1,720,958 research outputs found
Application to an urban bridge stock of a prioritization procedure based on seismic assessment compared with the novel Italian guidelines
Full text linkThe challenge of large-stock maintenance with limited budget is faced by administrations in charge which need tools for management and intervention prioritization. This need is especially perceived for bridges which are strategic structures and represent crucial elements in roadway networks. Since 2016, a combined prioritization procedure has been applied to the bridge stock of the Municipality of Padova (Italy) to assess both the condition state, accounting for degradation, and the seismic vulnerability. The proposed methodology evaluates the level of degradation through visual inspections and type-specific forms for the defect survey, while the seismic vulnerability is assessed by means of fragility curves previously obtained by the authors for typical Italian bridges. This contribution focuses on the application of the seismic-based prioritization. The identification of the bridge typologies which appeared to be more seismically fragile is presented, comparing this aspect with results from the recently issued novel Italian Guidelines for the management of existing bridges
RC tied-arch bridges: Typological analysis for the definition of retrofit interventions
Full text linkThe Italian bridge asset is characterized by aged structures, most of which made of reinforced concrete, needing retrofit interventions to improve both their seismic performance and load-bearing capacity towards the increased traffic volume. In order to provide a series of guidelines for retrofit, a research project, carried out by the ReLUIS consortium supported by the Italian Department of Civil Protection, aims to identifying typological deficiencies and vulnerability of the main type of bridges widespread on the Italian territory, defining typological interventions. This paper presents the outcomes of the ongoing research focusing on RC tied-arch bridges, frequently built in the period between the two world wars. A typological study was carried out to define the main design deficiencies and construction details, and how degradation acts on this type of bridge, besides the main structural vulnerability to both gravitational and seismic loads. Numerical and parametrical analyses were carried out on a representative prototype tied-arch bridge with RC hangers, dating back to 1930s. The structural behavior was assessed by means of numerical analysis on FEM models, allowing the evaluation of the static and seismic capacity, the definition of the most vulnerable elements, and thus, the identification of the most suitable type of retrofit interventions
Priority-ranking procedure to assess seismic vulnerability of school buildings at territorial scale
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Dynamic Identification and Calibration of an Arch Steel Bridge Model for the Evaluation of Corrosion Effects
No full textBridges play a crucial role as they are critical elements in several road networks. Recent trends in condition state assessment require to evaluate not only the seismic vulnerability and the load carrying capacity for increased traffic loads, but also the damage state due to decay and environmental effects. in order to evaluate the structural reliability of the bridge and define priority lists for interventions on the network. In the framework of a series of inspections carried out at a municipality level for the above mentioned aims, a numerical and experimental analysis was carried out on a historical steel deck arch bridge, called Paleocapa bridge, located in the historic city centre of Padova (Italy). Paleocapa bridge is composed by six arches and is highly vulnerable to traffic load, due to a widespread and advanced corrosion state. In order to study the effects of both internal and external boundaries and the loss of mass and stiffness due to steel corrosion a parametric modal analysis was implemented. The steel material was characterized through uniaxial tensile test and metallographic and chemical analysis, while a dynamic identification test of the bridge was performed in order to extract modal parameters, i.e. natural frequencies, damping ratios and mode shapes. Modal analysis pointed out a decoupled behaviour of arches and deck, and among the same arches, with a consequent significant decrease in load-bearing capacity. The calibrated FE model of the bridge was used to assess the seismic and static capacity of the structure. In particular, the latter was very critical; therefore, it was necessary to limit the transitable load on the deck, in agreement with the public authority
Characterisation of an urban bridge portfolio and multi-risk prioritisation accounting for deterioration and seismic vulnerability
Full text linkThis contribution proposes a procedure to prioritise retrofit interventions on stocks of bridges according to their seismic vulnerability. The procedure also combines a previously presented approach to evaluate deterioration effects on bridges at a territorial scale. Thereby, the combi-nation of the two approaches provides a multi-risk classification method for bridge stocks. This method also allows refined prioritisation within each class, based on the proposed quantitative indices and on multicriteria decision-making methods. The method was applied to the bridge stock managed by the municipality of Padova, in North-East Italy. First, an extensive charac-terisation of the analysed stock is provided, according to typological, geometric, and structural parameters. Then, the application of the combined approach is presented, highlighting which bridge types resulted more vulnerable to either seismic actions or deterioration effects
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
- …
