1,720,996 research outputs found
Structural behaviour of masonry vaults according to architectural types
Over time vaulted masonry elements have been designed to withstand mainly symmetrical permanent
load conditions (e.g. due to own weight), but many other environmental actions, such as earthquakes,
may produce asymmetrical loads, which can undermine the whole structural system. Recent seismic
events in Italy highlighted the vulnerability of masonry structures, in particular of vaulted structures,
which should be somehow limited by applying preventive structural interventions. To interpret correctly
the structural behaviour of masonry vaults, it is necessary to take account for their interaction with the
entire building organism as well as to consider the relevant resisting mechanisms, which is governed
by internal stresses induced by the static and dynamic loads and by any existing structural pathology.
This paper aims at better understanding the structural response of vaulted masonry elements, based
on the historical constructional periods, architectural style and geometrical types, in order to acquire
useful information for a preventive analysis of the major potential structural vulnerabilities in case of
seismic events
Typological classification of vaulted structures in masonry churches
The damage analysis of historical masonry buildings and in particular of churches, following the
seismic events that recently affected the Italian territory, has shown how vaults and domes, which
represent architectural valuable elements, are characterized by a very high structural vulnerability.
Over the centuries, master builders, architects and engineers designed and built vaults relying on
intuition and practical geometry knowledge, especially with in situ experience. The construction
techniques of vaulted structures varied according to the skills of the different builders, as well as the
choice of materials depended on socio-economic factors and the formal result to be achieved.
Architectural treatises concerning the “best practice”, between the 15th and the 19th centuries, greatly
influenced the design and constructional procedures of vaulted structures, providing indications on the
proportions and geometric shapes to be adopted. Based on this premise, this paper provides a
typological classification of existing structural types in order to identify geometric and structural
affinities among different vaulted architectural elements
Residence time distribution of food suspensions containing large particles when flowing in tubular systems
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
Influenza delle modalità di essiccazione e delle condizioni operative sulla qualità di alcuni ortaggi essiccati
Large-Scale Analysis of Masonry Bell Towers in Naples
Masonry bell towers often represent a distinctive element of the Italian landscape. Their different typological, constructive, and structural peculiarities, along with the great exposure given by their relevant artistic value, make them both structurally and seismically vulnerable. Since the conservation of masonry bell towers requires a multidisciplinary approach, the PREVENT project (Integrated PRocedure for assEssing and improVing the resiliENce of existing masonry bell Towers on a territorial scale) aims at defining a two-level procedure for assessment and enhancement, at both a territorial and architectural scale. In this paper, the preliminary results that emerged from the first census carried out on a surveyed population of 56 masonry bell towers in the city of Naples (Italy), are presented. A classification has been made from a geometric-typological point of view, in order to frame their structural peculiarities. Also, preliminary assessments of the dynamic behaviour of a sub-sample of 40 masonry tower bell towers (i.e. excluding the bell-gables and double tower types) have been carried out. Further analyses will allow the elaboration of “resilience” indexes, as synthetic indicators of the architectural, historic, and cultural value, as well as of the structural safety, of the considered bell towers
Parametric Investigation on the Effectiveness of FRM-Retrofitting in Masonry Buttressed Arches
Buttressed arches represent some of the most vulnerable elements in historical masonry buildings under seismic actions. Given their structural, architectural and often artistic importance, it is paramount to investigate effective retrofitting measures which satisfy reversibility and compatibility requirements for historical heritage. Among these, Fibre-Reinforced Mortar (FRM), characterised by enhanced ductility, has recently emerged in the scientific literature. In this paper, a numerical investigation aimed at exploring the effectiveness of this seismic retrofitting technique, when applied at intrados or extrados of various typologies of buttressed arches, is presented. An automatic tool for limit analysis is described and validated against a nonlinear Discrete Macro-Element modelling approach. This precedes an extensive parametric analysis, which has highlighted the effect of various geometrical features of the system on both collapse mechanism and maximum acceleration in the unreinforced configuration, and the high increase in seismic capacity provided by the retrofitting. This is particularly remarkable in case of local mechanism, i.e., wholly within the arch, in which case the FRM may be responsible of an overall shifting to a semi-global failure type
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