1,721,025 research outputs found
Bequinot C, Galasso G., Petriccione S., Turco C. — Problemi demografici italiani e questione meridionale; La Calabre. Une région sous-développée de l'Europe méditerranéenne
No full textC A. Bequinot C, Galasso G., Petriccione S., Turco C. — Problemi demografici italiani e questione meridionale; La Calabre. Une région sous-développée de l'Europe méditerranéenne. In: Population, 15ᵉ année, n°5, 1960. pp. 910-911
REXEL 2.2 beta: uno strumento per la selezione di accelerogrammi naturali per le NTC e l’Eurocodice 8
No full textNon‐linear dynamic analysis is recognized as the more accurate tool for seismic evaluation of structures in the case of both probabilistic assessment and design. The key issue in performing this kind of analysis is the selection of appropriate seismic input (e.g., real records), which should allow for a correct and accurate estimation of the seismic performance on the basis of the seismic threat at the site where the structure is located. In this paper, the prescriptions of the new Italian building code and of the Eurocode 8 on the topic are briefly reviewed and a tool for computer-aided real record selection is presented. The software, available at http://www.reluis.it/, allows to define the design spectra according to the two codes for any site in Italy and to search for sets of 7 records compatible, in the average, with them
Toward EEW engineering applications: lead-time maps for the ISNet infrastructure in the Campanian region (southern Italy)
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Dal workshop RELUIS-INGV-DPC di Capri a REXEL: uno strumento software per la selezione automatica dell’input sismico per l’analisi dinamica non-lineare delle strutture secondo le NTC
No full textL’analisi dinamica non lineare è considerata il metodo di simulazione numerica più accurato tra quelli disponibili per valutare il rischio sismico di opere civili. Tuttavia, oltre che una modellazione adatta a cogliere opportunamente il comportamento ciclico degli elementi, richiede una accurata valutazione della sismicità a cui è soggetto il sito in esame e la conseguente selezione dei segnali sismici da utilizzarsi. Questo è un punto che può necessitare di competenze sismologiche di base tipicamente extra-curriculari rispetto alla formazione del professionista. Infatti, l’azione di progetto è spesso definita sotto forma di spettro di accelerazione atteso in relazione proprio alla pericolosità sismica. Gli accelerogrammi da utilizzare nelle analisi devono poi in qualche modo essere compatibili con esso, oltre che riflettere una serie di altri parametri caratterizzanti il moto al suolo e/o le sorgenti dei terremoti pericolosi per il sito
Information-dependent lead-time maps for earthquake early warning in the Campania Region
No full textFeasibility of earthquake early warning systems (EEWS) depends on the possibility of immediately detecting the earthquake’s characteristics and on the ability to design applications for real-time seismic risk mitigation. Rapid estimation of event’s features (as magnitude and location) is the focus of real-time seismology; the second issue requires particular attention of engineers. Among the information needed to design EEW engineering applications (and to evaluate the effectiveness of EEWS) there is the estimation of the available time to perform security actions before the arrival of the more energetic seismic phase at the site of interest; this interval is termed lead-time. The study presented herein examines the distributions of the available lead-time in the Campania (southern Italy) region. The study considers events occurring in the area covered by the ISNet (Irpinia Seismic Network) infrastructure and assumes a spatially-uniform distribution for the hypocenters. Under these hypotheses the minimum, maximum and average lead-times were computed. Also the uncertainties associated to the information provided by the ISNet are considered in order to evaluate the lead-time; in fact, there is a trade-off between the amount of warning time and the level of information available to predict the peak ground shaking. Results of the analyses, presented in form of maps, confirm that evacuation of building is hardly possible in the region, although the available warning time seems to be sufficient to activate personal and/or automated security measures
Uncertainly analysis of flexural overstrength for capacity design of RC beams
No full textTo ensure an overall ductile structural behavior, the reinforcing steel used in the seismic design of reinforced concrete (RC) structures is governed by certain specific requirements given in many international codes, such as the Eurocodes and the recently released Italian Building Code (IBC). This study's primary focus is the statistical analysis of reinforcing steel properties, based on data from over 600 material tests. The data sets considered include a wide range of reinforcing steel bars (from 12 to 26 mm) provided by different Italian industries and used for a large structure built in Naples (Southern Italy). The test results are analyzed to determine the appropriate cumulative distribution function for yield and ultimate strengths, as well as the ultimate deformation, and other statistical parameters of interest as defined in the codes. The comparison with previous tests confirms an improvement in the quality of materials, as reflected in reduced variability and increased bias factors, consistent with other investigators' recent findings. Finally, this study investigates the flexural overstrength of RC beams designed according to the current IBC - consistent with Eurocodes - and the accuracy of code requirements in light of realistic material models both for concrete and reinforcing steel and of uncertainties associated with mechanical models, structural members geometry, and material properties (as obtained in this study for reinforcing steel). The obtained results show that code provisions do not seem conservative and provide a basis for an improved calibration of future editions of seismic design codes for buildings
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