The intervention project includes renovation and expansion of an existing building. The existing structure is made of tuff stone walls and ceilings with thickness varying with the type of steel beams and pots vibrated concrete (or tuff blocks).
The intervention in project involves the replacement of some existing floors, in addition to the insertion of n ° 2 additional intermediate floors (for a total of n ° 5 and n ° 4 floors horizontal elements within the pre-existing masonry box) and the insertion of new stairwells and elevator shafts (with reinforced concrete partitions). It is also expected an enlargement in superelevation, with the realization of an additional floor (the fifth).
The newly constructed intermediate floors are provided quality mixed-polystyrene concrete, the proper functioning seismic as content weight. The additional floor (the fifth) in elevation is provided with framed structure of reinforced concrete.
The analysis was performed by modeling the building, in the software, the walls as masonry walls and assuming the hypothesis of rigid planes: the decks, in fact, consist of floor slabs with concrete topping of 5 cm (including the ground floor, on which sometimes the coverage is scheduled for a 5 cm reinforced hood attached to the walls). As required by the NTC 2008 for the mixed structures (in this case wall structures for the bottom of the existing, and reinforced concrete structure for the plan in elevation) or horizontal actions for each level, were assigned to the same structural technology: in this case, the reinforced concrete (RC walls for the first four floors, frame in ca for the fifth floor).
They will also be taken suitable measures and design choices, such as using lightweight floors of mixed-polystyrene concrete (as mentioned, the smooth functioning of earthquake-proof because of its own weight) and curbs a.c. the level of hedging decks (in order to better spread the load on the walls, especially those deriving from the fifth floor pillars).
All verifications to NTC 2008 have given positive results, however, out calculation in order to further improve the level of security (under the structural aspect) it is believed of having to use for only in isolated pillars of masonry, reinforced with a composite material carbon fiber (CFRP).
This intervention fact guarantees, an increase of 5% of the normal stress resistant. It therefore provides a discontinuous bandage (CFRP bands of width 20 cm, spaced apart by 20 cm) for the whole height of the isolated masonry pillars.