Assessing urban and building vulnerabilities connected to the emergency management: an integrated methodology

In Italy, three are the common strategies applied to assess seismic vulnerability: structural analysis of existing buildings, semi-empirical analysis of urban systems (e.g. the one published in 2004 by the Region of Emilia- Romagna) and the ‘Emergency Limit Condition’ analysis of emergency plan systems. The aim of the research is to combine these approaches together into an integrated methodology to identify which urban areas are more vulnerable and the possible reasons: structural behaviour, infrastructural design, interaction with the emergency plan system. The methodology was applied to ‘Villaggio Prealpino’, a neighbourhood (101 hab/ha) in Brescia between 1950 and 1970 by ‘La Famiglia’ cooperatives. These cooperatives built about 30000 houses in 135 neighbourhoods (Lombardy and other regions), producing remarkable examples of social housing. Firstly, through a Geographic Information System based software, the urban system of the neighbourhood was analysed: inhabitants, residential and commercial buildings, infrastructural system. Secondly, their influence in emergency situations management was understood, considering: road widths, building heights and their structural vulnerability. This was computed by filling in the ‘2nd level form’ (realized by Gruppo Nazionale per la Difesa dai Terremoti). Finally, results were properly combined, to find the location of the most vulnerable areas. Through the integrated methodology it was possible to relate at the same time the vulnerabilities of urban systems, buildings and emergency plan systems, finding the weak points of an urban area during seismic events. The case study showed vulnerabilities in building constructions and infrastructural system. Due to the widespread construction technique (hollow brick masonry) and the few architecture typologies (e.g. two-story duplex), experimental tests have been done to analyse this kind of structures (previous studies show their seismic vulnerability) and to design a reinforcement. The aim is to provide local authorities with a methodology to understand where it is important to plan risk mitigation actions.