Seismic damage and performance of Palazzo Centi after L’Aquila earthquake: A paradigmatic case study of effectiveness of mechanical steel ties

• The behaviour of a historic building damaged during the 2009 L’Aquila earthquake is examined.
• The seismic damage suffered by L’Aquila masonry buildings is illustrated.
• The effectiveness of mechanical tightening (steel ties) is quantified and discussed.
• Limit analysis is performed for evaluating both in-plane and out-of-plane seismic capacities of façade.

This paper concerns the seismic response of Palazzo Centi after the 2009 L’Aquila earthquake. Built in the second half of XVIII century, Palazzo Centi is a three-storied building characterized by a rectangular plan with a central court. The vertical structural system is made of masonry walls arranged in plan to form a regular mesh.After the 2009 L’Aquila earthquake the building showed a widespread damage occurred in the vertical masonry structures with more intensity at upper storeys; there were also damages to non-structural parts: light masonry and fake vaults. The building case study is a paradigmatic example because during the 2009 earthquake, differently from other historical masonry buildings, it responded “reasonably” well in the main structural parts. The seismic behaviour was analyzed thoroughly in order to investigate the effectiveness of the, initially unknown, recent retrofit interventions carried out in 2003. These mechanical interventions proved to be the reason of the good seismic behaviour of the building and that “saved” it from more serious damages.On the basis of the data acquired by the authors during the post-earthquake reconnaissance activities and from the structural analyzes results, in conclusion, the case study of Palazzo Centi demonstrated to represent a clear example of the effectiveness of the traditional techniques in designing and retrofitting of masonry buildings.