Ambient-noise measurements for seismic risk mitigation of school buildings

Abstract: Seismic risk management of relevant and strategic structures is a notable issue in seismic Italian codes. In order to delineate a rational strategy for seismic risk mitigation on a wide territory, it is necessary to create some decision-making tools useful to define a prioritization of intervention. For this purpose, useful data have to be collected for each structure involved on the territory. The method of ambient-noise measurement on the structure, that is a rapid and cheap technique for acquiring directly the data, is presented in this work. This technique permits to analyse the data within an holistic framework, considering both site effects and structural dynamical characteristics. It is therefore possible to check the presence of some vulnerability parameters that can increase the propension to damage of the building. These parameters are both connected to site amplification factors and to structural seismic behavior, that can heighten the stresses on particular structural elements. Further, joined analysis of site and structure permits to identify the presence of double resonance effects, that are known to be perilous for the structure. Some example of application of the method are presented for school buildings of Friuli Venezia Giulia Region (NE of Italy), that have been analysed during ASSESS project

Seismic safety design of sprinkler systems. Comparison between FM global and NTC 2008

The recent main earthquakes in Italy (Emilia, 2012, Abruzzo, 2009) highlighted the importance of seismic design of plants in particular in the industrial sector. Indeed, in such cases, the indirect costs due to the out of services of the plants and the consequent production losses are very high and greater than the direct costs of reconstruction/reparation of the plant. For this reason, often, the insurance companies require that the principal plants (such as the sprinkler system) should be seismically designed. In case of an earthquake, the seismic design of sprinkler systems has to ensure the strength and the stability in order to avoid accidental ruptures and onerous out of services. In Italy, the seismic design of the plants became mandatory after July 2009 with the entering into force of the NTC 2008 standard. Nevertheless, foreign insurance standards, such as FM Global, are usually adopted in Italy for the seismic design of sprinklers. This practice raises the following question: "Is a sprinkler designed according to the requirements of FM standards compliant with the NTC 2008'". This paper illustrates a comparative analysis between FM Global and the NTC 2008, highlighting the differences in terms of seismic action and strength. Finally, practical abacuses, for identifying the cases in which the FM-Global provides solutions that are in compliance with the NTC 2008 are presented. Copyright \ua9 2015, AIDIC Servizi S.r.l

Criteri per la definizione delle priorita' di intervento su edifici scolastici costruiti o adeguati prima dell entrata in vigore delle NTC2008.

Il presente lavoro definisce dei criteri per stabilire le priorit\ue0 di intervento per l\u2019adeguamento sismico degli edifici esistenti in base all\u2019analisi dell\u2019evoluzione delle prescrizioni normative. Le norme si sono adeguate alle nuove conoscenze acquisite nel campo del calcolo sismico, sia per quanto riguarda la capacit\ue0 che la domanda e di conseguenza anche edifici gi\ue0 progettati come antisismici possono presentare livelli di sicurezza diversi da quelli attualmente richiesti. Sono state definite delle soglie che consentono di collocare ogni edificio in una classe di prestazione sismica che rappresenta il livello di adeguatezza rispetto alle norme attuali; permette quindi di costruire una scala di priorit\ue0 di intervento