PSI - Issue 44

Giorgia Cianchino et al. / Procedia Structural Integrity 44 (2023) 219–226 Giorgia Cianchino et al. / Structural Integrity Procedia 00 (2022) 000–000

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mortar (Rapone et al., 2018). In both cases, the applied construction techniques followed essentially rules of thumb defined on the basis of the practical experience gained from the several earthquakes that stroke the region over the last centuries. For the definition of archetypes, 34 municipalities, located in different altimetric zones of Abruzzi, were considered. Using the afore-mentioned procedure proposed by (Basaglia et al. 2021), able to dialogue with the online database reporting the CARTIS data for all the investigated municipalities, it was possible to select the main structural features (hereafter referred as parameters) of the buildings therein located and to identify a total number of 26 URM archetype buildings as representative of the whole stock of unreinforced masonry buildings in the region. Six of these archetypes are analyzed in this paper. Their selection was driven by the presence of similar characteristics in terms of slabs, roofs and lack of anti-seismic devices, while ensuring differences in what concerns the vertical load-bearing structure (irregular stonemasonry or brick masonry) and the number of stories (2, 3 or 4). Such a choice was made in order to assess how much the number of stories does ultimately affect the vulnerability of URM archetypes (both for irregular and regular masonry). Table 1 summarizes the significant parameters of the six archetype buildings considered for this study. Based on the geometric and structural information collected, ideal models were also created for each of them, as shown in Fig. 2 for building “archetype #1”. Table 1. URM archetypal buildings for the Abruzzi region (by percentage relevance) based on CARTIS data. The numbering of the archetypes corresponds to the order identified in (Basaglia et al., 2021)

Number of Stories 3 Stories 4 Stories 2 Stories 3 Stories 4 Stories 2 Stories

Roof Material

Construction Period

Ring Beams and Tie Rods

Slab Type

Wall thickness > 60 cm > 60 cm < 60 cm < 60 cm < 60 cm > 60 cm

Distance between walls

# Masonry Type

1 Irregular masonry - Without courses 9 Irregular masonry - Without courses

< 1860 < 1860 < 1860 < 1860 < 1860 < 1860

Absent Absent Absent Absent Absent Absent

Flexible Flexible Flexible Flexible Flexible Flexible

Light Light Light Light Light Light

< 5 m < 5 m < 5 m < 5 m < 5 m < 5 m

17 Brick masonry 19 Brick masonry 21 Brick masonry

22 Irregular masonry - Without courses

3d view – Frontal facade

Back façade

First floor

Longitudinal section

Figure 2. Ideal model representative of archetype #1

3. Analytical method

Linear and nonlinear kinematic analyses for local mechanisms were performed on the main macroelements of the six archetype buildings. The analyzed kinematic mechanisms are related to the total or partial overturning of the fa ҫ ades, namely those mechanisms that are most likely to be activated under earthquake actions for the studied typology. In fact, the selected URM buildings do not have tie rods or any other type of restraining elements between orthogonal walls. Therefore, other kinematics (such as in-plane mechanisms) were considered less probable.