Recently, the Shantou Bay Undersea Tunnel of the Shantou Railway ushered in the "first shot". The world's first single-hole double-track high-speed rail undersea tunnel with a design speed of 350 kilometers per hour has officially entered the substantive construction stage.

Shantou (head) Shantou (tail) railway starts from Shantou station of Guangzhou-Meishan railway and ends at Shanwei station of Xiamen-Shenzhen railway. the total length of the main line is about 162.750km, including 35 bridges with 113.691km and 13 tunnels with 32.404km, with a bridge-tunnel ratio of 89.77.

The Shantou Bay Subsea Tunnel under construction is a key control project of the Shantou Railway. It is located in Shantou City, Guangdong Province. It is constructed by the 14th Bureau of China Railway. It is a single-hole double-track tunnel with a total length of 9781 meters. It is the first design standard in China and the world. A high-speed rail subsea tunnel with a speed of 350 kilometers per hour and a large-diameter shield across the sea.

This tunnel passes through 17 fault fracture zones in the 8-degree earthquake zone, of which 8 are active faults, which is the largest underwater tunnel at home and abroad; most of this tunnel is located in the high water pressure risk area, and the maximum water pressure can reach 0.97 MPa Under such strong pressure, water can form a water column as high as 97 meters, creating the largest underwater tunnel in China.

Because of its long-term occurrence in the high-pressure seawater environment, the tunnel structure needs to adapt to the strong erosion environment while withstanding the high water pressure permeability.

It can be seen that the construction of this tunnel is extremely risky and difficult. How to ensure the waterproof performance, safe operation, and convenient maintenance of the tunnel is a huge challenge for construction units and construction personnel. Therefore, this tunnel has adopted 6 construction methods in different sections. The construction methods are complex and diverse, and the procedures are changeable to ensure the safe operation of high-speed rail trains when passing through the undersea tunnel.

The substantial construction of the Shantou Bay Undersea Tunnel marks a step closer to the completion of the Shantou Railway Construction Project. At that time, after the opening of operation, starting from Shantou Station, the Shantou Railway will go directly to the Shanwei Station of the high-speed railway and transfer to the Guangzhou-Shantou high-speed railway. The original 3-hour drive will be shortened to 1.5 hours to reach Guangzhou.

The Shanshan Railway will form an important channel for eastern Guangdong to integrate into the Guangdong-Hong Kong-Macao Greater Bay Area in the future. Next, Shantou Station will also be connected with the Shanzhang High-speed Railway, and a new north-south high-capacity passenger transport channel will be built between the Pearl River Delta, Hercynian, and the Yangtze River Delta, filling the gap in the layout of the 350-kilometer-per-hour high-speed railway along the coastal channel.