The construction of Shenzhong (Shenzhen-Zhongshan) Link has entered the toughest section, the construction of an immersed tube.
The 6.8-km tunnel will connect with artificial islands at both ends and link with bridges and expressways.
It will be the first tunnel with eight lanes that uses concrete with steel shells.
The project is tough because the entrance to the tunnel, which connects to the eastern artificial island, will be expanded from eight to 12 lanes because a section of about 615 meters will be used for vehicles to interchange. Inside the tube, the width is being expanded from 46 meters to 70 meters. The deepest part of the tubes will be laid about 40 meters beneath the surface of the water. It is also a big challenge to lay the tubes during the flood or typhoon season.
The eastern artificial island is located near the Shenzhen side, close to Fuyong Port and the Shenzhen airport. The artificial island will serve as a junction where the underwater tunnel links with the ground-level roads and bridges to the Shenzhen airport and other city highways.
The entrances at the western artificial island will be built on an unstable surface, which poses a challenge to foundation trench construction.
Before the end of the year, the fencing project for the western artificial island will be completed and a diamond-shaped land, 930 meters in width and 1,136 in length, will be formed in 2020 to make way for the construction of interchange tunnels for vehicles between the elevated bridges and the underground tunnels, which is expected to be completed in 2023 and put into use in 2024.
The 24-km Shenzhen-Zhongshan Link, a key project for Guangdong, includes two artificial islands, two suspension bridges and the world’s widest immersed tunnel with eight traffic lanes in two directions, which boasts a capacity of 90,000 cars per day.
It starts at Shenzhen’s Airport Overpass, an interchange overpass on the Guangzhou-Shenzhen Riverside Expressway, touches land on Ma’an Island in Zhongshan and terminates at Hengmen Overpass, an interchange overpass on the Zhongshan-Kaiping Expressway and Zhongshan Eastern Outer Ring Expressway.
The 46-billion-yuan (US$6.70 billion) project is located about 38 kilometers north of the Hong Kong-Zhuhai-Macao Bridge and 30 kilometers south of Humen Bridge.
It will connect Shenzhen with the cities of Zhongshan and Jiangmen, cutting more than 100 kilometers off the current journey from Shenzhen to the western part of the Pearl River Delta. After the link is put into use in 2024, the trip to Zhongshan from Shenzhen will be cut to 30 minutes.
Currently, Shenzhen drivers need to pass over the often congested Humen Bridge to get to Zhongshan, and the total trip takes between two and three hours.