1,720,972 research outputs found
Curved footbridges supported by a shell obtained as an envelope of thrust-lines
No full textSince Maillart’s curved arch bridges in concrete, different typologies of curved bridges in both steel and concrete have been constructed. On the contrary, since Musmeci’s shell supported bridge in Potenza, few shell bridges have been designed. This paper show how to design a curved shell supported footbridge shaping the shell by using the Thrust
Network Analysis. As a matter of fact, a shell supported footbridge is shaped between two curved arches, the one supporting the deck and with assighed layout depending on the layout of the road, and the one that defines the shell boundary at the lower part of the shell, the latter being found as a thrust line in the three-dimensional space. The influence of the boundary conditions on the bridge shape obtained as an envelope of thrust-lines is also investigated
Ponte in curva sorretto da gusci anticlastici speculari in cemento armato progettati con l’uso del metodo TNA (Thrust Network Analysis)
No full textDopo il primo ponte in curva in cemento armato realizzato da Robert Maillart, nella
seconda metà del novecento, e poi soprattutto in questi ultimi quindici anni, sono
stati costruiti numerosi ponti in curva di differenti tipologie, sia in acciaio che in
cemento armato. Al contrario, dopo la costruzione da parte di Sergio Musmeci del
Ponte sul Basento a Potenza, supportato da un guscio anticlastico in cemento
armato uniformemente compresso, solo un altro ponte a guscio significativo è stato
invece costruito. In questo articolo si mostra come dar forma a un ponte pedonale
in curva supportato da un guscio anticlastico in cemento armato, il cui form-finding
viene eseguito per mezzo di un ausiliario reticolo tridimensionale di curve funicolari
ottenute usando il metodo della Thrust Network Analysis (TNA). Viene quindi
illustrato il modo non convenzionale con il quale è stato applicato il metodo TNA
(altrimenti non utilizzabile in questo tipo di problema a causa della forma stessa del
guscio cercata), sfruttando alcune proprietà delle membrane anticlastiche. L’analisi
col Metodo degli Elementi Finiti (FEM) ha infine mostrato il buon comportamento
statico del ponte, evidenziando come la forma del guscio permetta di trasmettere i
carichi dell’impalcato verso le fondazioni principalmente tramite sforzi di
compressione, e dunque sfruttando al meglio le proprietà del calcestruzzo
minimizzando gli sforzi di trazione.Since Maillart’s curved arch bridges in concrete, different typologies of curved
bridges in both steel and concrete have been constructed. On the contrary, since
Musmeci’s shell supported bridge in Potenza, only one significant shell bridge has
been designed. In this paper it is shown how to design a curved footbridge
supported by an anticlastic concrete shell by shaping the average surface of the
shell by means of an auxiliary three-dimensional network of thrust lines (i.e.
applying the Thrust Network Analysis method). The paper shows how Thrust
Network Analysis (TNA) was applied for shaping the shell in an unconventional way,
through exploiting some peculiar characteristics of anticlastic membranes. FEM
analysis was finally carried out, showing how shell form is effective in transferring
deck loads to foundations, through exploiting concrete mechanical properties by
minimizing tensile stresses
Building Information Modeling and Geographic Information System: Integrated Framework in Support of Facility Management (FM)
Full text linkCurrently, the management of public real estate stocks is one of the most challenging activities. In this case, facility management emerges as a strategic but complex discipline that requires a great amount of integrated and structured data and information of heterogeneous origin and nature. Starting from this premise, this paper focuses on how FM discipline can be supported by Building Information Modeling (BIM) and Geographic Information System (GIS) integrated methodologies and tools achieving high levels of effectiveness and efficiency in public building stock management. This led to the definition and development of a framework that mainly takes advantage of open-source tools (e.g., Quantum Geographic Information System—QGIS, and Dynamo) and non-proprietary data exchange formats like the COBie (Construction Operations Building Information Exchange) international standard. This methodological framework is capable of integrating different but strongly complementary tools, data, information, and expert knowledge for a multiscale approach. The methodology presented in this paper does not provide for an integral transfer of BIM data to the GIS platform but leads instead to an effective bidirectional integration between the two informative systems, by properly relating them and allowing for an easy switch from one system database to the other. The findings of experimental applications of the methodological approach to the former Macciotta pediatric hospital, a healthcare building owned by the University of Cagliari, are presented and discussed. Finally, the analysis about potentials and criticalities of the developed methodological framework aims to trigger the widest future development and dissemination of this research
Curved deck arch bridges supported by an inclined arch
No full textCurved arch bridges with curved deck supported by an inclined arch either through web members or without are studied. Reference to shell-supported bridges is first made. It must be taken into account that even if the deck is supported by a shell, its bottom free edge (usually stiffened) is described by a thrust line, so that the shell connects the curved deck (that is a horizontal arch) with an inclined 3D funicular arch. A limit case is that the ring girder of the curved deck and the funicular arch merge dividing the shell into two parts, so that, if shell thickness tends to zero, no shell connects them. This is the case of curved bridges supported only at mid-span by an inclined arch. The efficiency of different arches is compared. Moreover, the deck can be supported not only at mid-span but also by web members connecting deck girder and inclined arch. In this latter case, the most appropriate form of the inclined arch is obtained
Comparison of form-finding methods to shape concrete shells for curved footbridges
No full textShells are attractive and efficient structures, that play a special role for engineers and architects. However, only few bridges supported by concrete shells have been designed and built after the Musmeci’s bridge in Potenza (Italy). Several numerical form-finding methods have been implemented in the last decades to optimize the shape of shells. In the present paper, a comparison of the Thrust Network Analysis (TNA) and Particle-Spring System (PS) is made by searching the optimal shape of a concrete shell supporting the curved cantilevered deck of a pedestrian bridge under the same boundary conditions. Finite Element Analysis were performed to compare the structural behaviour of the footbridges optimized by the two different form-finding techniques. The effectiveness of both form-finding methods in minimizing unfavourable tensile stresses in concrete shells, thus taking advantage of mechanical properties of concrete, is investigated. Furthermore, transverse deflections of the curved cantilevered deck were reduced introducing an external prestressing system applied to the upper flange of the ring box girder. Finally, the obtained results can help architecture and engineering practitioners to develop innovative bridge conceptual design
Renewable energy communities design: A decision support tool for integrated impact assessment. Insights from the first REC in Cagliari, Italy
Full text linkRenewable Energy Communities (RECs) play a crucial role in advancing the European green transition and achieving key environmental, social, and economic objectives, such as reducing carbon emissions, improving energy efficiency, and ensuring affordable energy access for disadvantaged and low-income populations. However, most research and initiatives tend to address these issues in isolation, thereby overlooking the full potential of RECs. This paper presents an integrated approach led by a multidisciplinary team from the University of Cagliari and the Municipality of Cagliari (Italy), aimed at establishing the first REC in Cagliari, Italy. The project was established in a social housing neighbourhood to comprehensively address complex social, economic, and environmental needs. A participatory design methodology was adopted to actively involve residents, fostering community engagement and raising awareness of the benefits of RECs, thereby promoting long-term community commitment. A key contribution of this work is the introduction of a decision support tool developed to model energy and cash flows, as well as environmental benefits, thereby optimizing energy consumption, financial outcomes, and CO2 reduction. The case study offers an empirical evaluation of both design and implementation phases, assessing the project's feasibility and overall impact. The tool is designed to be highly replicable in other contexts, particularly for addressing energy poverty in public housing neighbourhoods. The findings highlight also underscore its broader policy implications, demonstrating its usefulness for public administrations and stakeholders in guiding investment and planning decisions that prioritize social value over profit
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
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
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