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Despite the fact that in recent years Portugal has not seen the occurrence of high-magnitude earthquakes, it remains threatened by these events due to its geographic location. Since the 1960s, reinforced concrete has been the most used material for new constructions, however the historic urban centers are dominated by old unreinforced masonry (URM) buildings which techniques and construction materials have evolved since the Great Lisbon earthquake that occurred in 1755 with a magnitude around 8.5. Given the presence of these buildings in areas of significant seismicity, a comprehensive research is needed to assess the seismic risk and define mitigation policies. This kind of studies are often supported by empirical methods and based on expert judgment due to the high variability of the building stock and lack of information. The main purpose of this work is: i) to provide analytical fragility curves, supported by nonlinear static analysis, for the entire population of old masonry buildings, built before the introduction of the first design code for building safety against earthquakes (RSSCS) in 1958; ii) define vulnerability curves to be used by the technical community for seismic risk assessment of pre code URM buildings. The characterization of the building stock geometry and material properties is based on the previous information collected, which was useful to define representative archetypes and typologies.

The seismic performance of buildings has received special attention due to the interest in the built heritage conservation and protection of human life. The historic urban centers are dominated by old unreinforced masonry (URM) buildings, which techniques and construction materials have evolved during centuries. Given the presence of these buildings in areas of significant seismicity, extensive research is needed to assess the seismic risk and define mitigation policies. This kind of studies is often supported by empirical methods and based on expert judgment due to the high variability of the building stock and lack of information. The main purpose of this work is to provide analytical fragility curves for representative masonry buildings in Portugal, built before the introduction of the first design code for building safety against earthquakes (RSSCS) in 1958. Thus, the fragility curves derived can characterize the capacity of the Portuguese building stock considering the randomness in the material properties and the variability in the geometry.

The seismic safety assessment of 3D complex structural elements of historic buildings, such as cross vaults, is a challenge and experimental tests can provide relevant data for this purpose. This paper presents the results of two experimental campaigns in a reduced scale 3D printed vault characterized by asymmetric boundary conditions. The specimen adopted the typical geometry of groin vault (without ribs) and was made of polymeric bricks placed in an orthogonal bond disposition. The seismic behaviour of the vault was studied through quasi-static and dynamic tests using the shake table. In particular, an incremental dynamic analysis up to the collapse of the vault was carried out. The results obtained experimentally were analysed in terms of damage, collapse mechanisms, displacements, in-plane distortion and response spectrum-based analysis.

Post-earthquake damage reports have continuously highlighted the significant vulnerability of nonstructural elements to seismic events. Nonstructural damage has severe impact in the building recovery, increasing the socioeconomic losses even for low intensity events. In the last few years, research efforts have focused on the development of innovative nonstructural solutions, to be combined with damage-resistant structural skeletons in order to obtain an overall highperformance building. As part of a European Union (EU)-funded project, the effectiveness of such integrated skeleton&envelope low-damage system in reducing the earthquake related losses was investigated. Tridimensional shake table tests on a 1:2 scaled timber-concrete low-damage structural skeleton, “dressed” by different innovative nonstructural elements (glass/concrete facades, gypsum/ masonry partitions), were performed at the National Laboratory for Civil Engineering (LNEC) in Lisbon, Portugal. The shake table testswere carried out at increasing seismic intensities to investigate the structural and nonstructural performance up to a higher-than Collapse Prevention Limit State according to the Italian Code (975 years return period). This paper focuses on the dynamic behavior of nonstructural elements with detailed discussion on construction detailing, seismic demand and performance of the innovative solutions. The high performance of nonstructural elements proved the potential of the details introduced in the partitions/facades. Minimal or no damage was observed up to the end of the overall testing sequence, which reached moderate-to-high interstory drift ratios (more than 1.00%) - typically expected to cause severe damage to traditional nonstructural partitions/infills/facades.

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.

After the large destruction of Lisbon due to the 1755 earthquake, the city had to be completely rebuilt. The innovative “Pombalino” buildings, named after the Prime Minister Marquis of Pombal, were then developed. This type of building is characterized by its structural interior “frontal” walls in elevated floors, composed of a timber frame with vertical and horizontal elements, braced with diagonals and masonry infill. The research presented in this paper aims at assessing the seismic behavior of the “Pombalino” buildings and proposes a strengthening technique by reinforcing the timber framed “frontal” walls. The experimental program was based on extensive dynamic testing on prototypes representative of typical “frontal” walls. The results of the dynamic tests carried out in the LNEC 3D shaking table are presented regarding the two types of tests performed: (a) seismic tests, in which the seismic action was applied with increasing amplitude in the in-plane direction; (b) dynamic identification tests, performed before the first and after each increasing amplitude seismic test, aiming at evaluating the evolution of the models’ mechanical properties with increasing seismic amplitude tests. A comparison of the performance of the non-strengthened and strengthened tested prototypes is also presented.

The paper addresses the seismic vulnerability assessment of a multi-span footbridge, prone to span unseating due to shorter seat lengths. The structure is representative of a series of pedestrian c...

This paper describes the development process and initial tests performed with a new energy dissipation damper based on Shape Memory Alloy (SMA) wires. The aim of this study was to develop a new iteration of this type of devices, and eventually develop a methodology to properly design them for any type of application. The underlying concept of our device is the use of a double counteracting system of pre-strained SMA wire sections as the dissipating component. By using pre-strained wires, this design focuses on maximizing energy dissipation, partially relinquishing the re-centering capabilities of the device. The experimental part was performed on a downscaled prototype based on this design methodology. The goal of this study was to validate the basic mechanical concepts. The device was subjected to a considerable number of load cycling tests, in order to better characterize the SMA wire behavior when used in this arrangement and to improve our understanding of their influence on the device's capabilities.

This article presents the results of the LNEC-3D shaking table tests on two mock-ups, Brick House and Stone House, carried out in the scope of the workshop Methods and challenges on the out-of-plane assessment of existing masonry buildings. The mock-ups have a U shape with one facade wall and two orthogonal sidewalls. The facade has a central opening and a gable on top, whereas the two sidewalls, acting as abutments, are either blind or have a window. A unidirectional seismic action, in the perpendicular direction to main wall, was applied. Out-of-plane behavior of the facade was found, even if the response was clearly influenced by the presence of the window in one of the sidewalls, which led to significant torsion of the structure. The detailed description of the two tests and the conclusions are presented. The response of the mock-ups was evaluated based on the displacements, damage, and collapse mechanisms developed as function of an increasing intensity earthquake testing protocol, in which a pre-processed strong ground motion component of the Christchurch (New Zealand) earthquake (February 21, 2011) was used., info:eu-repo/semantics/publishedVersion

Summary Several factors influence the behaviour of infilled frames, which have been a subject of research in the past with moderate success. The new generation of European design standards imposes the need to prevent brittle collapse of the infills and makes the structural engineer accountable for this requirement, yet it fails to provide sufficient information for masonry infills design. Therefore, the present work aims at understanding the seismic behaviour of masonry infill walls within reinforced concrete frames, using both unreinforced and reinforced solutions (bed joint reinforcement and reinforced plaster). For this purpose, three reinforced concrete buildings with different infill solutions were constructed at a scale of 1:1.5, all with the same geometry, and were tested on the shaking table of the National Laboratory for Civil Engineering, Portugal. All solutions performed adequately for the design earthquake, with no visible damage. Still, the experimental tests show that the double-leaf-unreinforced infill walls underperformed during a large earthquake, collapsing out of plane by rotating as rigid bodies with multiple configurations. Also the reinforced concrete buildings collapsed, because of the adverse interaction with the infill walls. The infill walls with bed joint reinforcement and reinforced plaster did not collapse out of plane, because of their connection to the concrete frame, which is an essential requirement. Copyright © 2016 John Wiley & Sons, Ltd.

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.

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):107–137, 2012a; Becker JS, Paton D, Johnston DM, Ronan KR. J Civil Eng Archit 6(6):673–681, 2012b). Becker et al. (in ibid) conceive such a process composed of a series of stages: knowledge and awareness, thinking and talking, understanding the consequences, developing skills. The above-mentioned pilot experience of risk communication was designed in order to trigger the cognitive process underlying behavioral change. Lisbon is a dormant society as far as earthquake risk is concerned. Given this, risk communication was firstly designed to generate awareness and knowledge among target-groups.

In the scope of the KnowRISK research project a set of tests were carried out on the LNEC-3D shake table in order to assess the seismic performance of several non-structural elements and building contents. The aim was to create a room that was as realistic as possible, not only in terms of spatial arrangement but also in terms of furniture and decorative objects. This would allow the presence of daily-life objects and furniture that can represent hazard inside regular homes during an earthquake. Damages were observed with increasing intensity seismic motions. In some of the tests different non-structural protective measures were implemented in order to observe how they mitigate the damage. Videos of the entire set-up were recorded during the tests, for the KnowRISK interventions, and accelerations were measured in a wardrobe and a bookcase. This allowed to obtain qualitative as well as quantitative data about the objects’ seismic performance.

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.

The energy dissipation capacity of the NiTi alloy was evaluated as part of a series of shake table tests. A superelastic damper was developed to take advantage of the hysteretic energy dissipation associated with this type of shape memory alloy. Each device was tested at different intensity levels. A vertical steel cantilever with 600 kg mass on top was subjected to a series of ground motions with different spectral characteristics. The dampers were placed as part of a tie system, restraining the horizontal movement of the top mass. The devices showed stable hysteretic behavior allowing for energy dissipation.

Most of the Lisbon 18th century timber-framed masonry “Pombalino” buildings currently need seismic rehabilitation due to: (i) natural degradation with aging; (ii) need for adaptation to new serviceability requirements, generally involving higher loads and consequent structural changes; (iii) former interventions with elimination or damage of structural elements, affecting seismic resistance and (iv) noncompliance with the present seismic codes. The research presented in this paper aimed at experimentally evaluating the seismic vulnerability of the “Pombalino” buildings and at proposing a strengthening technique to reduce it by reinforcing their timber framed “Frontal” walls. The experimental program was based on extensive dynamic testing on prototype representative of the current characteristic of “Frontal” walls. The results of the dynamic tests carried out in the LNEC 3D shaking table are presented regarding the two types of tests performed: (a) seismic tests, in which the seismic action was applied with increasing amplitude in the direction of the walls; (b) dynamic identification tests, aiming at evaluating the decrease of the mechanical properties of the models. A comparison of the performance of the non-strengthened and strengthened tested prototypes is also presented.

This paper describes a shaking-table experimental programme performed on four different multi-storey timber houses within the transnational Seismic Engineering Research Infrastructures for European Synergies (Series) project at the National Laboratory of Civil Engineering in Lisbon, Portugal. The aim of the Series project was to promote cooperation between main European research centres by giving access to their facilities. Under the timber buildings research programme within the Series framework, four real-scale three-storey buildings of plan dimension 7 × 5 m were assembled and tested: two timber-frame houses, one log house and one cross-glued laminated timber house. This paper describes the common parts of the various tests undertaken, such as the test set-up and the measurement layout. The tests themselves are described in a series of companion papers by the authors.

In the scope of the transnational access activities of the European research project SERIES, the Laboratorio Nacional de Engenharia Civil (LNEC) has provided access to its 3D shaking table to the international construction company Wienerberger AG and to a group of European experts, in order to perform full-scale seismic tests on an industrial solution for buildings using a modern unreinforced thermal insulation clay block masonry structure. Such solution represents a very common construction method in Central Europe and, although there are cyclic shear test results available, its effective dynamic response under seismic events still requires experimental validation. For this purpose, two full-scale mock-ups with different geometries were tested on the 3D shaking table using a series of seismic records with increasing intensity. This paper focuses on the most relevant experimental results regarding the structural response of the specimens, e.g., the dynamic response evolution, the collapse mechanism identified and the maximum drift values measured. The paper closes with the main conclusions drawn and with proposals for future developments.

Eurocode 8 imposes the use of reinforced solutions in order to ensure that the in-plane and out-of-plane damage of masonry infill walls due to seismic actions complies with given performance level requirements. Nevertheless, Eurocode 8 does not provide design rules or methodologies for the detailing of such reinforcement. An experimental programme was thus defined for assessing the response of innovative solutions for non-load bearing masonry enclosures using LNEC’s triaxial shake table. Two reinforcement solutions were tested on single leaf clay brick infill walls: (i) horizontal reinforcement in the bedding planes of the masonry units and (ii) reinforced mortar coating. Furthermore, a testing device for masonry infill panels was specifically conceived for this project. A detailed description of the methods used is given and the experimental results are partially presented and interpreted on the basis of the structural response and its evolution with damage.

Dissertação apresentada para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Ciências Empresariais, ramo gestão de PME Nesta época em que vivemos uma das mais graves crises económicas e a maioria dos mercados europeus e mundiais registam graves recessões, impõe-se um tempo de mudança de pensamento e de abordagem à gestão tradicional. Temas como a qualidade e o custo baixo adquirem relevância ainda maior na sobrevivência das empresas, visto que os mercados se encontram cada vez mais competitivos. Para isto, as empresas são forçadas a analisar com melhor detalhe e pormenor os seus processos e a redesenhá-los com vista à redução ou, em alguns casos, eliminação de tudo o que não acrescente valor para a empresa, ou seja, eliminação de desperdícios nos seus processos. A metodologia do sistema de produção Toyota embora iniciada e concebida no seio da produção, abrange todas as áreas de uma empresa, sendo transversal a toda a empresa desde a parte produtiva, administrativa, recursos humanos, qualidade, engenharia e até logística externa e interna. Esta ultima tem vindo a afirmar-se num contexto global, através da sua implementação em diversas empresas e consequente uso das suas ferramentas. Com isto, as empresas conseguem obter excelentes resultados na melhoria de qualidade, redução de custos, na relação com os seus clientes e até na melhoria de relacionamento interno entre os diversos departamentos. Esta dissertação pretende evidenciar através do estudo de caso único, como a aplicação de ferramentas e técnicas do sistema de produção Toyota no contexto real de uma empresa da indústria automóvel, que se encontra inserida num grande polo industrial de Setúbal como é o da Volkswagen Autoeuropa, pode proporcionar a criação e aumento de valor acrescentado e a eliminação de desperdícios nos seus processos. Para a realização deste estudo de caso da empresa Schnellecke recorreu-se ao estudo de inúmeras técnicas e ferramentas tais como a metodologia Lean, VSM, TPM, 5S, gestão visual, ferramentas da qualidade, os cinco porquês, poka yoke, sistema de controlo Kanban, processos uniformizados e folhas de processo, heijunka e Kaizen. Este estudo permite realçar a importância do sistema Toyota que se denota nos enormes ganhos obtidos tendo em conta os investimentos para a melhoria das situações. Abstract: In the time that we live one of the most serious economic crises in which most European and world markets are experiencing severe recessions, managers are inevitably shifting the thinking and approach from the traditional management. Issues like quality and low cost acquire even greater importance in the survival of firms because markets are increasingly the competitive. To do this, companies are forced to examine with better detail their processes and redesign them with tools to reduce, or in some cases eliminate everything that does not add value to the company, or in other words the elimination of waste in their processes. The methodology of the Toyota production system although initiated and conceived within the production , covers all areas of a company , being cross functional throughout the company since production , administrative, human resources , quality, engineering, internal and external logistics. This has been asserting itself in a global context, with several companies implementing it and using their tools to obtain excellent results in quality improvement, cost reduction, better relationship with its customers and to the improvement of internal relationships between different departments. This dissertation intents to show how using the unique case study in the application of tools and techniques of the Toyota Production System in the actual context of a company from the automotive industry which is inserted into a major industrial center in Setubal as the Volkswagen Autoeuropa, can provide creation and increase of value added and eliminating waste in their processes. For the realization of this case study in the company Schnellecke resorted to the study of numerous techniques and tools such as Lean, VSM, TPM, 5S, visual management, quality tools, the five whys, poka yoke, Kanban control system, standardized processes and methodology sheets process, heijunka and Kaizen. This study allows us to highlight the importance of this Toyota system that denotes the huge gains made taking into account the investments of improving the processes.

Seismic testing and analysis using large infrastructures, such as shaking tables and reaction walls, is performed worldwide requiring the use of complex instrumentation systems. To assure the accuracy of these systems, conformity assessment is needed to verify the compliance with standards and applications, and the Quality Management Systems (QMS) is being increasingly applied to domains where risk analysis is critical as a way to provide a formal recognition. This paper describes an approach to the assessment of the metrological performance of seismic shake tables as part of a QMS recognition, with the analysis of a case study of LNEC Seismic shake table.

Tese de doutoramento em Engenharia Civil (ramo do conhecimento em Estruturas), O parque habitacional de Portugal Continental contém algumas tipologias construtivas de elevada vulnerabilidade sísmica relativamente às quais urge actuar de modo a reduzir o risco sísmico a elas associado. No projecto de investigação “Mitigação do Risco Sísmico em Portugal Continental”, desenvolvido no Laboratório Nacional de Engenharia Civil (LNEC) e financiado pela Fundação para a Ciência e Tecnologia (FCT), foram identificados os edifícios “gaioleiros” como sendo aqueles que apresentavam o maior risco. Este tipo de edifícios, construídos entre meados do século XIX e princípios do século XX, é caracterizado pela aplicação de materiais de construção de fraca qualidade e de técnicas construtivas deficientes que têm como consequência uma elevada vulnerabilidade sísmica. Atendendo ao elevado número de edifícios existentes deste tipo, e às características relativamente uniformes que eles apresentam, justificava-se investigar soluções de reforço aplicáveis em larga escala que permitissem reduzir a sua vulnerabilidade. Partindo deste ponto, deu-se início aos trabalhos que são relatados na presente tese. Procedeuse ao estudo dos edifícios “gaioleiros”, de modo a seleccionar protótipos representativos da tipologia construtiva, e do comportamento sísmico de edifícios de alvenaria em geral. Foram analisadas várias técnicas de reforço, definidas genéricas tendo em vista o objectivo de aplicação em larga escala, e construídos modelos físicos para ensaio na plataforma sísmica triaxial do LNEC. Foram ensaiados ao todo cinco modelos e testadas três soluções de reforço distintas no âmbito do projecto supra citado, cujos resultados foram analisados qualitativamente e quantitativamente de modo a retirar o máximo de informações sobre o comportamento sísmico dos modelos não reforçados e reforçados. Obtiveram-se assim padrões de danos, propriedades dinâmicas, curvas de capacidade experimentais, evoluções de energias dissipadas, identificaram-se modos de colapso iminente e foram retiradas conclusões sobre a eficácia das soluções de reforço. Efectuou-se a transposição dos resultados experimentais para os modelos numéricos com o objectivo de avaliar a vulnerabilidade sísmica dos modelos e da tipologia. A realização de análises estáticas lineares e não lineares com modelos simplificados, baseados em macroelementos, permite captar a essência dos resultados experimentais. No final é possível apresentar também recomendações sobre reforços sísmicos., In the housing stock of Portugal Mainland there are several building typologies of high seismic vulnerability to which there is an urgency to act upon in order to reduce the seismic risk they present. In the research project titled “Mitigação do Risco Sísmico em Portugal Continental”, performed at “Laboratório Nacional de Engenharia Civil” (LNEC) and funded by “Fundação para a Ciência e Tecnologia” (FCT), the “gaioleiro” buildings have been identified as being the ones that pose the highest risk. This kind of buildings, built between the end of the XIX century and the beginning of the XX century, are characterised by the use of low quality building materials and substandard building techniques which are in turn responsible for their high seismic vulnerability. Since there is a large number of buildings of this kind existing nowadays, and because they are relatively uniform in their characteristics, it was found justifiable to search for strengthening solutions for large scale application in order to reduce their vulnerability. Starting from this point, the works concerning the present thesis have begun. A state of the art research was done on the “gaioleiro” buildings in order to select representative building typology prototypes, and on the seismic behaviour of masonry buildings in general. Several strengthening techniques were studied and defined in broad lines to be in accordance with the scope of the project, and physical models were built to test on the LNEC 3D shaking table. All in all, 5 models were tested as well as 3 strengthening techniques as part of the above mentioned research programme, the results of which were analysed in order to extract as much information as possible about the seismic behaviour of the unreinforced and reinforced models. This way damage patterns, dynamic properties, capacity curves and time-history energy dissipation were obtained, imminent collapse models were identified and conclusions were drawn about the effectiveness of the strengthening techniques. The gap between experimental results and numerical models was transposed with the aim to assess the seismic vulnerability of both the models and the typology. The static linear and nonlinear analysis performed with simplified models based on macroelements were able to capture the nature and essence of the experimental results. At the end are presented some recommendations concerning seismic reinforcements., Fundação para a Ciência e Tecnologia (FCT) - Bolsa de Doutoramento com a referência SFRH/BD/12469/2003