Structural Maintenance of the Tension Structure Roof - Rome Olympic Stadium

The roof of the Rome Olympic Stadium, built in the 1990, is one of the first examples of roof with tension ring, radial tension structures and external compression ring, for the covering of the stands of a stadium, a scheme that since then has spread in many recent applications. In 20 years of structural monitoring and maintenance it has been possible to compare the design assumptions with the actual behaviour. The global pre-stressing and geometry has been monitored in the time and some re-tensioning work have been carried out after the natural long term creep of the steel cables. The behaviour and the operations have been followed and simulated on numerical models. In 20 years time also the degradation of some secondary members have been detected and the maintenance, replacement and improvement works are carried out. This experience, while confirming some design decision, can provide interesting indications for the design and planning of this type of construction.