The excavation of the Santa Lucia tunnel (7734 m) has just been completed for the A1-Variante di Valico highway between Bologna and Florence.
The EPB TBM manufactured by Herrenknecht with a final diameter of 15.87 m and a total weight of approximately 4800 ton is the largest in Europe, which Pavimental S.P.A used for the excavation.
The work of the tunnel is part of the extension project of the third lane Barberino di Mugello – Incisa Valdarno in Barberino di Mugello – Firenze Nord along the A1 Milan – Naples Highway.
The new Santa Lucia Tunnel is constituted by a single bore, the naturally excavated part of which begins at marker 3+423.00 and ends at marker 19+971.00, covering a total distance of 7,548 metres; considering the covered stretch as well, which includes the artificial tunnels, this starts at marker 3+395.73.00 and ends at marker 11+120.0, covering a total distance of 7,724.27 metres.
The platform is constituted by three lanes 3.75 m wide and two verges 0.70 m wide. The marginal element on the left is constituted by a redirecting profile and on the right by a non-surmountable pavement with a minimum width of 60 cm, so as to constitute a protected route for exiting vehicles in the event of faults.
The Tunnel will be constructed with the help of an earth pressure balance shielded tunnel boring machine called TBM – EPB.
MCT Italy has supported Pavimental with the production of Tunnel Segment in a dedicated factory. The ring is made with 9 segments and each of them is one of the biggest ever produced in Europe:
- 5,5 meter length
- 2,2 meter width
- 55 cm thickness
- 16 ton weight
- 15 minutes cycle time