## 2 Case Study  
### General Features and Geometrical Description  
The municipality of Orihuela is located in the south of Alicante province. It has a population of 78,505 inhabitants [18] and covers an area of 365.5 km\({}^{2}\), making it the largest municipality in the province. Orihuela is divided into several districts, some near the sea and others inland. The majority of the city's heritage is located in the Historic Center, which was declared a Historic-Artistic Site in 1969 and was one of the first to receive such a designation in Spain. The Historic Center contains numerous monuments, many of which are designated as Assets of Cultural Interest, along with various ecclesiastical and civil buildings such as churches, monasteries, convents, hermitages, palaces, and bourgeois houses from different centuries. Orihuela's selection as a monitored area is notable due to its location in a region of moderate seismic activity. Hospitals are critical infrastructure that must remain operational during and after an earthquake, making them an important case study for earthquake preparations. The hospital located in Orihuela, Spain (Hospital Vega de Bajja; Case study), was constructed in 1988 as a mid-rise building using reinforced concrete. The ductility of the building is moderate, and the floors consist of bidirectional reinforced concrete slabs with a total thickness of 19 cm except for the basement, which features a unidirectional concrete slab. The infill panels of the reinforced concrete frames have been built with brick masonry walls. The building has been divided into 15 structurally independent zones, which are connected by joints that serve both a structural and expansion purpose. In this study, only one of the sectors identified as block number 14 was considered (see Figure 1). This building serves as a valuable resource to understand the general dynamic behaviour of mid-rise pre-high-seismic code reinforced concrete buildings in the Orihuela area. Given the report of seismic vulnerability of the Valencian Community [19] during the 1984-1994 period, there was an improvement in the stiffness of floor elements due to the update of regulations, including the EH-85 and EH-88 instructions. Additionally, the quality of construction and materials experienced some improvement during this period, with structural concrete approaching medium to high quality. The EH-91 instruction also resulted in increased technical and control requirements. In terms of seismic-resistant design during this period, what was indicated for the previous period remained essentially unchanged. However, there was a gradual incorporation of better structural analysis and software, and most buildings from 5-6 storeys were designed considering wind loads to improve their conditions in low and moderate seismicity areas. Therefore, in the case of the Hospital Vega Baja, constructed in 1988, its design would have been influenced by the code instructions that were in force during the 1984-1988 period. The building would have been designed with a focus on improving the stiffness of the floor elements and with a higher quality of construction and materials, particularly in  
Figure 1: General plan view of the hospital Vega de Baja and location of block 14.  
terms of the structural concrete used. The seismic-resistant design would have followed the guidelines from the previous period (i.e., 1970-1984), as the NCSE-94 [1] code was introduced later and thus could not have influenced the design of the hospital. Moreover, it is important to note that each time the seismic code was updated, there was typically a transition period before the new rules became compulsory. Thus, the design of the hospital in 1988 did not incorporate the changes introduced by the NCSE-94. In this study, different parts of the same beam member were analysed to account for variations in capacities due to effective reinforcements at both ends (denoted as 'e') and at the mid-span (denoted as'm') of each beam.