Excavation is due to commence this month on the Mavi (“Blue”) tunnel project in Turkey using the double shield, back-up and equipment supplied by Seli.
The 4.88m diameter TBM is to bore a 17,061m length of the water transfer tunnel for contractor Ilci Construction. The US$11.4M contract was awarded in October 2007.
Geology along the alignment comprises limestone and sandstone.
Fitted with 17” cutterhead discs, the shield has been designed with a maximum thrust of 8,544kN and drive power of 1,890kW (6 x 315kW). The cutterhead speed is up to 10.9rpm.
The TBM-driven section of tunnel will be lined with hexagonal precast concrete, each 1.3m long ring consisting of four segments of 250mm thickness. Seli has supplied the segment moulds as well as other equipment.
In addition, to deliver the complete equipment package for the contract, the manufacturer has also supplied the spoil removal transport. The trains have been designed to enable the TBM to advance by 4m per hour – or approximately three rings – at the maximum distance of the machine from the portal.
Seli said that the TBM section of the Mavi tunnel is scheduled for completion around the end of 2010. Tunnel construction includes a further stretch of 995m by conventional excavation.
The tunnel is part of the Bagbasi water resources scheme, in Hadim district of Konya province, and is being developed by the Directorate of the State Water Works. Groundbreaking on the scheme was mid-2007.
The Mavi machine
