Berlusconi Attends Groundbreaking Ceremony of Base Tunnel on Bologna-Florence Motorway - it/21Italian Premier Silvio Berlusconi and minister for infrastructure and transport Pietro Lunardi inaugurated on 7th March, 2004 the opening of the base tunnel worksite in Pian del Voglio, on the Bologna-Florence motorway dualling. The 8.6 km twin bore tunnel through the Apennines features a finished cross section of 140 sq m. It will link Badia Nuova in Emily Romagna with the Poggiolino interchange in south Tuscany and is part of a 11.2 km section including a short tunnel, 250 m in length, and two twin viaducts. Tunnelling of the short tunnel is to start in June. Completion is expected in January 2009.Excavation of the base tunnel will commence in December. The base tunnel will be driven from four drives, two on the Bologna side and two on the Florence side. A 4 km pilot tunnel on the Bologna side was finished in 2000 to investigate the geology. The ground on that side will consist of soft ground and harder rock, requiring to employ a hydraulic hammer in the soft ground and the drill/blast method in the rock. On the Florence side, the ground is expected to be tender clayey terrain in majority. Four jumbo drill rigs will be used, one on each drive. The contractor Risalto, a consortium of Rizzani de Eccher, Salini and Todini, plans to acquire four new machines.The supplier has not been chosen yet. Dumper trucks will be used for the mucking-out. There will be 24 emergency lay-bys in the tunnel, one every 900 m, 122 safety niches, nine cross vehicular passages and nine pedestrian cross passages and state-of-the-art safety and ventilation systems. Click it/21. Visit www.autostrade.it, www.rde.it, www.salini.it and www.todini.it 16/04.