The paper illustrates the works, materials, and results of the design for the full seismic retrofitting of a heritage-protected building, located in the historic center of Sulmona, currently home to the "Ovidio" High School and the "Municipal Library". The building was built in the 17th century and over the centuries it has been subjected to numerous reorganization and renovation interventions. Its current appearance derives from the significant and radical renovation that took place around 1925-1930, following the 1915 earthquake, and can be traced back to the architectural taste of the time, which can be labeled as "eclectic" with neoclassical and/or neo-renaissance references.

Approach

The redevelopment project, considering the safety requirements related to the use of the building as a school building, provides for not reducing the nominal life of the construction and for carrying out the safety assessments with the same rules as for a newly built building. The greatest criticality of the seismic resistance of the building is determined by the insufficient mechanical characteristics of the original materials in place. The total or partial lack of diaphragm behavior of the floors and the absence or insufficiency of the connections between the masonry walls and between the decks and walls also contribute to the seismic inadequacy of the building. These conditions compromise the optimal box-like behavior of the building and also determine torsional effects in the dynamic response of the building, with a further reduction in the seismic-resistant capacity. On the basis of these observations, the design strategy has primarily provided for the increase of the mechanical characteristics of the masonry and the elimination of critical issues.

Results

To achieve the objective, multiple synergistic interventions are planned: closing niches and openings by indenting; consolidation of walls with mortar injections, repointing and transverse connection of the facings; insertion of new masonry walls; insertion of top steel curbs; in-plane stiffening of floors and connection with walls; connections of angles and hammers of masonry walls; strengthening openings in the load-bearing walls with perimeter steel profiles; thickening of thin walls and "under windows"; strengthening of r/c beams with metal profiles; insertion of tie rods; strengthening of partitions with anti-tilting nets and metal profiles. The adopted interventions, while compatible with the protection of the historical and architectural value of the construction, allowed to upgrade its seismic safety level to that of a newly built building.