Office building in Lyon

Building use

Office building

Country/Region

France

Overview

The tower Silex2 stems from the renovation of the precedent EDF tower. The previous building from the 70’s has be completely stripped down to its concrete structure. The top 4 floor were demolished and re-built. Connected to this, a new slender tower was built, so to extend the floor plate of the old building to new requirements, adding about 400 square meters per each floor. The new tower is structurally independent and, unlike the all-concrete old tower, this is entirely made of steel. The new tower has an externa skeleton, so that the internal spaces are completely freed of any obstruction as it relies on the vertical transportation of the old tower to which it is functionally connected.

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

Construction date: 2018-2021
Number of stories: 23
Gross floor area: 25,000m2 pre existent building + 9,200m2 new structure
Adopted design code: –
Engineer(s): Idom. Terrell Group + Smb Constructions Métalliques
Contractor(s): Builders & Partners

Issue and/or innovation

The short span of the building is 12,2m and in order to achieve the maximum penetration of daylight and to reduce the floor sway.

Reason for composite solution

The composite floor solution was adopted to reduce the floor vibration and to minimize the structural height of the floor assembly itself, in order to maximize the transparency and penetration of natural light.

Specific solution/technical details

The floor system of new tower measures 11 meters of clear span by 36 in length. It is composed of I beams that act compositely with the concrete layer by means of a double row of shear studs. The I beams are perforated in order to allow the penetration of MEP and ventilation ducts, so as to minimize the depth of the false ceiling.