Settimo Milanese – Milano (IT)
Bouygues E&S InTec Italia S.p.A.
SURFACE OF THE PROJECT :
About 2800 Sq. m
YEAR & AREA OF COMPETENCE :
2019 – 2020 | CIVIL – INDUSTRIAL
AIM OF THE PROJECT :
Construction of a new Data Center, named “ML5.1”, for the company Equinix . The project is part of the development of the technological hub outlined within the “Castelletto Uno” Implementation Plan in the Municipality of Settimo Milanese. “ML5.12 hosts spaces intended for the storage and processing of computer data and therefore consists, for the most part, of areas intended for computer equipment (servers) and technical rooms necessary for their operation as well as for the operation of the building itself.
The building consists of a single body of 3 floors above ground with a footprint of about 2.770 square meters; on the ground floor there are also various external technical areas and, on the roof , some technical rooms.
The structural intervention included the construction of the reinforced concrete foundations, the sub-foundations for the reinforcement of the ground made with reinforced helical poles (CFA), the supporting structures in elevation of the prefabricated reinforced concrete building, integrated by stairwells and bracing cores in reinforced concrete cast in place.
ATTIVITÀ SCL :
Executive structural design (Law 1086/71), Seismic Deposit and construction design of the reinforced concrete works relating to the main building and the steel works relating to the secondary structures (technical rooms, system support frames, pipe rack, external security staircase, platform roof). The project of the bracing cores in reinforced concrete was carried out in low ductility.
During the construction phase – on behalf of Bouygues – coordination with the Client, the Work management, the designers of the specialized disciplines and the suppliers, regarding the structural construction project, with particular reference to the requirements of the anti-seismic design according to DM 17 / 01/2018.
The building is characterized by spans of about 10 m and inter-floor heights of 6 m; the average loads per floor exceed 1000 kg / m2, the reference period for the life of the building is 75 years (use class 3).
The foundations are made of plinths in correspondence with the prefabricated pillars, slabs in correspondence with the reinforced concrete partitions and a beam timber frame connecting with an interposed slab to support the ground floor. The foundations are indirect, supported by bored piles of different diameters and lengths in relation to the required capacity.
The design of the elevated structures and the foundations is carried out with different three-dimensional models, which represent the actual distributions in terms of mass, stiffness and strength; the characteristics of constraint and stiffness of each model are defined in order to maximize the stresses on the elements considered (piles, foundation slabs, prefabricated pillars, cuts walls cast in situ).
In details, the seismic design of the cuts walls is carried out according to the concept of low ductility. For the squat walls the inclined shear reinforcements required by the NTC-18 have been prearranged. In order not to congest the reinforcement, the amount of bars was calculated in relation to the traction present at the base of the wall most stressed in shear.
In order to achieve this result, it has been studied a flat FEM model with SHELL elements supporting the vertical load and the shear action at the various levels obtained from the 3D model of the building, for the maximum SLV seismic case.
From the diagram of the maximum stresses of the material, through integration on the stress curves, the inclined reinforcement absorbing the action in the local X direction have been defined.
Construction assistance activities:
– coordination with the Works Management for all the structural issues;
– development of the projects related to the seismic connections of secondary structures and equipment;
– examination and evaluation of the structural technical solutions proposed by the construction companies /suppliers in order to verify the specifications required by the Client and the respect of the constraints and performances to be guaranteed;
– verification of conformity and completeness of the construction projects performed by the suppliers (drawings, documents and quality checks provided by the manufacturer).