February 21

A shield tunneling machine with a fierce tiger shark pattern painted on its cutterhead

the "Tuodao" shield tunneling machine completed factory manufacturing and successfully rolled off the production line

The "Tuodao" shield tunneling machine successfully rolled off the production line

This is a domestic large-diameter slurry balance shield tunneling machine jointly developed by China Railway 14th Bureau Group and CRCC Heavy Industry Group. It will be used in the construction of the Shantou Bay Tunnel on the Shantou Guang'ao Port Area Railway and is about to begin its journey across the sea.

Don't get too excited! Open your eyes wide!

The Shantou Guang'ao Port Area Railway is located in Shantou City, Guangdong Province, starting from Shantou Station of the Guangzhou-Meizhou-Shantou Railway in the north and ending at the Guang'ao Port Area in the south. The 1st bid section of the Guang'ao Port Area Railway has a total length of 17.116 kilometers and includes one tunnel, two bridges, and other construction content. The Shantou Bay Tunnel is a key and difficult control project of the works, with a total length of 9,965 meters, of which the shield-driven section is 2,990 meters long. The tunnel segment has an outer diameter of 12.9 meters and an inner diameter of 11.8 meters.

Layout plan of the Shantou Guang'ao Port Area Railway

The shield-driven section of the Shantou Bay Tunnel passes beneath complex strata including soft soil, uneven soft and hard ground, boulders, full-face hard rock, and fault zones. There are 11 fault fracture zones in the Shantou Bay sea area, and construction through high water pressure and shallow cover is extremely difficult. The tunnel crosses beneath many important structures such as the Shenhai Expressway subgrade, posing high construction risks.

Since the start of tunnel construction, the project department has organized multiple internal expert seminars and shield machine selection analysis meetings, invited well-known domestic experts to review the shield machine design, and, based on China Railway 14th Bureau Group's rich experience in shield construction across rivers and seas over many years, carried out targeted design and optimization for the shield machine manufacturing, laying a solid foundation for safe and efficient tunneling of the sea-crossing tunnel.

The "Tuodao" shield tunneling machine

The "Tuodao" shield tunneling machine has a cutterhead excavation diameter of 13.42 meters, a total length of 126 meters, a total weight of about 3,300 tons, and a total installed power of 9,300 kilowatts. The shield cutterhead has functions including atmospheric cutter replacement, interchangeable roller and gear cutters, roller cutter wear detection, rotation speed detection, and temperature detection. To address the low construction efficiency in hard rock strata, the spacing between cutterhead cutters has been further reduced, and pressurized roller cutters have been added, which helps improve rock-breaking efficiency. The cutterhead is equipped with a total of 185 cutters, of which 89 can be replaced under atmospheric pressure, achieving "full coverage" of the cutterhead excavation trajectory.

Technicians operating the "Tuodao"

The tiger shark "stirs the sea," and heavy equipment joins the ranks. The cutterhead painting of the "Tuodao" shield tunneling machine reflects local cultural characteristics. It is understood that Shantou is also known as Tuodao. "Tuo" is a small, round, spotted fish belonging to the shark family, called "shatuo." Because Shantou urban area is located on one side of the Tuoji River and was surrounded by water on three sides, it was historically a peninsula. In the past, the bay was rich in shatou, hence the name "Tuodao."

The Guang'ao Port Area Railway is a convenient channel for port evacuation at Shantou Port and an important route connecting the hinterland. It also reserves the function of carrying part of the passenger transport along the line. After the project is completed, on the basis of comprehensively improving the collection and distribution capacity of the Guang'ao Port Area, it will strengthen north-south regional connections, enhance links with the Guangdong-Hong Kong-Macao Greater Bay Area and the West Coast Economic Zone, and improve the layout of the regional intercity transportation network.