Giant Sparvo EPBM completes first driveAug 2012
Herrenknecht News Release
The world's record-setting Herrenknecht EPBM has completed the first bore of the 2.5km long twin tube Sparvo tunnel on the new highway route between Bologna and Florence in Italy. Under construction since August 2011, the giant 15.615m o.d. TBM required just less than 12 months to complete the 2,413m two-lane road tunnel.
Management members celebrate the achievement
The first tube at Sparvo completed
Excavation of the twin tube tunnel at Sparvo is regarded as the most demanding part of the overall project, not only on account of its sheer size but also because of the prevailing geological conditions. The geology on the tunnel alignment comprises mainly clay, claystone, sandstone and limestone. In order to achieve the requisite safety and speed during construction, the Italian client opted to use mechanized tunnelling technology. To this aim, Toto Costruzioni Generali SpA commissioned Herrenknecht AG to build the needed EPBM in 2010.
Toto is the leading partner in a joint venture that includes Vianini Lavori SpA and Profacta SpA. At the first tube breakthrough, Toto reported a top advance rate of 22m/day, building rings of 2m wide precast concrete segments, and confirmed the superiority of mechanized tunnelling when compared to conventional technology. This process involved the removal of 4,215m3 of soil, which presented a major challenge for site management.
Assembly of the huge TBM at the job site
15.615m diameter, the cutterhead and TBM ready to start the task
Over the next few months, and after completing the first drive at the end of July, TBM Martina will be turned around to excavate the second tube on its 20m parallel alignment. The client Autostrade per l'Italia SpA anticipates the tunnel opening in mid-2013.
"This machine was intended to set new standards, including with regard to its features for particularly gaseous soil," explained Herrenknecht Project Manager Alexander Ell. Hand in hand with Toto and with the support of the local authorities, and the Universities of Bologna and Turin, Herrenknecht developed a complex safety system which includes explosion-protected equipment, a fully-enclosed conveyor belt, a permanent fresh air supply to all areas of the machine as well as permanent monitoring of gas concentrations. "The concentration of methane at the tunnel face was so high that fresh air had to be transported to the excavation chamber over longer periods of time," reported Ell. "So far, our new system has worked just the way we have anticipated," he added with satisfaction.
"With the world's largest TBM, we have become accustomed to setting new records, two of which are this machine's size and its advance rate," explained Alfonso Toto, CEO and Managing Director of project JV and tunnelling lead partner Toto Costruzioni Generali, during the first breakthrough celebrations.
As a leading manufacturer of mechanized tunnelling and shaft sinking equipment, the Herrenknecht Group achieved a total operating performance of €1,104 million in 2011, supplying 65 tunnel boring machines for road tunnels alone in the year. All in all, Herrenknecht equipment has completed 1,900km of tunnels in diameters of more than 4.2m since its establishment in 1977. The Herrenknecht Group employs about 4,000 people worldwide and has trained more than 240 young people. With 77 subsidiaries and associated companies in Germany and abroad, Herrenknecht offers comprehensive services tailored to the respective project and contractor.
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