The main pillars reconstruction of the Basilica di Collemaggio

The Basilica of Collemaggio in L’Aquila, built in the late of XIII century by the will of pope Celestine V, experienced several seismic events during its life that caused some damages to its masonry structures. Particularly, the April 6th, 2009 earthquake caused the failure of the transept area where the dome, the barrel vaults, the triumphal arch with the above supported wall, the two main pillars and the roof structures collapsed. In this paper, the reconstruction project of the two main pillars, characterized by an inner hollow reinforced concrete column covered with the former outer layer of stone blocks recovered from the collapsed main pillars, together with the new relative foundation system is presented. After a brief description of the conceptual design on which the seismic retrofitting intervention was based, different type of numerical analyses are reported. Finally, a short description of the construction stages during their realization is presented.