At 9:36 on December 26, the shield machine for the east line of the Shantou Bay Tunnel was successfully launched. This tunnel is the largest-diameter subsea shield tunnel in China, the first shield tunnel located in an area with seismic intensity of 8, and the first underwater shield tunnel combining urban road and Class I highway functions, marking significant progress in the Shantou Bay Tunnel project. The shield machine launched this time was procured by China Railway Tunnel Group through global bidding and tailor-made for the special hydrogeological conditions of the bay tunnel project. The cutterhead has a diameter of 15.01 meters, equivalent to a five-story building; the total length is 130 meters, total weight 4,600 tons, total power 10,800 kilowatts, and it consists of tens of thousands of components. It adopts cutting-edge technologies in the current international shield manufacturing field and features functions such as atmospheric (hyperbaric) cutter replacement, cutterhead telescopic and swinging, advanced geological prediction, and advanced drilling, making it a 'high, precise, and advanced' tunnel construction machine in China.
The Shantou Bay Tunnel project is located between the existing Bay Bridge and Queshi Bridge, consisting of an undersea tunnel, the Nanbin South Road interchange, and north bank connecting works. The total length of the bay tunnel is 6,680 meters, with a shield-driven section of 3,047.5 meters. It has dual three-lane carriageways in two circular tubes, each tube divided into three levels: the upper level is the smoke exhaust duct, the middle is the traffic lane, and the lower is the personnel evacuation passage. Two shield machines are used for the shield-driven section.
The bay tunnel passes through a seabed area underlain by numerous high-strength boulders and three bedrock protrusion sections totaling 182 meters in length. It is characterized by complex geology, extremely high construction difficulty, and high safety risk levels. Academicians Wang Mengshu, Qian Qihu, Sun Jun, Zhou Fulin, Wang Fuming, and others have visited the site multiple times to provide guidance, calling it a 'world-class mega project'.