3rd Croatian Conference on Earthquake Engineering 3CroCEE

On March 22, 2020, the capital of Croatia, Zagreb, was struck by a devastating earthquake that caused damage to many buildings. The most affected were the structures in the city center, constructed as buildings in aggregates, which are characterized by their architectural style and construction methods typical of urban environments from the Austro-Hungarian Monarchy period of the 19th century. In addition to these, standalone family homes situated at the epicenter also sustained great damage. Following the earthquake, engineers who volunteered to help citizens and the city were deployed to the field to conduct rapid inspections of the damaged buildings. Thanks to their response and the previous years of efforts by experts in the field of earthquake engineering to gather knowledge on preparedness and response to seismic events, the Zagreb building fund acquired a long-desired and extremely important database regarding its buildings. Based on this database, which includes over 25,000 assessments of earthquake damage, data on the damage and usability of buildings after the Zagreb earthquake were collected for systematic and statistical analysis in this study. The aim of the research is to conclude how the response of a building in aggregate is influenced by neighboring buildings, considering their interconnection (shared or separate gable walls) and the different or identical arrangement of various parameters. The parameters observed include the position of the building in aggregate (corner position/position within the block), the height relationship of neighboring buildings (two sides/annexes), the regularity of the structure (in height/floor plan), the position of the ceiling structure of neighboring buildings (same level or not), and the openings position and arrangement. This paper analyzes the aforementioned parameters and draws conclusions regarding the vulnerability level caused by the same factors.