TBM EXCAVATIONS COMPLETED AT THE SARIYER-KILYOS TUNNEL
Another major milestone has been reached in the Sarıyer–Kilyos Tunnel Project, which will strengthen Istanbul's north–south transportation axis. Following the completion of excavation works carried out using a Tunnel Boring Machine (TBM) and the extraction of the TBM from the tunnel, a ceremony was held in Istanbul on Saturday, 7 February, attended by Minister of Transport and Infrastructure Abdulkadir Uraloğlu, Director General of Highways Ahmet Gülşen, company representatives, and officials from the General Directorate of Highways.
TBM used for the first time in highway tunnels
Speaking at the ceremony Minister of Transport and Infrastructure Abdulkadir Uraloğlu emphasized that the project marked the first use of a TBM in highway tunnels. Highlighting that constructing roads and tunnels in mountainous and rugged areas requires extra care and cost at every stage from ground surveys and excavation methods to logistics and safety measures. He stated that the TBM method offers a safe and fast solution, particularly for the construction of long tunnels in residential areas. He noted that the 13.65-meter-diameter TBM used in this project is the third largest TBM ever used in Türkiye, after the Eurasia Tunnel and the T-1 Tunnel between Eşme and Salihli on the Ankara–İzmir High-Speed Railway Line.
The TBM technology and NATM method were applied simultaneously
Minister Uraloğlu stated that the project, which began construction in May 2022, is being built as a twin-tube tunnel approximately 7 kilometers long with two lanes in each direction, and that the total length, including the connecting roads, reaches 8.2 kilometers. As part of the project, he stated that Project includes two interchanges, one viaduct, two cut-and-cover structures and one culvert.
Uraloğlu stated that the 4,800-meter excavation, which began in December 2024 using a TBM, has been successfully completed, and emphasized that, to complete the tunnel as quickly as possible, the NATM method (New Austrian Tunneling Method), a drill-and-blast technique, and TBM technology were applied simultaneously.
Uraloğlu stated that excavation works on the remaining 2,882-meter section of the project are also being carried out using the NATM method. He added that in the sections opened with NATM, 5,135 meters of lining concrete work have been completed to date, with 180 machines/equipment and 879 personnel continuing the works on site. He further noted that, aiming to complete the tunnel this year, construction continues around the clock, seven days a week, without interruption.
Rapid integration will be achieved between the tunnel and its surrounding areas.
Uraloğlu stated that upon completion of the project, nearby settlements will be directly connected to the Northern Marmara Motorway, reducing travel time from 35 minutes to 5 minutes and generating annual savings of 4 billion lira, including 3.3 billion from time and 700 million from fuel. He also emphasized that the tunnel will serve a critical function in emergency evacuation and relief routes in the event of a possible disaster.
Rapid Progress and Construction Safety with TBM
Speaking at the ceremony Director General of Highways Ahmet Gülşen remarked on the project's technical aspects and strategic significance in transportation. He stated that the Sarıyer-Kilyos Tunnel establishes a high-standard transportation corridor connecting Istanbul's central districts to the Nothern Marmara Motorway.
Gülşen stated that in the construction of the twin-tube tunnel, which is 13,715 meters long in total, the NATM method and TBM technology were used together, thereby enhancing both the excavation progress and costruction safety. He noted that the completion of the excavation works carried out with the TBM represents an important milestone.
Sustainable and Safe Solutions Continue to Be Delivered
Gülşen stated that with the implementation of the project, the connection of Sarıyer, Kilyos, Zekeriyaköy, Uskumruköy, and surrounding settlements to the city center will be significantly improved, while access to the Northern Marmara Motorway and Istanbul Airport will become faster and uninterrupted.
Emphasizing that the General Directorate of Highways continues to provide long-term, safe, and sustainable solutions to meet the growing transportation needs of major cities, Gülşen noted that the Sarıyer–Kilyos Tunnel is an important example of this approach in İstanbul.
