GNGTS 2016 - Atti del 35° Convegno Nazionale

GNGTS 2016 S essione 2.3 425 INTEGRATED SURVEY TO SEISMIC RISK ANALYSIS, RESILIENCE reduction and planning G. Cascini, B. Murgante, M. Vona Scuola di Ingegneria, Università della Basilicata, Potenza, Italy Introduction. To mitigate the seismic risk and to reduce the economic direct and indirect losses, a synergic work based on the best practice is need using rational criteria by all those involved. Moreover, to improve the resilience of the cities, the seismic risk mitigation must be considered as a fundamental phase in mitigation strategies (Tilio et al. , 2012). Due to the large amount of buildings that require seismic retrofitting and the limited available resources, the correct spatial and temporal resources distribution should be based on objective distribution strategies. In order to implement retrofitting strategies of the buildings, firstly each decision maker must be able to identify the main characteristics of the buildings. The morphological, geometrical, and structural information about town, her streets, buildings and their aggregation play a fundamental role. The work would like to provide tools able to define direct the fundamental information for seismic risk mitigation, based on scientifically accurate assessments of geometric characteristics of the buildings. Moreover, the other part of the work is define the first survey of damage status of buildings after buildings, overcoming the use of tools based on expert and empirical evaluation. Particularly, the existing tools and methods are unable to provide a correct assessment the characteristics of the buildings and their interaction between seismic risk mitigation necessity and urban planning. In the paper, the results of survey of a damaged historic centre have been reported. The survey has been carried out using an integrated approach between different survey methodologies and tools. The ���� ������ case ������ study. In Italy, there is a significant number of historical centre that became ghost town. Generally, several natural events could be started the relocation of the villages. In this work, a typological characterization of a damaged historical centre is reported. The case study is the historical centre of Romagnano al Monte (Salerno, south of Italy). The types of buildings seems almost similar with some differences for more recent buildings the more recent part of the village. The buildings in the historical centre are small size (up to 2-3 storeys) and typically have a rubble masonry structure, with poor construction quality, and were frequently connected in heterogeneous structural aggregates. In the more recent zones, structural types had somewhat heterogeneous characteristics: rubble, concrete block, and brick masonry were present, often variously combined in the same structure with several types of floor. Moreover, some framed RC buildings built after the 1960’s were present. After November 23, 1980, (MW=6.8 (CPTI15, Italian Parametric Earthquake Catalogue 2015), for Romagnano al Monte the macroseismic intensity was characterised by value of IMCS = VIII-IX, the village has been strongly damaged but not destroyed like other nearby towns. A few months after the 1980 Irpinia earthquake, on the basis of high damage levels and mainly for mostly existing socio-economic problems, the Romagnano al Monte was forsaken (Vona et al. , 2016). The relocalisation was therefore decided also and the historical centre became a ghost town. Then Romagnano al Monte is “frozen” in the 1980 post - earthquake condition. For these reason, Romagnano al Monte has been selected in order to apply and validate same techniques and procedures to survey types of buildings and the first survey of post earthquake damage. Survey methodologies. The knowledge of vulnerability of the buildings is a key step to mitigate the seismic risk. Several studies have been carried out to assess the vulnerability of the buildings based different approaches as the observed damage and its correlation with typologies characteristics. In order to apply these different approaches, a fundamental role is played from the quality