PSI - Issue 44

Gabriella Tocchi et al. / Procedia Structural Integrity 44 (2023) 1972–1979 Gabriella Tocchi et al./ Structural Integrity Procedia 00 (2022) 000–000

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municipal areas. The procedure will be tested for two different municipalities in the same region to demonstrate its applicability and results. 2. Analysis of Cartis database The 1st level “Cartis” form (Zuccaro et al. 2015), developed within 2014-2016 Reluis project, financed by Italian Department of Civil Protection (DPC), supports the compilation of regional scale inventories and the use of more refined vulnerability models. For each municipality investigated, the form is compiled interviewing a local expert, such as an engineer or an architect with a deep knowledge of the built environmental in the study area. The first step for compiling the form is to divide the municipal area in Town Compartments (TC), sub-areas characterized by homogeneity of the building stock in terms of period of construction, construction techniques and/or structural types. Based on the study of historical documents and/or cartographies, a map of the municipal area with the delimitation of the TCs can be compiled. The TCs in a municipality are numbered and usually the first TC (i.e., TC 01) may correspond to the more ancient area of the city, that is the historical center, the second TC (i.e., TC 02) to the first expansion area, the third to the following expansion area and so on till the newest construction areas. Then, the interviewed technician should provide the percentage occurrence of prevalent masonry and reinforced concrete (RC) building typologies within each TC and for each building typology the related structural and non-structural features should be identified. For example, a masonry building typology in a given TC should be described in terms of period of construction, type of vertical structures (e.g. irregular layout or regular layout), slab’s type (e.g. flexible, rigid or semi-rigid slabs, vaults), presence of tie rods or tie beams as well as the relative position of the building in the block (corner, external, internal, insulated). Nowadays, more than 500 municipalities are investigated by Cartis covering different Italian regions. Analyzing the distribution of these municipalities in different population classes (C pop ), defined based on the number of inhabitants (< 500, C pop = 1; 501- 2000, C pop = 2; 2001-5000, C pop = 3; 5001-10000, C pop = 4; 10001-50000, C pop p = 5; 50001-250000, C pop = 6;> 250000, C pop = 7), it can be observed that the 93% of the municipalities included in the database have between 500 and 50000 inhabitants (e.g., belong to population class from 2 to 5), while only the 2% have less than 500 inhabitants and 5% more than 50000.

Fig. 1. Average percentages of buildings build before 1945 (a) and between 1946-1981 (b) belonging to different TCs. The percentages reported are calculated considering all municipalities investigated by Cartis in population class 4, but similar percentage can be observed considering other population classes. It can also be noted that the number of TCs defined for a municipality generally depend on the number of inhabitants (i.e., the population class). Thus, on average, in municipalities belonging to C pop =1 or C pop = 2 most of the buildings (about 75%) are included in the first two TCs (e.g., TC 01 the historical center and TC 02 the expansion area), while a similar percentage of buildings is covered by 3 different TCs for municipalities in higher population classes (C pop 4 or 5). Concerning the period of construction, a correlation between age of buildings and the relative TC to which they belong show that usually round the 70% of buildings built before 1945 belong to the first compartment (i.e., TC 01 the historical center), while about the 60% of buildings built between 1946 and 1981 belong to TC 02, independently from the population class (Fig. 1).