Ensaios sísmicos inovadores de pórticos com paredes de enchimento em alvenaria

Foi recentemente desenvolvido no LNEC um dispositivo e uma metodologia experimentais para a realização de ensaios sísmicos em paredes de alvenaria de enchimento inseridas em pórticos de betão armado, representativos do comportamento de um painel de parede num edifício submetido a uma solicitação sísmica bidireccional. Para esse fim, a base do pórtico a ensaiar é fixa à mesa sísmica e a viga superior é ligada a uma parede de reacção. O movimento da mesa na direcção do plano da parede implica dessa forma a imposição de uma deformação relativa, dinâmica, entre o topo e a base do pórtico. Ao mesmo tempo, uma estrutura auxiliar garante que o movimento dinâmico da mesa, na direcção perpendicular, é imposto como um movimento de corpo rígido ao pórtico, deixando a parede em vibração forçada devido às forças de inércia que se desenvolvem para fora do seu plano

Common damages and recommendations for the seismic retrofitting of vernacular dwellings

This closure chapter acknowledges the most common retrofitting elements and measures identified in vernacular architecture. It enhances common systematic structural damage and failure mechanisms during earthquakes, relating them with probable causes, and establishing general recommend ations to consider in preventive and reactive actions. Also, recommendations for the design and detailing of new construction in prone earthquake areas are advancedPortuguese Science and Technology Foundation (FCT) to the research project ‘SEISMIC - V – Vernacular Seismic Culture in Portugal’ (PTDC/ATP - AQI/ 3934/2012

Fuzzy inference systems for multi-step ahead daily inflow forecasting

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOThis paper presents the evaluation of a daily inflow forecasting model using a tool that facilitates the analysis of mathematical models for hydroelectric plants. The model is based on a Fuzzy Inference System. An offline version of the Expectation Maximi371129144FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO2011/09178-1This work was supported by FAPESP, Brazilian Agency dedicated to the development of science and technology (Process: 2011/09178-1); and by the AES Tietê company (Process: 37-P-17852-2010

Seismic-V: vernacular seismic culture in Portugal

For a long time, reactive seismic retrofitting was focused on monumental heritage and very little on vernacular architecture. In the last years, there has been a growing interest on seismic resistant design and solutions and several research units emerged to produce important research in the scientific field. However, for some time, international focus to address earthquake-damaged buildings was on intrusive techniques and technological materials to retrofit monuments. This paper aims to explore how the research project SEISMIC-V intends to fill the gap regarding this critical research problem. The research will contribute to the awareness and protection of the local seismic culture. The project outcomes will provide data for the strengthening of seismic-resistant architectural components in in-use vernacular heritage.Fundação para a Ciência e a Tecnologia (FCT

Metaheuristic Approaches for Hydropower System Scheduling

This paper deals with the short-term scheduling problem of hydropower systems. The objective is to meet the daily energy demand in an economic and safe way. The individuality of the generating units and the nonlinearity of their efficiency curves are taken into account. The mathematical model is formulated as a dynamic, mixed integer, nonlinear, nonconvex, combinatorial, and multiobjective optimization problem. We propose two solution methods using metaheuristic approaches. They combine Genetic Algorithm with Strength Pareto Evolutionary Algorithm and Ant Colony Optimization. Both approaches are divided into two phases. In the first one, to maximize the plant’s net generation, the problem is solved for each hour of the day (static dispatch). In the second phase, to minimize the units’ switching on-off, the day is considered as a whole (dynamic dispatch). The proposed methodology is applied to two Brazilian hydroelectric plants, in cascade, that belong to the national interconnected system. The nondominated solutions from both approaches are presented. All of them meet demand respecting the physical, electrical, and hydraulic constraints

Evaluation of seismic vulnerability assessment parameters for portuguese vernacular constructions with nonlinear numerical analysis

Considering that vernacular architecture may bear important lessons on hazard mitigation and that well-constructed examples showing traditional seismic resistant features can present far less vulnerability than expected, this study aims at understanding the resisting mechanisms and seismic behavior of vernacular buildings through detailed finite element modeling and nonlinear static (pushover) analysis. This paper focuses specifically on a type of vernacular rammed earth constructions found in the Portuguese region of Alentejo. Several rammed earth constructions found in the region were selected and studied in terms of dimensions, architectural layout, structural solutions, construction materials and detailing and, as a result, a reference model was built, which intends to be a simplified representative example of these constructions, gathering the most common characteristics. Different parameters that may affect the seismic response of this type of vernacular constructions have been identified and a numerical parametric study was defined aiming at evaluating and quantifying their influence in the seismic behavior of this type of vernacular buildings. This paper is part of an ongoing research which includes the development of a simplified methodology for assessing the seismic vulnerability of vernacular buildings, based on vulnerability index evaluation methods.(undefined

Assessment of innovative solutions for non-load bearing masonry enclosures

This paper presents some of the results of the research project “Masonry Enclosures” developed in the framework of the transnational access (TA) to LNEC’s triaxial shake table within the FP7 project SERIES.In order to ensure that in-plane and out-of-plane damage of masonry infill walls due to seismic actions complies with the performance levels’ requirements, Eurocode 8 imposes the use of reinforced solutions. Nevertheless, it does not provide any design rules or methodologies for such reinforced masonry enclosures. 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.(undefined

Assessment of layer thickness and uniformity in railway embankments with Ground Penetrating Radar

In the aim of a national research project entitled “Interaction soil-rail track for high speed trains”, a protocol was established between the National Railway Network and four national research institutions to develop the knowledge concerning the methodology for the construction and quality control of the railway embankments and railtrack layers for high speed trains. One of the objectives of this protocol is to establish a methodology for quality control of construction layers by different available test methods. Nondestructive testing (NDT) methods are currently very attractive due to their ability to provide information about layer thickness and state condition without causing damage or requiring the removal of material samples. Within the NDT available, ground penetrating radar (GPR) is a very fast and reliable technique, whose advantage is the repeatability and the capability of acquiring continuous data. To reach the proposed goal, a trial embankment was constructed with different materials, layer’s thicknesses, water contents and compaction energy levels. GPR was used in two embankments, in order to detect the thickness of the sub-ballast layer located over the compacted sand layer and its uniformity along the track, but also along the cross-section of the track. In order to control some parameters of the sub-ballast layer, like thickness and uniformity, several metallic plates had been used in the base of the sub-ballast layer, along an alignment. It shows clearly the ability of GPR to detect the sub-ballast layer and its thickness variations along the profile