# Seismic Isolation Devices for Protecting RC Buildings: The Frangipane School in Reggio Calabria
## 3 The Case Study of Frangipane School  
### General Description  
This examined school building was realized in the 1960s in the Southern side of the historical city centre of Reggio Calabria and designed according to a code of the first generation (Regio Decreto Legge 25 Marzo 1935, n. 640, [30]). The main class of use of adjacent buildings, also built up in the 1960s-70s can be classified as \"residential\" and \"commercial\", with a majority of multi-story RC structures with up to 4 or even 10 elevation levels from the foundation. Overall, the Frangipane school consists of 5 major parts with regular shapes, noted as \"Corpo A\" to \"Corpo E\" in Figure 4a.  
Among others, the attention of the present investigation is focused on the so-called \"Corpo A\", which is highlighted in Figure 4 and is currently used to host the majority of students during daily activities, with a major risk for occupants in case of a seismic event.  
The selected building portion is characterized by four elevation levels and covers approximately 470 m\({}^{2}\)/story, for a total of around 1870 m\({}^{2}\). M  
Figure 4: Frangipane School in Reggio Calabria: (**a**) top view and (**b**) front view (South side), with evidence (red box) of the area of retrofit intervention, and (**c**) outside view.  
current investigation, the \"Corpo A\" system is characterized by an independent structural behaviour from the rest of the school building, thanks to the presence (even not adequate) of a seismic joint at the interface with \"Corpo C\". The presently reported retrofit intervention, in this regard, also consisted of the increase of the seismic joint thickness (from about \(\approx\)3 cm of the original system up to 42 cm with the current intervention) in order to ensure the building system accommodates the lateral displacement of seismic devices and the cumulative effect of inter-story drift amplitudes for \"Corpo C\".  
The examined \"Corpo A\" sub-system is characterized by a mostly regular distribution of load-bearing members through the elevation. The building has a total height of 15.2 m, with an inter-story height of 3.8 m each (Figure 5a). The plan layout is characterized by a total dimension which covers a length of 47.2 m and a maximum width of 9.9 m. In terms of seismic retrofit purposes, it has to be noted that the system suffers from a high length-to-width ratio in the plan, and this aspect was taken into account in terms of possible sensitivity to torsional motions while choosing and detailing the intervention and the seismic devices as in Figure 3. As a minor extension, see Figures 4a and 5b, there is an additional portion of the sub-structure, on the North side, with plan dimensions of 7.1 \(\times\) 8 m, a total height of 15.2 m and an inter-story height of 3.8 m each.  
In total, for the longitudinal direction (\(x\)-direction) of the building system, a number of 13 frames is used to create the 3D structure. These frames are equally spaced at 3.86 m along the maximum size of the building system. The exception is represented by external frames (on the East and West sides of the building system), which are characterized by a maximum spacing of 4.15 m.  
In the transversal direction (\(y\)-direction), RC frames are reduced to 3 and irregularly spaced on the plan layout of the 3D volume, that is, with a spacing of 6.8 m, 2.7 m and 7 m, respectively. Note that the minimum space of 2.7 m follows the destination of use of indoor spaces and corresponds to the main corridor of the school. Inter-story and roof slabs, finally, are realized with 35 + 5 cm thick, unidirectional resisting cross-section, and oriented as reported in Figure 5b. Table 1 summarizes the cross-sectional dimensions of pillar and beam-type resisting RC members, grouped by the story, while additional selected geometric details are proposed in Figure 6.  
Figure 5: Frangipane School in Reggio Calabria: (**a**) vertical and (**b**) horizontal cross-sections (out-of-scale, with dimensions in m).