Sound barriers | Chiasso | 2002
A steel forest
Dipartimento del territorio
Architetto Mario Botta, Lugano (Collaborators Studio Botta: Danilo Soldini, Daniele Eisenhut)
Grignoli Muttoni Partner SA, Lugano
Consorzio protezioni foniche Chiasso - Officine Ghidoni SA - Ferriere Cattaneo SA - Officine Franzi SA - Tubosider SpA
The A2 highway existence in Chiasso area generates a huge environmental load due to the big number of vehicles passing through and particularly to the amount of trucks that often stop off for customs forms emission.
In order to increase the value of the area, as early as in the 90s, the Regional Department and Chiasso municipality decided to build sound barriers that represent an added value even from the architectural and urban point of view.
Supporting structure: through reinforced concrete skirting board
Mast structure: tubular sections linked by melted joint
Covering: semi-finished laminated glass, steel sectioned lattice
Side walls: laminated glasses and metal sound-absorbent elements
Redeveloped stretch length: 1.800 m
Steel structure weight 2.450 tons
Glass surface 32.000 sq m
Sound-absorbent surface 24.000 sq m
Lead time 26 months
The masted structures, geometrically aligned and made up of variable diameter steel section components that have melt steel branches and joints, have a 10.5 m longitudinal module.
The joints between the modules allow to adjust and flexibly adapt to the railing course. The glass wall of the mast’s crown is made up of VSG stratified glass. The side walls are made of VSG stratified glass plates and of sound-absorbent metal elements.
On the highway stretch running through Via Como, three modules can be distinguished. On the river side a unit of little masts, that have been directly assembled on the wing wall, rises. Between the North-South lane and Via Como there is a unit of huge masts supporting the whole covering. And another unit of little masts dividing the pavement from the street marks Via Como.
The detailed design and the significant modularity allowed to produce the components in a short time. Every element had been prepackaged in the workshop so as to make the most of the transport possibilities of the consortium firms, that were well located in proportion to the building site location.
The produced elements test, whether from the point of view of the materials or from the one of geometry, filled an essential role to attain a practically perfect geometry.
Then, in situ, EMPA executed some tests using Adrienne method, that consists in placing on one side a sound source and on the other side a receiver, that, in a range of frequencies, allows to determine the achieved insulation level.