New progress! The world's longest undersea road tunnel begins its "sea journey"!

On January 26, the construction of the Qingdao Jiaozhou Bay Second Undersea Tunnel, the world's largest and longest undersea highway tunnel, ushered in new progress. The "Deep Blue" shield machine of the main line north line shield section, constructed by China Communications Construction Tunnel Engineering Bureau, was successfully started, officially starting its journey through the sea.

The Jiaozhou Bay Second Tunnel is a major construction project in Shandong Province, connecting Qingdao and Huangdao. The main line is 17.48 kilometers long and adopts a two-way six-lane main tunnel plus an intermediate service tunnel. The water pressure of the main line north line shield section constructed by the Tunnel Bureau can reach up to 0.96 MPa. The construction needs to face extreme conditions such as the marine environment, ultra-high water pressure, ultra-large diameter shield, and crossing large-scale fault fracture zones.

In view of the construction difficulties such as complex geological conditions, high water pressure, and long-distance hard rock excavation, the project team and authoritative experts in the industry conducted special research on the cutterhead form, tool type, pressure resistance and wear resistance, and tailored the ultra-large diameter slurry balance shield machine "Deep Blue" to adapt to long-distance hard rock formations. The shield machine has an excavation diameter of 15.63 meters, a machine length of 165 meters, a weight of 5,300 tons, and is equipped with intelligent systems such as telescopic main drive and telescopic excavation chamber monitoring.

The smooth departure of the Deep Blue marks the full launch of the construction of the Jiaozhou Bay Second Tunnel Project. It is reported that the departure site is only 8 meters away from the coast, which is the most difficult and risky of the three shield tunnels. The Deep Blue departed from Qingdao and dug into the sea, dismantling the caverns on the seabed to complete the difficult operations such as receiving and dismantling, which will bring the journey through the sea to a successful conclusion.

After the tunnel is completed, Qingdao will usher in the "dual tunnel era", further accelerate the transportation connection between Qingdao and Huangdao, and refresh the "progress bar" of the integrated transportation around the bay. It is of great significance for optimizing the urban spatial structure, promoting the integrated development of the east and west banks of Jiaozhou Bay, and alleviating urban traffic pressure.

Planning and production

Source: People's Daily Client

Editor: He Tong