Work proceeding on 75 km of difficult tunnels. August 1999.
Tunnelling commenced October, 1996 and is due for completion end-2002. Seven running tunnels are involved as follows, from Bologna to Firenze: Pianoro (10.7 km), Sadurano (3.77 km), Monte Bibele (9.1 km), Raticosa (10.39 km), Scheggianico (3.54 km), Firenzuola (15.06 km), and Vaglia (18.35 km). Also 12 access tunnels total length 8.8 km are required to split the route into sections of not more than 3.5 km.
Main contractor Cavet reports 20 km of 71 km alignment has been excavated to date, 60 % of which has also been fully lined. Some 32 x 130 m² faces open at present. The access tunnels are generally 60 m² with 14 % maximum gradient, and 2.4 km have been fully lined on Raticosa tunnel due to poor ground conditions. North portal of Firenzuola at San Pellegrino is being driven at 21 m wide for 600 m to accommodate siding for spare train. All equipment used in these tunnels is flameproofed. October 1999.
Boring of 6.5 km Vaglia segmentally-lined service tunnel to commence in June using Wirth double telescopic shield TBM from a quarry near the Firenze end of the proposed 18 km-long main tunnel. Geology is marly limestones and lime marls with marly strata. Contract also includes 2.7 km of access adits. The northernmost 7.5 km of Vaglia running tunnel was completed a year ago, and completion is now scheduled for 2005. Visit www.wirth-drilling.com May 2000.Restricted tendering for construction of section of 9.243 km Monte Bibele tunnel, deadline 1st August, 2000. Contact Cavet, fax +39 051 651 8327 and visit www.rocksoil.com July 2000.
Tunnel advance on 32 faces currently averaging 1.6 km/month with less than 5 % variation from budgeted cost. Crown excavation and lining of 728 m-long San Pellegrino chamber at the north end of Firenzuola tunnel nearly completed at 2-3 m/day average advance. Final design of 18 km-long Vaglia tunnel at south end of alignment includes 9.26 km-long x 5.6 m i.d. service tunnel to be driven using double telescopic shield Wirth TBM type 630 E/TS erecting 250 mm-thick trapezoidal reinforced concrete segmental lining. This will run parallel to main tunnel for 6.5 km, with connections at 250 m intervals. Main tunnel currently underway from Carlone access and north portal at 7 m/day of finished tunnel in marly limestones and lime marls with marly strata. Visit www.rocksoil.com and www.wirth-drilling.com July 2000.