Ex Varesine Area Developement, Milan

The development consists in a wide basement area on which are raised 12 buildings and a commercial zone.
The two major towers rise 150 and 137 m above the street level, and cross a four story basement 17 m deep.
A “podium” for commercial use and other minor buildings surround the bases of the towers.
Three high-rise buildings and six villa buildings, residential part of the development; one high-rise and two medium height buildings are instead dedicated to office space.
All the buildings  are supported by a common 300 by 105 foundation raft placed at fourth basement  and cast over deep piles and diaphragms.

Especially three high-rise buildings and nine minor buildings, based on concrete structures, are the residential part of the development. One high-rise (steel structure) called Diamond Tower and two medium height buildings are instead dedicated to office space.

The residential towers required a complete re-design of the floors structural system, and a general check and development of the structural design.

The higher tower- “Solaria”- features a trilobe plan with a triangular core and will be used for dwellings; the lobes have different heights. Besides large cantilevering balconies are distributed on the facades. The core, the columns, the floor and balcony slabs are in concrete; un-bonded post-tension is used in the horizontal structure.

Some specific structural problems had to be solved before the construction, taking into account the very strict constraints given to the structure by the architectural design approved by the Municipality of Milano:

- column shortening effects had to be studied and included in the design;

- the differential thermal movements of the balconies and the mega frame were allowed by using special retaining devices;

- the immediate and long term deflections of the balconies were limited by the use of post-tensioning;

- the dynamics of the slabs was studied and a full scale test is being planned in order to decide the use of specially designed tuned mass dampers to limit the accelerations and the displacements;

- high performance concretes (up to 85 MPa) have been used, leading to specific studies for acceptance, mix design, structural behavior.

The lower tower (30 levels) -“Diamond”- is supported by steel columns and composite (concrete and steel) floor structures; the central core is in reinforced concrete. The outer columns of the first nine floors are leaning towards the central part of the building while in the remaining ones up to the thirty-first level the inclination is reversed; at the transition floor the deviation of the axial load is counteracted by ties anchored in the core.

Useful links related to the project:

URBAN FILE - PICTURES FROM VARESINE
SOLARIA TOWER