Description
On March 20, 2020, Zagreb was hit by a strong earthquake with a magnitude of 5.5 on the Richter scale, with the epicenter located 7 km away from the city center. A large number of buildings in the city center were damaged, as they were dating back to the late 19th and early 20th centuries. After the earthquake in Zagreb, the area of Petrinja, which is approximately 40 km away from Zagreb, was struck by a 6.2 magnitude earthquake on the Richter scale, further damaging buildings in Zagreb. The subject of this study is the presentation of in situ tests on the existing structure and structural strenghtening of the existing structure of the Faculty of Political Sciences building at the University of Zagreb. The building is consisted of 3 blocks connected into one unit. The load-bearing structure of the building is a reinforced concrete frame system (column- beam). Filling between frames is masonry made of solid bricks. The floor structure is reinforced concrete ribbed slabs, which is characteristic for the construction period around the mid-20th century from which building dates. Structure has six floors above ground. This paper presents the initial condition and categorization of damage after the earthquake, as well as the in situ tests on the existing load-bearing structure. Through input parameters of the data provided from existing structural properties, an numerical analysis of the existing condition and the current capacity of the load-bearing structure under seismic action was performed. Based on the results, a retrofitted numerical model was developed and analyzed. Result of analysis is achieved capacity under seismic action. Finally, the implemented retrofitting interventions on the load-bearing structure in the construction phase is given along with the description
