Work is due to start imminently on the second drive of the 2.2km long Bronzolo to Bolzano road tunnel in the Alto Adige region of Northern Italy.
Contractor, Societa’ Italiana Per Condotte D’Acqua is constructing the tunnel using drill and blast from two faces. Each drive is 1km long from two portals at opposite ends of the tunnel with each drive working towards each other.The first started from the Pineta di Laives portal in February this year and has progressed 150m with an advance of 5-6m a day.
The geological conditions of the area comprise porphyry making profiling of the 12m wide x 9m high tunnel very difficult. For this reason the contractor chose to use two computerised jumbos, the Sandvik Tamrock Jumbo Axera T12. A spokesman told T&TI that the 130 holes of the drilling pattern is completed in 1.5 hours. The drilling data is stored in a computerised data logging system where it can be analysed by the project management.
The contractor was awarded the job by client ANAS (the road authority) in June 2000 with a completion date set for November 11, 2002. Costs were unavailable.
The single tube, twin lane tunnel will connect the statel road SS12 between Bronzolo and Bolzano.
The same contractor is currently constructing a 1.2km long, 12m wide x 9m high tunnel on the Val D’Ega statal road for the same client. Due to similar ground conditions it is using a computerised Tamrock Data Jumbo and has progressed 160m since January 2001. The project is scheduled for completion in December 2002.
