A6 Turin–Savona Motorway S.p.A. Duplication of the Rivere–Montecala section and upgrading works on State Road 28 bis (Lot 15).

Project objective

As part of the duplication of the Turin–Savona motorway carriageway (Lot 15, Rivere–Montecala section), the intervention included the new northbound carriageway, the tie-in to the southbound carriageway, the new interchange and the Millesimo bypass (SV).
Our Company delivered the executive and construction design of the entire alignment, including underground works, viaducts, retaining works and overpassing structures.

Main works

Motorway duplication carriageway

Natural tunnel “Vespe”
Approx. 340 m long, with overburden between 5 m and 30 m. Excavation by half-section with subsequent benching and final lining. Stress–strain analysis using FLAC 2D for defining pre-support and lining typologies.

“Bormida di Millesimo Nord” viaduct
Length 410 m, maximum span 115 m, prestressed reinforced-concrete variable-depth box-girder deck (Dywidag type). Caisson foundations and jet grouting for soil consolidation and waterproofing.

Cut-and-cover tunnel “Tiro a Segno”
Box structure 85.45 m long with reinforced-concrete slabs and walls, thickness up to 1.2 m. Founded on rock substrate at 8 m depth.

Millesimo bypass

Natural tunnel “S. Sebastiano”
Length 110 m, winding alignment, overburden 5–30 m.

“Bormida di Millesimo circonvallazione” viaduct
Length 235 m, prestressed reinforced-concrete deck (Dywidag type).

Cut-and-cover tunnels “Millesimo 1” and “Millesimo 2”
Lengths 383 m and 112 m, reinforced-concrete box structures with precast elements and retaining walls with two-level anchors.