1,720,963 research outputs found
The northern arch of the Augustus Bridge in Narni.
No full textThe Augustus Bridge is a monumental bridge viaduct on the river Nera, north of the town of Narni, built in Roman times and attributed to the reorganization of the Via Flaminia made by Augustus (27 BC). The bridge is made up of four arches, of which only the first survives to the south, has always been a source of admiration for the size and the shape and has been the subject of technical studies and artistic representations. In recent times it has been the subject of some laser surveys and of various structural models, also via finite elements, moreover, also following some seismic events, works have been made to consolidate the surviving parts. Despite the various studies, due to the changes that have taken place over the centuries, both due to natural collapses and due to degradation from anthropic actions, there are still many questions that have not received a precise answer: the slope with the exact dimensions for the arches, the shape of the access routes, the origin of the materials, the absence of breakwaters, the diversity of the shape of the remaining piers and arches. In the present work, the authors, as a complement to papers written in the last years, have focused on the appearance of the northern arch of the bridge, which has a particular ribbed shape, indicated by various authors to be similar in some respects to the roofing vault of the temple of Diana in Nimes, and after having sought its diffusion in other Roman contexts, they also studied its structural behavior through a series of finite element models
THE FOURTH ARCH OF THE AUGUSTUS BRIDGE AT NARNI (ITALY): A CASE STUDY OF ROMAN ARCH WITH RIBS
No full textThe roman bridge said of Augustus (27 BC) is a monumental viaduct on the Nera River, north of the town of Narni. The bridge is made up of four arches, of which only the first survives to the south, has always been a source of admiration for the size and the shape and has been the subject of technical studies and artistic representations. The remains of the fourth arch, the northernmost, show a very particular ribbed appearance, noted by many authors, among all: Balance, Choisy and Galliazzo. Some authors indicate the fourth arch to be similar in some respects to other arched structures (bridges or basilicas roofs), for example to the roofing vault of the temple of Diana in Nimes or to the Roman bridge in Nimreh, ancient Namara, in Syria. The authors of the present study, through a bibliographic research, having verified the diffusion of this shape in other Roman contexts, believe that at to date there do not seem to be other similar examples. The fourth arch appears to be unique in relation to the arrangement of the voussoirs, which are set to be more connected than a simple overlap of elements. However, the different radial depth of the voussoirs could have caused less effectiveness, especially in relation to possible movements related to the thrust of the arch on the springer and in concurrence with the second (from the south) pier subsidence with possible detachment and the consequent collapse of the central voussoirs. The subsidence of the second pier, which finally collapsed in 1885, is indicated by many authors as the main cause of the collapse of the central arch. In this work, the study of the subsidence and collapse of the second pier is also investigated through 3D FEM modeling of the pier and of the entire bridge. Finally, a set of 3D FEM models was presented to analyze the structural feature of the fourth arch of the Augustus Bridge, the executive assembly modalities, especially in the keystone area, compared to the same arch without emptiness among the ribs
The Sanctuary of Santa Maria delle Grazie at Fornò. A FEM approach to seismic structural analysis
No full textThe Sanctuary of Santa Maria delle Grazie at Fornò, located in the countryside near Forli, was constructed between 1450 and the early years of the sixteenth century. The Sanctuary externally consists of a circular masonry structure 15 m high and 33 m in diameter, with four semi-circular niches protruding to the outside; inside, a similar circular structure 20 meters high delimits a central area, covered by an octagonal dome. The space between the two circular structures is covered with a wooden roof resting on thirty-six main wooden beams. The building has been subject to various interventions due both by static requirements (i.e. damage caused by several historical earthquakes), both for changes related to epoch's style (the four semicircular niches realized in 1686). Finally, the events of World War II, with the demolition of the bell tower and part of the adjacent monastery, have brought the building back to the clear original shape. Recently an entire laser survey was carried out, providing comprehensive measurements for reconstructing the Sanctuary’s shape and overall size. After the laser survey, several structural analyses are executed. Lately it was possible to study the effect of the possible consolidation works under the strain, even seismic, expected by the new national rules particularly in the light of the guidelines (2011) for the "Assessment and reduction of seismic risk of cultural heritage with regarding to the technical standards for construction in DM 14/01/2008 "
The Sanctuary of Santa Maria delle Grazie at Fornò: studies for the restoration and seismic strengthening.
No full textThe Sanctuary of “Santa Maria delle Grazie” is located at Fornò in the countryside near Forlì (Italy). The first temple, built in 1450, assumes today's configuration at the beginning of the sixteenth century, to undergo various modifications, due to static necessities and to changes in tastes related to the time, as well as due natural disasters and war damage. Structurally, the Sanctuary consists of an external masonry cylinder, around 33m diameter and 15m in height, with four semicircular niches protruding outwardly; inside there is a similar concentric structure, the oldest temple, about 14m diameter and 20m tall, covered by a dome supported by an octagonal masonry structure. The space between the two circular structures is covered with a wooden roof resting on thirty-six main wooden beams. In the last years the Sanctuary has been subjected to numerous studies, surveys and analysis, including FEM structural analysis (also due to singular curvilinear typology of the masonry structures). In regard to the seismic risk, the building was studied focusing on the Guidelines (2011) for the "Evaluation and Reduction of Seismic Risk of Cultural Heritage.". Today, following the entry into force of the new technical standards NTC2018 (January 2018) we have scheduled an update of the structural analysis and a series of proposals for restoration, anti-seismic improvement and dehumidification works, in regard to the effects of decay caused by soaking on the mechanical characteristics of the masonry
Seismic Strengthening of Existing RC Structure Through External 3D Exoskeleton
Full text linkThe seismic hazard in the southern regions of Europe is known as one of the most critical issues when
considering the improvement of the existing buildings in terms of energy and structural behavior. The use of
integrated plug-and-play systems can be a solution to the most common obstacles occurring during the
different phases in the building practices: from the design to the realization. Within the framework of the
European project Pro-GET-onE, a case of structural strengthening obtained by applying a steel exoskeleton
connected to the reinforced concrete (RC) structures of an existing building has been presented. The
modelling, the linear and non-linear analyses were conducted with finite element software. They have been
implemented for the pilot case of Athens, and the results have been achieved in relation to different
parameters such as PGA, shear exploitation and displacement in the plastic phase. This approach determines
an increase in the global stiffness of the structural system with a consequent reduction in displacements.
Depending on the actual plasticization of the RC frames, the resulting excursion in the plastic phase of the
exoskeleton is proven to provide a dissipation of extra energy and a stiffness increase in the existing building
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
