256 research outputs found
Valutazione sperimentale delle caratteristiche meccaniche di muratura di tufo per modelli in scala intermedia
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La sicurezza di murature esistenti in relazione alla resistenza a compressione: considerazioni con riferimento ad un caso reale
No full textSeismic performance evaluation for steel MRF: non linear dynamic and static analyses
No full textThe performance of steel MRF with rigid connections, proportioned by adopting different capacity design criteria, is evaluated in order to highlight the effectiveness of static non-linear procedure in predicting the structural seismic behavior. In the framework of the performance-based design, some considerations are made on the basis of the results obtained by both dynamic time histories and push-over analyses, particularly with reference to the damage level and the structure ability to withstand a strong earthquake
Dal legame costitutivo alla capacità rotazionale di blocchi murari: indagine sperimentale su murature storiche in tufo
No full textComportamento di elementi murari sottoposti ad azioni orizzontali cicliche: Indagine sperimentale
No full textMajor constraints on the use of radiocarbon dating for tephrochronology
No full textIt is well recognized that radiocarbon dating is a powerful tool capable of providing a detailed chronostratigraphy for areas that have been subjected to recurrent volcanic activity during Late Pleistocene and Holocene time. In such geological contexts carbon-bearing materials suitable for 14C dating are, for the most part, refractory componetns of pedosphere (e.g. palaesol humic matter) and organic detritus (e.g. charred/uncharred remains of higher plants) which occur within the tephra suites. Since such materials derive initially from atmospheric carbon dioxide, as well as record significant lapses in volcanic activity, it is then often assumed that these conditions comply ideallly with the fundamental requirements of the radiocarbon dating theory. However, two recent 14C dating programmes based on materials from the volcanic districts of the Phlegrean Fields and the island of Procida (Campania, southern Italy) yielded evidence to the contrary and, in turn, gave rise to concern over the validity of the 14C dating method when applied in volcanic regions. In particular, it has been found that the conventional radiocarbon ages recorded by modern tree-leaves from the caldera of Solfatra volcano range from 'modern' to ca. 5000 yr BP. Furthermore, the magnitude of the age anomaly is determined by the pattern of localised dilution of the mean atmospheric 14C concentration by juvenile (14C-free and 13C-enriched) carbon dioxide issuing from nearby volcanic vents. In the case of paleosols, a series of 14C measurements on different chemical fractions isolated from the humic matter in a suite of four paleosol horizons entrained in tephra deposits at Procida island yielded, for each paleosol horizon, a systematic ca. 2000 yr scatter of 14C ages. It is shown that such intrasoil age differences, which reflect the origin and history of humic constituents, can be used to afford a better definition of the true paleosol age
L’adeguamento sismico dell’edilizia ordinaria in muratura alla luce della nuova normativa
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