GNGTS 2013 - Atti del 32° Convegno Nazionale

capacity design (hierarchy of strength, construction details of the beam-column joint, spacing of transverse reinforcement, etc.). In the following a study on the evolution of seismic zoning of the national territory from 1909 to the present day has been used. Therefore for each municipality it can be assessed, on the basis of the time intervals defined by ISTAT, typically over ten years, how many and how long the changes in seismic zoning have concerned the municipality. Afterwards it is possible to obtain the vulnerability curves representative of a RC Building dating back to a determined age of construction for a specific municipality, as the weighted average of the vulnerability curves corresponding to the different seismic zoning (zone I, zone II, zone III) that have affected the municipality, depending on their respective percentage of occurrence in that time interval. Results. Input d ata, for each building, are represented by: 1. Building Typology; 2. Number of storeys; 3. Plan Irregularity; 4. Age of construction; 5. Soil type. Field survey provides exhaustively data about global building dimensions, besides the age of construction and soil type. Based on the latter information, the Building Type (Rubble stone, Simple stone, Unreinforced Masonry for Masonry Buildings and Non-designed class or low ductility class for RC Buildings) is determined according to the chapter ‟Census dataˮ. In particular the information about Soil type is used to define a multiplier factor f PGA of the PGA that generate a seismic action able to produce on a certain building category and a certain class of height, built on a certain soil, the same effect if it was built on Rock (Ground Type A). According to I-PGA correlations to a PGA factor f PGA an Intensity Increment ΔI corresponds and hence a Vulnerability Increment DV (Giovinazzi and Lagomarsino, 2004). According to the same work plan irregularity produces a fixed Vulnerability Increment (+0.04). Fig. 2 – Mean damage value as a function of: a) number of storeys of surveyed buildings; b) age of construction of surveyed buildings; c) error in the number of storeys of LIDAR data; d) error in Building Typology and age of construction of LIDAR data. a) b) c) d) 55 GNGTS 2013 S essione 2.1