The present paper describes the collapses in precast industrial buildings caused by the 2012 Emilia earthquake. This kind of buildings, not designed with seismic criteria, has been found very vulnerable for several reasons, such as the absence of connecting systems between the various precast monolithic elements, the inadequacy of connection systems of external precast walls to the bearing elements (columns and beams), the interaction between non-structural walls and structural elements, and the inadequacy of the foundations.
earthquake
Earthquake Insurance in Italy: Is It Possible?
Since a long time, the State, founded on solidarity principles, intervenes and indemnifies the earthquake damage suffered by citizens, assuming the reconstruction cost. In these last years the Parliament tried repeatedly to shift, almost in part, the damage compensation to the insurance system. A lot of draft laws on the theme didn’t have success. The April 6 2009 earthquake in Abruzzo region proposed again the problem concerning the very high cost of reconstruction intervention, emphasized by the very singular Government’s choice, condensed into the slogan “from the tents to the houses”. In this article are analysed same fundamental aspects concerning damage compensation, pointing to the needs to establish a close connection among the prevention action, still very small in the country, and the possibility that the insurance system could play a relevant role in the reconstruction phase.
For this paper is available an extended abstract after the text in Italian
The Mapping of Post-Earthquake Damage Scenarios in Support of Municipal Emergency Plans
Nel presente lavoro viene proposta una metodologia, chiamata SCE-PEC, per la rappresentazione di scenari di danno post-sisma /1/, finalizzati agli obiettivi della pianificazione comunale dell’emergenza sismica /2,3/. Uno scenario di danno post-sisma contiene informazioni essenziali per la pianificazione delle attività delle Funzioni di Supporto /4,5/. Detta metodologia utilizza vari tipi di mappe con differenti livelli di elaborazione e sintesi: mappe di base, mappe di danno, mappe di sintesi e mappe per funzioni di supporto. La metodologia SCE-PEC è di tipo modulare e pertanto è possible applicarla parzialmente o integrarla con infor- mazioni aggiuntive.
For this paper is available an extended abstract after the text in Italian
Railway station of underground line under seismic action
The dynamic behaviour of a railway station of the Underground line of Milan is analysed under the effects of an earthquake defined according to Eurocode 8, with peak ground acceleration of 0.07g.
The analysis requires the preliminary knowledge of the state of stress and strain in the soil surrounding the tunnel. It depends on the geometry and on the mechanical properties of the soil layers, which are generally non-homogeneous and non-isotropic. Besides, the state depends on excavation and construction procedures. The computer code FLAC, 2004 version, is proved to be capable of representing this state fairly, the main limitation resting on the knowledge of the constitutive law of the soil and on the representation of excavation and construction procedures. In this paper this state of stress and strain is briefly reviewed. It will be referred to as the relaxation state of stress. If the ground is exposed to seismic excitation, the resulting state of stress in the surrounding soil and the sheet-piling is computed by integrating the equilibrium equations during the earthquake duration, with reference to the non-linear behaviour of the soil. Starting from the relaxation state of stress, the program executes the integration step by step, updating the soil properties according to the total strain amplitude. The sheet-piling and the vertical wall of the station are not linked by steel bars and are kept in contact by the earth pressure. The gap between the two structures may be open during the seismic event, depending on the conditions of the tendons. In the model this element is represented by apposite gap elements, able to follow the contact condition. The reinforced concrete structures remain in the linear elastic realm, in practice. Severe damage to this type of structures, although small in number, was caused in Kobe, Japan, by the disastrous Hygo-Ken Nanbu (Kobe) earthquake of 1995. The worst damage to the large-scale underground facilities was the collapse of the Dakai Underground Station in Kobe, pertaining to the underground railway (Kobe Rapid Transit). Other damages have been reported for railways station in occasion of the Athens Earthquake of 1999.
For this paper is available an extended abstract after the text in Italian