The work and the technique: "Stadio Olimpico" in Rome, Italy
Società Consortile Olimpico 90, in charge of the Stadio Olimpico expansion project, has also carried out a long series of operations, from coordination to execution, involving many companies in different parts of Italy. More generally, notable changes were made in terms of expansion, functional modifications, and major renovations of the existing structure, resulting in an almost totally rebuilt stadium.
The main innovation of these works lies in the stadium’s roof: a tensile structure, lightweight and of modern construction design, anchored to a huge steel ring that surrounds the entire Olimpico. This ring is mounted on 12 steel pillars and four reinforced concrete pillars, around which the stairwells are developed.
Work began on demolishing the pre-existing North curve in June 1988 and a month later on the South curve, using specially adapted machinery. When this was complete, construction began on the new foundations, built on large diameter piles and the precast and pre-stressed reinforced concrete pillars, such as the main beams and floors. Work subsequently moved on to the assembly of the steps, and to the construction of the stairs and the new emergency exits inside.
In July 1989 the dismantling of the existing Monte Mario grandstand also began.
At the same time, the steel sections of the outer ring and the metal columns were built in Taranto. These were designed to facilitate transport and assembly on site, where they were completed with the sandblasting and painting process.
Once at the construction site, the structures were lifted to a great height by a tower crane with a maximum capacity of 350 tons and two crawler cranes, one with a capacity of 400 and one with a capacity 600 tons. With scrupulous alignment control, they were leaned against the pillars and then fixed between them until the completion of the outer ring, which is composed of six sections.
After the ring's completion, the tensile roof structure was built, which is held by galvanised closed spiral-type load-bearing and stabilizing ropes, fixed to the rigid structures through the "cast head" system.
Finally, the gigantic cover sheet was assembled, made of a modern cotton that is composed of glass fibres covered with Teflon, for a total weight of 11,500 kilograms.
Changes to the project during construction, which had mandatory delivery times, required increased use of men and vehicles to complete the work, reaching peaks of 1,200 people at the construction site.
The stadium was completed in less than three years, and opened on 31 May 1990 in the presence of Pope John Paul II.