Multi-story building with hybrid timber-steel structure in São Paulo

Hybrid systems, mid-rise mass timber, XLAM

HYBRID STRUCTURES… WHY?

In this case, we were commissioned to carry out the preliminary design of an 11-story building in São Paulo, Brazil, with a hybrid timber-steel structure.
The choice of the structural scheme was conceived based on the constraints of Brazilian fire safety regulations, which do not permit the use of timber structures for stairwells and elevator shafts in buildings of this height.
We decided to analyze the option of a dry core with steel structures as an alternative to reinforced concrete.
The use of steel frames is consistent with the prefabrication of timber structures and allows for significantly reduced construction times.
Steel also provides greater control over errors and construction site precision.
We designed 3-story 3D steel frames with the possibility of welding the frames of subsequent floors progressively.
The system proved to be very interesting in terms of cost/benefit analysis.

BUILDING DESCRIPTION

The building covers a floor area of approximately 380 m².
The floor plan of the building is reduced on upper levels, with 8 floors having an area of 285 m².
The top 2 floors serve a technical function for the building and have a reduced area of 50 m².
The total area of the project is approximately 2,760 m².
The building has an overall height of 32.6 m.

STRUCTURAL SCHEME

The structural scheme of the building is conceived as a hybrid timber-steel system.
The stairwell-elevator shaft serves as a steel bracing core to resist horizontal forces due to wind.
The core is dimensioned to ensure a maximum displacement at the top equal to H/1800. This limit is particularly stringent but was imposed by the client.
The bracing system is complemented by a glulam timber frame to support the vertical loads from the floors.
Multi-span floors in Cross Laminated Timber with a thickness of 160 mm and 5 layers.