## 3 Description of the Case-Study Hospital Building
### As-Built State of the Hospital Building  
General Hospital Dubrovnik (Figure 2) is a key building for the functioning of hospital services and rescue actions after potential earthquakes in the Dubrovnik-Neretva County, and is located in the most seismically-active region of Croatia with the reference peak ground accelerations exceeding 0.3 g for 475 years with return period earthquakes. The building was designed and constructed in the 1980s. It has two stories below and eight stories above ground level, including the ground floor. The story heights are 4.5 m in the first two stories above ground level and 3.2 m in higher stories. The building is compact, but irregular in its plan (Figure 3) and height is. The outer building dimensions in the plan are approximately 51 \(\times\) 43 m and its height above ground is approximately 28 m. The gross floor area of the ground floor and first story is 2123 m\({}^{2}\), while the area of higher floors is 1537 m\({}^{2}\). Figure 2: Building photographs: (**a**) south facade; (**b**) north facade; (**c**) north-east facades. The original building documentation was collected from the city and the hospital archives. The dimensions of the structural elements were obtained from the drawings accompanying the original static design and checked on-site. It was confirmed that the as-built state mostly corresponds to the designed one. A reinforcement check was partially performed using a device for the ultrasonic testing of the reinforcement. Reinforcement spacing was identified for particular structural elements, but the rebar diameter and built-in reinforcement in some of the beams could be been reliably detected. Therefore, it was assumed to be in accordance with the static design and construction practices applied in the 1980s. The building is compact, but irregular in plan, which is unfavorable for its structural seismic performance. Eccentricities in the building seismic response may cause significant forces in the structural elements located near the edge of the structure. It is also irregular in height according to Eurocode 8-1 [29]. It is constructed of reinforced concrete MB30 (C25/30) with smooth steel GA 240/360. The main load-bearing system consists of RC walls, mostly of 25 cm thickness, which continuously extend from the foundations to the roof, while the partition RC walls are not regular in height. The frame system negligibly contributes to the horizontal load-bearing capacity. RC walls are connected by coupled beams. In some elevations along the height, coupled beams are relatively deep (from 100 cm to 230 cm) and it may be assumed that they are part of the wall system. The partition walls are made mostly of reinforced concrete, 7 and 10 cm thick, and of gypsum. The sanitary facilities are mostly constructed with prefabricated RC panels with ribbed reinforcement and are linked to floors and ceilings by discrete connections. These panels have a certain stiffness and contribute to the building response due to ambient vibrations. However, it may be expected that these connections will break or that the hinge will be formed during intense ground shaking, so partition elements may lose their load-bearing capacity. However, it is not presented in the paper. Figure 3: Layout of the story 3 (ground floor). Figure 4 presents the layout of stories three (ground floor) and five (the third story above ground level), where structural (grey) and non-structural RC elements (blue) may be observed. As it may be noticed from the figure, the cross-sectional area of all structural walls is much larger at the story three (ground floor) than at the story five (third story above ground level). As it will be shown later, the critical structural elements are located mostly at story five. Moreover, it may be observed from Figure 3 that the area of the walls in the Y direction is smaller (2.47%) compared to X direction (2.89%); therefore, earthquake loading in this direction would probably be more detrimental.