SVILUPPI NELLA SPERIMENTAZIONE DELLA TECNICA DELL’“ARCO ARMATO”

Lorenzo Jurina1, Maurizio Giglio2, Sara Bonfigliuoli3

1 Politecnico di Milano- dip. ABC, lorenzo.jurina@polimi.it

2 Architetto libero professionista, Milano

3 Architetto libero professionista, Monza Brianza

ABSTRACT

In the consolidation of masonry arches and vaults the best design choice is the one that allow to obtain a compression behaviour between the masonry blocks, possibly without changing the actual geometry and limiting the addition of mass. Structural solutions that are effective and, at the same time, compatible with the historical material are therefore to be preferred to invasive solutions, that sometimes could even be harmful. Among the various possibility, the so called "RAM - Reinforced Arch Method" can be applied. This technique consists in changing the loads on the structure, adapting them to the existing geometry, through the placement and the post-tensioning of steel cables, either at the extrados of the arch or at the intrados. RAM is a reversible, active system that has been widely tested and used as reinforcement with respect to vertical loads. Recent developments of the method are oriented to verify the effectiveness of this system also against horizontal actions, such as seismic ones. In this paper the results of a recent experimental campaign conducted on about 500 small scale physical models of arches are discussed. The specimens simulate several arches having different geometries, subjected to horizontal loads and "consolidated" with RAM, under different tensions applied to the consolidation cables.

Some recent and innovative applications of this technique are illustrated, such as the elliptical dome of the church of Santa Caterina in Lucca and the ruins of the Armenian Sanctuary of S.Amenaprgitch in Ani (Turkey).

Parole chiave/Key-words:

Reinforced Arch Method, Compatibility, Reversibility, Seismic loads