the INFOMED database analysis

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Assessment of RC hollow-piers for seismic limit state of damage - Direct repair costs

Due to the vulnerability of reinforced concrete hollow piers subjected to seismic actions, it becomes urgent to assess the expected shear damage and its evolution with the increase of the intensity level. Additionally, the focus of the scientific research dedicated to seismic behaviour of these elements is still reduced, in particular with regard to the limit states of damage and to the economic consequences of repairing and retrofitting the physical damages existing in RC hollow piers subjected to the seismic action. This information is deemed crucial when cost-benefit analysis is concerned for the definition of measures for repair and retrofit of seismic damage. This paper focus on the issue of damage to hollow piers due to the seismic action, proposing a methodology to characterize the limit states of damage under the perspective of the physical behaviour. It also intends to discuss adequate strengthening strategies and their direct costs, associated with each seismic physical limit state of damage. An extensive review of numerous cyclic experimental works on RC hollow piers will be performed, and in liaise with specialized construction companies, the direct repair costs will be estimated.6612-034D-AE05 | PEDRO DA SILVA DELGADON/

Seismic analysis of a Mexican viaduct with nonlinear modeling of soil-structure interaction

Every day the need to understand earthquakes and how that phenomenon affects construction grows, to make it possible to prevent and minimize inherent risks to their relation. That need increases when projects are located in regions with large seismicity. Therefore, the present paper, which was developed in partnership with GEG ? Gabinete de Estruturas e Geotecnia, has, as a final goal, to study and compare the variety of calculation methods available on Eurocode 8 to design and evaluate earthquake resistant structures, using a real case study. The methods approached are linear dynamic analysis, also known as spectral analysis, nonlinear static analysis, also recognized as pushover analysis, and non-linear dynamic analysis, well-known as time-history analysis. Simultaneously to the seismic analyses, it is developed a detailed study of the parameters that affect the damping of soil-structure interaction.6612-034D-AE05 | PEDRO DA SILVA DELGADON/

Health literacy, quality of life and burden of informal caregivers in Portugal

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findings from a Portuguese study

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Conception and justification of a new test setup for assessment of the fatigue strength of connections between precast railway bridge girders

Important investments have been made worldwide in the modernization and construction of railway lines. Plans for new constructions, have also been laid out. Recently, precast concrete has been widely employed in the construction of railway bridges and viaducts. Several precast solutions have been applied, namely: I-shaped or U-shaped precast girders and uni-cellular or bi-cellular precast box girders. Regarding the structural scheme in the longitudinal direction, either simple span or continuous decks have been used. In this context, this work aims to contribute to the knowledge about the real performance of these structures through the development of a laboratory tests setup, for the study of this type of structure, focusing on the connection between the precast beams. The setup will be implemented at the Laboratory of Earthquake and Structural Engineering (LESE), several experimental campaigns on the cyclic behaviour of reinforced concrete elements have been carried out.6612-034D-AE05 | PEDRO DA SILVA DELGADON/

Earthquake source effect and impact of the applied methodology to assess the overstrength factors of RC bridges

Seismic hazard assessment in several sites worldwide depends on two or more seismic sources. Many countries affected by subduction zones have strong motions earthquakes originated in at least two important seismic sources. In Mexico, interplate earthquakes (subduction process) have epicenters located in the Pacific coast with hypocenter depths less than 45 km and intraplate earthquakes (intermediate-depth earthquakes) normally have epicenters inside the continent with depth hypocenters greater than 45 km. Both seismic sources can potentially produce events with magnitudes Mw greater than 8.0 and, therefore, generate severe damage to the country's infrastructure. The design process of the bridges in Mexico is based on the chapter of Seismic Design of the Manual of Civil Structures of the Federal Electricity Commission. The standard allows to reduce the spectral ordinates of the design spectra by ductility and overstrength. It establishes an overstrength factor of 1.5 to reduce the design spectra, value not well supported by the Manual. This study evaluates the effect of the seismic source and methodology used to compute overstrength factors of common typologies of reinforced concrete bridges. The seismic capacity of the bridges was calculated with nonlinear static analysis and nonlinear time history analysis. The results showed that the importance of the seismic source on the overstrength factors depends on the seismic location of the bridges and, in general terms, nonlinear static analysis overestimates the bridges overstrength.6612-034D-AE05 | PEDRO DA SILVA DELGADON/

Overstrength factors of RC bridges supported on single and multi-column RC piers in Mexico

Mexico highway network has more than 14,000 bridges. Most of them are reinforced concrete (RC) structures. The bridges design process incorporates the use of an overstrength factor that is not justified and has received little attention in published works. Mexican regulations allow using an overstrength factor for buildings in the range of 2?3, to reduce the design spectra as a function of the selected seismic behavior factor. However, for bridges, a single factor of 1.5 is proposed independent of any design parameter. The bridges in Mexico are mostly simply supported structures with maximum span lengths of 50 m. A relevant and distinctive aspect of the bridges designed in Mexico is the large load amplitudes of the trucks used to define the live load and the high seismic activity in the country. This study determines overstrength factors of a family of medium-length RC bridges composed of simply supported superstructures and substructure made up of single and multi-column RC piers. Non-linear dynamic analyzes using a set of 80 accelerograms were carried out. The results show that the height of the bridges and their seismic location are relevant parameters in the overstrength of the structures. Finally, analytical expressions are proposed to assess the overstrength factors of a very common bridge typology in Mexico and the world.6612-034D-AE05 | PEDRO DA SILVA DELGADON/

a quantitative approach

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