The Shenzhen-Zhongshan Link's subsea immersed tube tunnel will be completed today (November 28), which also means that this highly anticipated core transportation hub project in the Guangdong-Hong Kong-Macao Greater Bay Area will achieve main line completion. The 24-kilometer Shenzhen-Zhongshan Link is located in the core area of the Guangdong-Hong Kong-Macao Greater Bay Area, spanning the east and west banks of the Pearl River Estuary, connecting Shenzhen, Guangzhou, and Zhongshan. It is a cross-sea cluster project integrating "bridges, islands, tunnels, and underwater interchanges" and is currently the most difficult cross-sea cluster project in the world in terms of comprehensive construction. Why adopt this cluster form? What are the difficulties of the project?
CCTV reporter Li Weidai: I am now on the bridge at the Hengmen Interchange in the Cuiheng New District of Zhongshan. This is part of the Shenzhen-Zhongshan Link bridge project and also the starting point of the Shenzhen-Zhongshan Link from Zhongshan to Shenzhen. Vehicles coming from Shenzhen to Zhongshan connect here via the Zhongkai Expressway and the Guang'ao Expressway and other expressways.

In less than 2 minutes of driving from the Hengmen Interchange, the car drove onto the Zhongshan Bridge of the Shenzhen-Zhongshan Link.

CCTV reporter Li Weidai: The vehicle is driving on the Zhongshan Bridge. Looking out from the window, the sea and sky merge into one color on both sides, very expansive. The bridge section of the Shenzhen-Zhongshan Link winds like a giant dragon over the Lingdingyang. This S-shaped design is based on considerations of multiple factors such as hydrology and geology, flood control, and aviation height restrictions, and also makes driving more comfortable and safe.

Driving about 2 kilometers east from the Zhongshan Bridge, that is, toward Shenzhen, a Wanqingsha Interchange has also been specially designed on the non-navigable span bridge. Vehicles can achieve convenient interconnection among Zhongshan, Guangzhou Nansha, and Shenzhen here.

The 24-kilometer Shenzhen-Zhongshan Link has a 22.4-kilometer sea-crossing section, crossing three main shipping channels of the Lingdingyang, and adopts the scheme of a bridge in the west and a tunnel in the east.

The 17,129-meter bridge section, from west to east, consists of the Zhongshan Bridge, the West Non-navigable Span Bridge, the Lingdingyang Bridge, and the East Non-navigable Span Bridge. Among them, the Lingdingyang Bridge has a deck 91 meters above the sea surface and a main span of 1,666 meters. It is the world's largest-span all-offshore sea steel box girder suspension bridge, with a navigational clearance of 76.5 meters. It is currently the sea bridge with the highest navigational clearance in the world and can in the future meet the navigation needs of 300,000-ton bulk carriers and 30,000-TEU container ships.

Song Shenyou, Director and Chief Engineer of the Shenzhen-Zhongshan Link Management Center of Guangdong Transportation Group: Our entire project crosses the three main shipping channels of the Lingdingyang sea area, including the Fanshi Waterway on the Shenzhen side, which is planned at a shipping grade of 100,000 tons. Upstream on the Shenzhen side is Bao'an International Airport, so the entire project must not only meet the needs of future shipping development but also meet aviation height restrictions. The risks of the entire project, especially operational risks, are more controllable, the project scale is moderate, and the bridge-tunnel combination scheme is better than the all-tunnel scheme. In order to achieve rapid traffic conversion between the bridge and the tunnel, the West Artificial Island was set up on the central shoal.

CCTV reporter Li Weidai: The West Artificial Island of the Shenzhen-Zhongshan Link is also the key structure for the bridge-tunnel conversion of the Shenzhen-Zhongshan Link. From here, the Shenzhen-Zhongshan Link begins the 6,845-meter subsea tunnel section. In the future, cars will drive from here below sea level, and at the deepest point they will travel in the immersed tube tunnel 39 meters below sea level.

The immersed tube tunnel of the Shenzhen-Zhongshan Link is the world's first two-way eight-lane subsea tunnel and also the world's largest steel shell-concrete immersed tube tunnel. Passing through the tunnel in about 6 minutes brings you to the East Artificial Island.

Song Shenyou, Director and Chief Engineer of the Shenzhen-Zhongshan Link Management Center of Guangdong Transportation Group: In the future, people on the west bank of the Pearl River will achieve rapid traffic conversion with Shenzhen Airport and Qianhai through an underwater hub interchange set up on the east bank in the form of an expressway. Therefore, the Shenzhen-Zhongshan Link ultimately adopts a cross-sea cluster project integrating bridges, islands, tunnels, and underwater hub interchanges.

The Shenzhen-Zhongshan Link is located in the super typhoon area of the Lingdingyang sea area, crosses 11 fault structural belts, and takes into account multiple functional needs such as aviation, shipping, flood passage, and tidal influx along the entire line. It is built to the standard of a two-way eight-lane expressway, with a design speed of 100 kilometers per hour and a design service life of 100 years. In December 2016, the advance project of the West Artificial Island started construction.

Chen Weile, Construction Commander of the Shenzhen-Zhongshan Link: The overall scale of the Shenzhen-Zhongshan Link is very grand and the technology is very complex. The preliminary work began in 2010 and lasted for 8 years. Full construction started in 2018. It has produced 10 world-first equipment items, including the "intelligent pouring equipment and system for steel shell-concrete immersed tubes," and achieved 10 internationally leading technologies, including "wind resistance and disaster prevention technology for super-large-span suspension bridges in super typhoon areas." This will form a complete set of technologies and a Chinese solution for cross-sea cluster project construction with Chinese standards, and will also provide technical reserves and management experience for building other cross-sea passages or strait projects, further promoting the high-quality development of China's industrial chains in intelligent construction, equipment manufacturing, and intelligent green development in the infrastructure field.

At present, the entire Shenzhen-Zhongshan Link is undergoing the installation of mechanical and electrical, fire protection, traffic safety, and other facilities and equipment, and is planned to be ready for traffic in June next year. After opening to traffic, the driving time between Shenzhen and Zhongshan will be shortened from the current about two hours to less than half an hour, and the daily traffic volume is expected to reach 100,000 vehicle trips. The Shenzhen-Zhongshan Link is of great significance for building and improving the comprehensive three-dimensional transportation network of the Guangdong-Hong Kong-Macao Greater Bay Area. It will further shorten the time-space distance between the east and west banks of the Pearl River Estuary and improve the Greater Bay Area's level of "hard connectivity" and "soft connectivity."