Project Eurasia Tunnel: BAUER Spezialtiefbau GmbH installs diaphragm wall on the Bosphorus

The 5.4-kilometer-long twin-deck Eurasia tunnel, a large part of which will cross the Bosphorus under the seabed, will connect the Asian part of Istanbul with its European part. Construction work for the new motorway tunnel started at the beginning of 2013. Lead contractors are Yapı Merkezi İnş. Ve San. A. Ş. from Turkey and their Korean partner, SK Engineering. A tunnel boring machine is already in operation. In 2014, BAUER Spezialtiefbau GmbH installed a total of 18,900 square meters of diaphragm wall with a depth of up to 39 meters and a thickness of up to 1.5 meters on the European side of the construction site, where the tunnel boring machine will finally emerge. A BAUER BC 40 trench cutter was used for the installation.

The local soil conditions range from highly porous soil to highly weathered, unstable rock, which initially made the cutting work difficult. In addition, a 35-meter-thick solid concrete secant pile wall had to be cut through, which had been constructed beforehand for the operation of the tunnel boring machine. Despite these circumstances, Bauer Spezialtiefbau was able to complete its work by December 2014, as planned, without any delay.

The tunnel is scheduled for completion by the end of 2016. It is expected to ease the severe traffic congestion in Istanbul, the most populous city in Turkey.