Eurasia Tunnel

Eurasia Tunnel is designed as the world’s first two-level road tunnel connecting continents. The Eurasia Tunnel, passing beneath the Bosphorus Strait, is a important transportation project that links the two shores of Istanbul (Europe-Asia) via road. It serves the route between Kazlıçeşme and Göztepe, with a total length of 14.6 km.

Design and Construction Phases of the Project

The design phase of the Eurasia Tunnel was carried out by Parsons Brinckerhoff International Inc., an international firm with extensive experience, and certified by HNTB as the independent reviewer. The project was developed as an integrated system in collaboration with the Istanbul Metropolitan Municipality and other relevant public institutions, ensuring compatibility with existing traffic and infrastructure systems.

Construction of the tunnel began on 30 January 2013 and was completed in 47 months and 3 day like short, surpassing the planned schedule of 55 moon, thereby drawing attention for its project efficiency. The tunnel consists of two levels excavated using a Tunnel Boring Machine (TBM) and additional sections constructed using traditional methods (NATM) for land tunnels.

Tunnel Technology and Advanced Techniques Used in Construction

The TBM used in the project, named “Bayezid,” has a cutter head power of 33.3 kW/m², ranking it first in the world. Additionally, the tunnel was specifically engineered to withstand seismic activity due to its proximity to the North Anatolian Fault Line and is equipped with two seismic joints (hinges), the first such application globally. These joints enable tolerance of up to ±50 mm horizontal displacement and ±75 mm vertical elongation/shortening, thereby minimizing earthquake risks.

Due to challenging geological conditions, over 440 cutting discs and 475 brushes were replaced during excavation, and operations requiring maintenance under hyperbaric pressure were conducted. These operations, particularly at the deepest point where pressure reached 10.8 bar, set a benchmark in terms of world scale.

Benefits Provided by the Project

Traffic and Travel Time

• Travel time along the project route has been reduced to as little as 5 minutes.
• Traffic congestion on the 15 July Martyrs Bridge, Galata Bridge, and Unkapanı Bridge has been significantly alleviated.

Environmental Contributions

• An annual reduction of approximately 82,000 tons in exhaust emissions is targeted.
• An aesthetic design incorporating traditional Turkish architectural motifs has been adopted to preserve Istanbul’s skyline.

Economic Contributions

• During construction, employment was provided to 1,800 people daily, generating an economic activity of 1.5 million Turkish Lira per day.
• An annual public revenue of approximately 180 million Turkish Lira is projected during the operational phase.
• An annual fuel saving of 160 million Turkish Lira (approximately 38 million liters) has been achieved.

Safety and Comfort

• A comfortable and safe journey is ensured through modern lighting and high-capacity ventilation systems.
• Security has been elevated to a high level through advanced technological systems including TEDES, SCADA, Intelligent Transportation System, fire alarm systems, and drainage systems.

Operational Management of the Tunnel

The operation of the Eurasia Tunnel is managed by ATAŞ. High safety standards have been achieved through collaboration with Egis Tunnel Operation Company. Traffic management and operational processes are controlled using advanced technological systems such as SCADA and the Intelligent Transportation System. Twenty-six different emergency possible scenarios have been planned to address all possible situation events.

Project Chronology

• 2005: Feasibility studies were conducted by NIPPON KOEI.
• 2008: The project was tendered.
• 2011: The implementation contract was signed and the groundbreaking ceremony was held.
• 2013: Financial closure was completed, the TBM arrived on site, and excavation began.
• 2014: The deepest point was reached and seismic joints were installed.
• 2015: Tunnel excavation was completed.
• 2016: The Eurasia Tunnel was opened to traffic and the first vehicle passage occurred.

Project Firsts and Global Examples

• World’s first two-level road tunnel
• World’s top-ranked TBM technology in terms of cutter head power
• First global application of seismic joint technology to minimize earthquake risk
• Successful execution of hyperbaric maintenance and repair operations at the highest pressure levels ever achieved