THE MONUMENTAL COMPLEX OF SAN MICHELE

   

The building is an important part of the monumental complex of the former Institute of San Michele in Ripa, built from the XVII century for the willing of pope Innocenzo XII. His willwas, trough this institution, to solve the enormous problems of mendicancy and vagrancy in Rome, with the creation of an organic plan focused on the reeducation of young men and women throughout a professional training. The monumental complex is important not just as architectural heritage (it contains the Great Church and the Juvenile Detention Center by the architect Carlo Fontana), but it also has social value because it anticipates a modern mentality that considers the prisoner as a recoverable individual. The complex’s construction history is 150 years long, and, since it was the location for artisanal activities as well as recover site, it has a great extension and a fragmented plan, in contrast with a rhythmic and unitary fa.ade toward the Lungotevere. In the ‘80s, when, after being abandoned, his structural status was way above the limit state of collapse, the complex of San Michele was object of an important restoration intervention in order to be converted into the new headquarter of the Ministry of Heritage and Cultural Activities. The radical intervention included the substitution of almost all roofs and wood ceilings, the consolidation of vertical structures and vaults with ignition of fluid cement mortar and epoxy resins, the consolidation of structural failures of foundations due to the proximity of the Tevere river, the refurbishment of mortars and flooring of porticos and loggias, the construction of new security staircases and fire escapes.
The Female Prison was designed by the architect Ferdinando Fuga in the 1734 in an area that faces the piazza of Porta Portese. The plan has a development mostly longitudinal but in section is articulated in three big volumes: the lower volume is constituted by the basement, the first and mezzanine floor; the volume of the cells and the major floor-toceiling hall; the attic level.
The recent restoration project was basically a consolidation project, that helps the new functional configuration of the interiors, eliminating or overcoming architectural barriers and the seismic retrofitting the structure. The conservation project preserves the skin of the building and its global structural behavior. This was possible with a series of local interventions, in accordance to the previous restoration works of the ‘80s, so that the global structural behavior would not change.
The interesting spatial features of this building, such as the former prison’s cells, were preserved and renovated as new small office rooms. A new compound beam has been placed so that it could transfer the loads on the same supporting walls of the original arches, whose loads would not stress the walls anymore. In this way, the cell’s walls tend to assume the only function of simple partition walls. This intervention, together with other consolidation interventions of the masonries, contributes to the seismic retrofitting of the building.
For what it concerns the rooms on the mezzanine floor, these were at different levels, so accessibility was difficult. The metal structures of ceilings were cut and moved to the same height so that the whole level could become fully accessible. This approach is interesting because it preserves the structures that were constructed with the ‘80s intervention. It is also sustainable because it avoids a possible removal intervention and a transport to a garbage dump. For the vaults of the mezzanine floor, the project performed the removal of the consolidation from the previous restoration, that consisted in a reinforced concrete deck realized at the extrados of the vault, which was considered inadequate for its excessive weight overloading the structure. Another consolidation work is the construction of new strengthening reinforced ribs, by pouring fibro-reinforced mortar, that is delimited by the juxtaposition of formwork made of alveolar concrete. In addition, to guarantee an efficient collaboration between the false ribs and the existing mural section, frayed-edges aramid fiber rod were inserted in both of the extremities of the pour. In some cases after the removal of the concrete deck, important tie rods, often made by ropes, were found and integrated with the new design. The aramid fiber was also used in form of tape for the consolidation of wood lintel located over the windows of the attic level and in the masonry pillars. Wood lintel were cleaned and treated with a protective solution, then a tape of aramid fiber were applied under the wood elements and joined with the above wall.
This intervention increased the flexional rigidity of the wood elements. In the case of the masonry pillars the tapes were vertically glued to the wall and then fastened to the below masonry trough the use of rod of aramid fiber, frayed at edges and turned over the tape.
Last, the intervention of consolidation of the roof regarded the placement of new additional beams and the reinforcement of the existing ones to increase the bearing of loads, accomplished by welding strengthening plates to the beam’s bottom flange and web in order to improve respectively its mechanical characteristics and its stability.

[by Alessandro Bozzetti, text Alessandra Ledda]