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Structural fire performance of earthquake-resistant composite steel-concrete frames
No full textSeismic and fire design of a building structure maybe two very demanding tasks, especially if included in a performance based design philosophy. For the time being, the necessary harmonization on the regulations concerning these two design fields is almost missing, thus preventing the effective possibility of an integrated design. Besides, while many countries have already moved towards the use of performance-based codes for seismic design, the application of such methodologies for the fire design of structures is still limited in scope. Within this framework, the development of suitable procedures introducing structural fire performance issues for a comprehensive design methodology is needed.
In this paper, a numerical investigation for the assessment of the structural fire performance of earthquake resistant composite steel-concrete frames is presented. With reference to a case study defined in the framework of a European Research Project, a great effort was devoted to the identification of the key structural parameters allowing for a possible correlation between the predictable performances under seismic and fire loadings, when these two are considered as independent actions.
At the conceptual design level, the most suitable structural solution with respect to both design actions was chosen, including composite beams and circular steel concrete-filled columns. The frame was designed in order to resist severe seismic action according to the ductile design approach provided by Eurocode 8; the parameters affecting members' sizing were outlined in this phase. Afterwards, the seismic performance of the designed frame was investigated by means of non-linear static analyses; once the seismic performance objectives were met, in order to evaluate the structural fire performance of the whole frame a set of criteria was defined. To this purpose, thermo-mechanical analyses under different boundary conditions were developed and in order to identify the possible mechanisms leading to structural failure, the state of stress at the critical cross-sections at different times of fire exposure was investigated. Another point of main concern was represented by the assessment of the influence of different restraining conditions on the achieved fire resistance rating and kind of structural failure.
Moreover, the proposed methodology allowed making an estimate of the amount of axial restraint provided to the heated beams by the surrounding structure: in this view, the importance of choosing column elements in function of their flexural stiffness was revealed, in order to correlate it with the predictable performances under both seismic and fire loadings
Restauro statico di una volta laterizia in folio per sollevamento e rinforzo estradossale., Bollettino Ingegneri,
No full textNel presente lavoro si descrive il restauro statico riguardante una volta in folio di laterizio risalente al XVII secolo, a decorazione di un ambiente in un palazzo del centro pisano, caratterizzata da una ricca decorazione in affresco e stucchi in gesso in intradosso ed in condizioni di incipiente collasso tali da non consentire operazioni dal basso. L’intervento è stato effettuato esclusivamente dall’estradosso, compresa l’opera di sollevamento per il ripristino dell’originaria conformazione geometrica ed il successivo rinforzo, nel rispetto dei materiali costituenti le dcorazioni. L’intervento è stato preceduto da prove sperimentali sulle caratteristiche meccaniche delle murature e sul particolare di sollevamento, nonché accompagnato da una modellazione numerica agli elementi finiti per la valutazione delle cause del dissesto e degli effetti del rinforzo
Prestazioni in caso di incendio di telai sismo-resistenti in soluzione composta acciaio-calcestruzzo
No full textLow-rise buildings equipped with Flag-Shaped Hystretic Devices (FSHD) and R.C. shear walls
No full textSeismic and fire design of composite frames – A comprehensive methodology for an integrated design
No full textSteel-concrete composite frames with rigid full-strength connections for seismic and fire loadings
No full textDesign and performance evaluation of bare steel and composite Moment Resisting Frames subjected to seismic and fire loadings
No full textProgettazione duttile di telai composti acciaio-calcestruzzo con colonne tipo “concrete filled”
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
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