# Seismic Vulnerability Assessment of Historical Masonry Buildings in Croatian Coastal Area
## 2 Seismic Vulnerability Assessment of the Test Site
### Vulnerability Index Results
As shown in Figure 9c, the buildings were distributed between vulnerability classes A to D, with 1%, 16%, 68%, and 15% of the buildings, respectively. The \"position of the building and foundation\" parameter considers the influence of the local morphology of the site and the natural slope of the ground. Its distribution in Figure 9d showed a low level of vulnerability. Specifically, 57% of buildings were in class A and 43% were in class B. The reason for such a distribution is the presence of solid soil of type A and the relatively small slope of the terrain. The \"typology of floors\" parameter evaluates the in-plane stiffness of the floor and the presence of efficient floor-to-wall connections. The buildings were distributed between vulnerability classes A to D, with 19%, 0%, 3% and 78% of buildings, respectively (Figure 9e). The reason for this high percentage of buildings in class D is the presence of wooden floors which were poorly connected to the walls. Regarding the parameter of \"plainmetric configuration\", which measures the regularity of the planimetric shape of the building, 8%, 17%, 23%, and 52% of the buildings were distributed in vulnerability classes A to D, respectively (Figure 9f). The most populated classes were C and D, because a high level of horizontal irregularity was detected. The \"elevation configuration\" parameter evaluates vertical regularity through the analysis of the stiffness of different floors, the presence of porticos, lodges, towers, and other structural elements which affect the distribution of the masses at each floor. In terms of this parameter, 19%, 11%, 41%, and 29% of the buildings belonged to vulnerability classes A to D, respectively, as displayed in Figure 9g, with classes C and D proving to be most relevant. Figure 9: Spatial distribution of the 11 parameters that comprise the seismic vulnerability index: (**a**) type and organization of the resistant system; (**b**) quality of the resistant system; (**c**) conventional resistance; (**d**) position of the building and foundation; (**e**) typology of floors; (**f**) planimetric configuration; (**g**) elevation configuration; (**h**) maximum distance among walls; (**i**) roof; (**j**) non-structural elements; (**k**) state of conservation. The \"maximum distance among the walls\" parameter validates the presence of structural walls orthogonally connected to transversal ones. The buildings in the historical core had a favorable distribution, as most of them belonged to classes A and B, with 69% in class A, 12% in class B, 13% in class C, and 5% in class D, as shown in Figure 9h. In terms of the parameter \"root\", which evaluates the roof's typology and weight, buildings were distributed among vulnerability classes A to D, with 9%, 40%, 15%, and 36% of the buildings, respectively (Figure 9i). The presence of \"nonstructural elements\", which can cause damages due to falling, highlighted an area of high vulnerability because most buildings had weakly connected nonstructural elements and belonged to classes C and D. The distribution shown in Figure 9j was 12%, 0%, 53%, and 35% for classes A to D, respectively. The \"state of conservation\" parameter analyzes the condition of the building and the presence of cracks in structural walls. The relevant distribution, shown in Figure 9k, was as follows: 27% were in class A, 0% in B, 45% in C, and 28% were in class D. Most old stone masonry buildings, which have not yet been reconstructed, are in a bad condition and belong to classes C and D, whereas reconstructed buildings are in class A.