IRF GRAA Winner Profile: Eurasia Tunnel
New Road Connection Linking Europe to Asia Scoops IRF Global Road Achievement Award
The Eurasia Tunnel was built to connect the Asian and European sides of Istanbul for the first time via a 3.4-km twin-deck road tunnel going underneath the seabed. The 14.6 kilometer Eurasia Tunnel route was identified based on extensive feasibility studies conducted in 2005, for the Ministry of Transport, Maritime Affairs and Communications of Turkey. Its main aim was to relieve Istanbul’s transcontinental traffic pressure, reduce travel time and reduce harmful emissions from road traffic.
The project was successfully tendered as a Build-Operate-Transfer project in 2011 to ATAŞ, a special purpose company formed by Yapı Merkezi and SK E&C. The project was completed in 47 months and 3 days, almost 8 months ahead of schedule for a total investment cost of USD 1.3 billion.
The tunnel is designed for passenger vehicles and small vans with a limited vertical clearance of 2.8 m. The Tunnel Boring Machine (pictured) used for this project ranks “first” in the world with its 33.3 kW/m2 power per area of cutter head and operating pressure of 12 bars for an excavation diameter of 13.7 meters.
Other key challenges overcome during the project it the tunnel location located in a seismically active region, about 17 km to the North Anatolian Fault Zone. In order to decrease the stresses and strains forming in the tunnel lining during a seismic event below the permissible levels, two flexible seismic joints were designed specifically for the geological and geotechnical conditions, tested in laboratory; and implemented as an industry first in TBM tunneling under such high pressure.
The project is considered as a pioneer project not only on account of these technical challenges, but also in respect of its environmental and social policy with the implementation of a comprehensive Environmental and Social Impact Assessment process.
The tunnel opened for operations in December 2016 and will be transferred to the public after 25 years of operation.