on a probabilistic seismic hazard disaggregation analysis is evaluated. Portuguese probabilistic seismic hazard analysis is reviewed in order to perform its disaggregation. Probabilistic seismic hazard was disaggregated considering different spaces of random variables. Bivariate conditional hazard distributions in X-Y (seismic source latitude and longitude) are analyzed, as well as multivariate conditional hazard distributions in M-R-

This paper describes and analyses the results of the seismic tests preformed at LNEC in a RC precast structure which is representative of a Portuguese system. This type of precast construction is used mainly for industrial buildings and was designed and constructed by a precast company with their common practice. The precast system can be considered as jointed with dry connections of limited ductility. A scaled 1/3 specimen was tested on LNEC

With the purpose of assessing the seismic behaviour of a reinforced concrete building structure non-seismically designed, an experimental study was carried out at the LNEC/Lisbon shake table, within the framework of the European project SPEAR. The tested structure was a simplification of a 3-storey building, irregular in plan, representative of older construction in southern Europe, without engineered earthquake resistance. It was designed for gravity loads alone, using the concrete design code used in Greece between 1954 and 1995, with construction practice and materials commonly used in southern Europe in the early 70

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

The paper presents an experimental program on a 5 storey structural wall physical model performed in LNEC 3D shaking table, in Lisbon, within the Project ECOLEADER-LIS. The characteristics of the reduced model and the test set-up are described, as well as the analysis of the main experimental results. Furthermore the results of numerical simulations are discussed. These tests had the main purpose of studying and evaluating the seismic resistance of thin lightly reinforced structural walls representative of the Central Europe practice. Particular issues have been adressed: (a) To investigate the influence of simultaneous 3D loading conditions. (b) To study walls with T (H) cross-sections. (c) To investigate the free edge of a T (H) shaped walls in compression and different trypes of confinement. (d) To investigate the behaviour of coupled walls and the behaviour of diagonally reinforced coupling beams in thin walls. (e) To calibrate and further develop numerical models. Inelastic dynamic analysis was also performed using Multiple-Vertical-Line-Element-Model (MVLEM), which was extended into 3D and implemented into OpenSees. This macro model proved the ability to simulate and predict the global behavior of the wall as well as the behavior of confined boundary areas and local extensions of longitudinal reinforcement. Considerable overstrength was observed in the wall with minimum reinforcement. However, its deformation capacity was limited to less than 1% of the height. Relatively thick slab enhanced the strength of thin coupling beams considerably. Consequently, they did not perform as expected in capacity design and high axial forces as well as shear failure were induced into the wall piers. The EC8 confining reinforcement proved to be efficient. Simpler details (i.e. U-shaped stirrups) might be acceptable for low walls (5-storey) and/or in the case of low seismic intensity. Sequence of loading and pre-cracking influenced the response considerably. The influence of bi-axial loading was relatively low.

In the process of preservation of ancient masonry structures, damage evaluation and monitoring procedures are particularly attractive, due to the modern context of minimum repair and observational methods, with iterative and step-by-step approaches. High-priority research issues related to damage assessment and monitoring are global non-contact inspection techniques, sensor technology, data management, diagnostics (decision making and simulation), dynamic (modal) analysis, self-diagnosing / self-healing materials, and prediction of early degradation. On these concerns, the present paper aims to assess damage in masonry structures at an early stage. Replicates of historical constructions were built in virgin state. Afterwards, progressive damage was applied and modal identification analysis was performed at each damage stage, aiming at finding adequate correspondence between dynamic behavior and internal crack growth. Accelerations and dynamic strains were recorded in many points of the replicates. Comparisons between different techniques based on vibrations measurements are made to evaluate different damage identification methods.

This work uses a non-stationary stochastic seismological model, based on random vibration theory, for calculating response spectra and synthesizing strong ground motion acceleration records for Portugal Mainland. The validation of the method and comparison with strong ground motion records for Portugal are entirely carried out in terms of 5% damped pseudo absolute response spectra for acceleration. The calibrated model is used to simulate ground motion acceleration for the 1755 Lisbon earthquake. Five potential source rupture models that have been recently proposed by several authors for the 1755 Lisbon earthquake are tested: two analytical models based on hydrodynamic studies; two models based on seismic surveys and on from a recent suggestion based on induced stress changes.For all models, peak ground acceleration maps are compared with iso-intensities map of the earthquake in order to test the ability of the source models for estimating the intensities of the earthquake. The peak ground motion is calculated for different unknown parameters like the rupture velocity, the slip distribution and the nucleation point. The fault parameters like dimension, dip and strike are the ones proposed by the authors of the different analysed source models

This paper presents a dynamic identification analysis of a masonry construction, built to be tested in

In the framework of the ongoing European project

En este trabajo se confirma experimentalmente una nueva formulación del problema de los bloques rígidos sometidos a vibraciones externas. Un estudio sistemático de las respuestas del sistema permite determinar los valores de los parámetros relevantes. La nueva formulación hace más sencilla la implementación de técnicas computacionales para el problema da varios tipos de mecanismos acoplados. En las respuestas analizadas, tanto para régimen libre como forzado, se ha observado un buen acuerdo entre teoría y experimento.

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.

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 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.

A avaliação da segurança sísmica de edifícios existentes tem como quadro de referência o Eurocódigo 8

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.

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).

This document reports the outcomes of the research project

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.

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.

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.

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.

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.

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