Office building in Turin

Building use

Office building

Country/Region

Italy

Overview

The building is the new headquarter of the Intesa San Paolo bank, resulting from the merge of Intesa and San Paolo banks. The building is designed by Renzo Piano as an icon for the city of Turin, marking the legacy of the bank to the city. It hosts the main activities of the bank, offering over 100.000 square meters of office space with a large suspended auditorium and a public bar and greenhouse at the top of the tower.

Basic information (construction date, number of stories, gross floor area, adopted design code, engineer(s), Contractor(s), etc.)

Construction date: 2010-2015
Number of stories: 38
Gross floor area: 107,500m2
Adopted design code: Eurocode
Engineer(s): Expedition Engineering / Studio Ossola / Massimo Majowiecki
Contractor(s): Rizzani de Eccher, Implenia

Issue and/or innovation

The architect decision to have an auditorium on the bottom part of the building, suspended above the lobby and plaza caused the bottom part of the building to be column-free except for 6 large composite mega columns and an offset concrete core.

Reason for composite solution

The composite solution was adopted to carry the vertical and lateral forces acting on the tower, while respecting Piano’s aspiration for a slim and de-materialized structure. The need for a composite solution is due to the large loads acting on the columns, as they carry the weight and lateral forces acting on all the 36 floors of the tower. In particular, the forces acting on the internal columns is transferred to the perimetral mega columns by means of two large trusses that weight over 2000t each.

Specific solution/technical details

The 6 composite mega columns are thus composed of two curved steel blades that hide the column itself. The column is composed by S355 and S460 steel plates connected to the concrete by means of shear connectors. The plates form a square hollow section and concrete is poured on both faces, so that the composite action is fully exploited on both sides. The external curved steel profiles enclose the whole system, and they are connected too by means of shear studs with the concrete pour. The six mega columns are spaced 16,5 one from the other. The external curved profiles have a thickness of 30mm and are curved with a radius of almost 2 meters and they are spaced with 30mm thick plates creating and hollow square in the center. Each mega column has a total footprint of 2.805×1.968 mm. The steel plates inside the external curved elements have a thickness of 100mm and are further reinforced on the shorter direction with an additional plate of 50mm on each side, for a total of 200mm of steel. From the 7th floor above grade (after the huge transfer beams) the internal plates decrease in size, transforming in a X shaped reinforcement with a decreasing thickness from 100mm to 25mm at the top of the building.

Impact or effectiveness

The tower uses a total of about 91,000 m³ of concrete and 38,000 tons of steel. The six megacolumns are built with aboput 3200t of S355 and S460 steel, with the higher grade used in the lower portion of the tower. The section of the steel profiles decreases as the height of the tower increases.

References / Technical Papers Content

Carpinteri A., Lacidogna G., Cammarano S., Structural analysis of high-rise buildings under horizontal loads: A study on the Intesa Sanpaolo Tower in Turin, Engineering Structures, Volume 56, 2013, Pages 1362-1371, ISSN 0141-0296, https://doi.org/10.1016/j.engstruct.2013.07.009.