ABSTRACT
3 Deck Great Istanbul Tunnel Project aims to connect Europe and Asia under the Bosporus via Metro and Highway systems in a single tunnel. The constructability plays a vital role. In the Bosporus crossing section of the project there are many engineering challenges such as; extreme hydrostatic pressure, variable soil conditions, extensive diameter of the tunnel, limitation of the tunnel construction time, design of transition structures and TBM launching and receiving structures including logistic area requirements under dense urban patterns, setting out a common alignment for two different means of transport systems having discrete origins and destinations and a limited time frame for the overall design. This paper will present its readers the encountered problems and developed solutions during the design process.
