Design, construction and installation of the Spire located in the Unicredit skyscraper of Porta Nuova in Milan.
SCT INFORMATICA, in the role of Project Manager together with other companies, has directed and followed the process of creating the “SPIRE”.
The spire (Spire), 80 m high and 8.8 m at the base, is located at the top of the Porta Nuova tower in Milan, at an altitude of 140 m above street level. 140 tons of steel were used for its construction and it is characterized by some complex structural features:
- Slenderness of the tower: to adapt to the architectural design, the load-bearing structure is particularly slender. Compliance with the prescribed deformations was particularly onerous.
- Shape: the tapered cylindrical “open spiral” shape is defined by the external cladding consisting of curved surfaces of varying diameters and dimensions, with consequent difficulties in the development and sizing of the support barracks and in the evaluation of the wind forces acting on them.
- Surfaces: the cladding, about 1200 m2, is made up of 10% glass, 90% of pre-perforated sheets and 50% of stainless steel. In the construction details, particular attention was given to the thermal effects, the assembly method and the maintenance procedures.
- Anchoring to the building: for the transmission of high loads (of the order of 4000 kN) to the columns of the building, the anchoring abutments of the spire involved the last 9 floors, in order to distribute the vertical tearing loads, contrasted sole weight of the insoles.
To define the sizing conditions, a test campaign was carried out in the Wind Tunnel of the Politecnico di Milano and local tests were carried out on the sheets at the CNR / ITC of San Giuliano Milanese. In addition, due to the height of the structure and the typical isolated tip shape, it was necessary to provide for a study with detailed tests at the Cesi of the lightning risk assessment according to current regulations and the measures to be taken for lightning protection.
SCT informatica managed, together with the group’s partners, all the construction phases: from feasibility to economic proposal, from design and structural calculation to implementation by helicopter.