HNTB Corp. has been selected as independent design verifier on the Istanbul Strait Crossing tunnel project in Turkey, connecting the European and the Asian sides of Istanbul by a road tunnel in a high seismic zone and under extreme water pressure. The project will be delivered by public-private partnership procurement. Anticipated completion date for the tunnel is 2016.
The tunnel is approximately 3.3 miles (5.4 km) in length and includes 2.1 miles (3.8 km) of 44-ft diameter (13.4 m), single-bore, double-deck tunnel boring machine tunnel under the Bosphorus Strait; twin bored complex geometry tunnels using New Austrian Tunneling Method; cross passages; transition structures, cut-and-cover and U-shape approaches; portal structures, toll plazas, ventilation facilities, tunnel control and other support facilities and multiple complex structures, interchanges and facilities on both sides of the strait.
“Key to selection was HNTB’s grasp of the technical issues of the project, the depth of our knowledge and understanding of the client’s main concerns, and our resolve to deliver the project on time,” said Sanja Zlatanic, chief tunnel engineer. “Our approach was focused on delivering services to meet the client schedule and performing independent analyses to identify potential for cost savings.”
HNTB’s scope of work will include performing design review and Category 3 independent check of the design to verify that it is done correctly and in accordance with the project design criteria, owner’s requirements, and international codes and standards. In addition, the team will review and verify the project geotechnical parameters and perform independent analyses for the bored tunnel, NATM tunnels, cross passages, transition boxes and cut-and-cover structures. HNTB also will conduct seismic analyses and perform ventilation and fire life safety modeling. In addition, HNTB will perform value engineering and provide recommendations for constructability and construction planning.