# Seismic Vulnerability Assessment of Historical Masonry Buildings in Croatian Coastal Area
## 2 Seismic Vulnerability Assessment of the Test Site  
### Description of the Test Site  
The selected test site for the application of the methodology developed in the project is Kastel Kambelovac, one of the seven settlements comprising the town of Kastela (Figure 1). The relevant area covers around 45,000 m\({}^{2}\) and includes more than 400 buildings. The settlement consists of a historical core with stone masonry buildings built between the 15 th and 19 th centuries (Figure 2) and of the parts outside the historical core dating from the beginning of the 20 th century to the present (the north, east and, west parts are shown in Figure 3). These buildings were constructed in different periods according to different technical regulations. The oldest buildings were constructed before 1948; then, some blocks were erected from 1949 to 1964, from 1964 to 1982, and from 1982 to 2005. The most modern buildings have been built from 2005 onwards.  
The buildings in the historic center were constructed with stone blocks with mortar joints, the walls' thickness being between 45 and 75 cm. The structural frame is characterized by wooden floors consisting of beams and a wooden floor covering. The quality of the walls depends on the processing of the stone, their way of stacking, and on the quality of the mortar in the joints. The walls' textures vary from rough non-squared stone masonry of variable size arranged in a chaotic manner, to well-organized masonry made of well-shaped or cut blocks of almost uniform size (Figure 4). The mortar is mainly of a low quality. The buildings were constructed without confining elements and with poor connections between the walls and floors. Some of these buildings were then reconstructed and wooden floors were replaced with monolith reinforced concrete plates.  
Some buildings are in very poor condition, without mortar in the joints between the stone blocks, significant cracks in the load-bearing walls and, in some cases, with collapsed roofs (Figure 5). Several buildings are completely demolished.  
Figure 1: Town of Kastela: (**a**) protected architectural heritage of the town of Kastela; (**b**) a view of an old historical core, Kastel Kambelovac [39].  
Figure 3: Kästel Kambelovac test site with four characteristic parts.  
Figure 2: Historic center with typical buildings, Kästel Kambelovac.  
Figure 4: Examples of wall textures of stone masonry buildings: (**a**) non-squared roughly shaped stone masonry of various sizes arranged in chaotic manner; (**b**) wall composed of disorganized roughly shaped stones; (**c**) walls made of natural well-worked homogenous squared stones accurately executed; (**d**) walls of St. Mihovil church, composed of well-organized cut blocks.  
Figure 5: Current state of buildings in the historic centre: (**a**) damage to Cambi tower; (**b**) completely demolished building; (**c**,**d**) significant cracks in the load-bearing walls of residential buildings.  
The general problem with assessing the earthquake vulnerability of these buildings is that most of them are private residential buildings. Some of them have been reconstructed and upgraded. The most common reconstruction interventions are the replacement of flexible ceilings with RC slabs and the replacement of old roofs. In some buildings, new floors were added during the reconstruction. In some buildings, new floors were added during the reconstruction. These processes were often carried out illegally and were not documented. The lack of documentation is also a major issue in defining the structural characteristics of these buildings.  
Generally, buildings have a low level of safety with regard to earthquake events. The lack of free space in the enclosed area resulted in a high urban density. The buildings lean one against the other and have merged into blocks with narrow streets. This high density represents an additional safety problem for the population in the event of an earthquake.