China's deepest undersea tunnel under construction in Nansha

At the Nansha section of the Pearl River Estuary tunnel of the Shenzhen-Jiangmen Railway, builders have been driving a shield machine into China's deepest undersea tunnel towards Humen, excavating a total of 1,174 meters as of Oct 7.

The Shenzhen-Jiangmen Railway is an important part of the national high-speed rail coastal channel, as well as a major transportation infrastructure project supporting the Guangdong-Hong Kong-Macao Greater Bay Area. It runs through Shenzhen, Guangzhou, Dongguan, Zhongshan, and Jiangmen. It is equipped with a high-speed train depot at Nansha, Zhongshan, and Jiangmen stations, covering a total length of 116 kilometers.

The 13.69-km tunnel is located at the estuary of the Pearl River between Dongguan and Guangzhou, with a designed speed of 250 km per hour and a planned construction period of 56 months.

Among them, China Railway Tunnel Group is undertaking 9,175 meters in construction. The tunnel design speed will be 250 kilometers. With a maximum underwater depth of 115 meters, it is the deepest undersea tunnel in China, while the maximum water pressure of 1.06 mpa is the most in the world.

The research team is building the tunnel by excavating the underground tunnel and using large shield tunneling machines to dig.

According to the design plan, two large-diameter shield tunneling machines will be driven from Humen in Dongguan and Wanqingsha in Nansha district respectively. The outer diameter of the shield tunneling machine is 12.9 meters, while the digging length has reached 3,590 meters the longest.

After the completion of the Shenzhen-Jiangmen Railway, it will further open up the coastal high-speed rail channel, helping create a half-hour living circle and economic circle in the Guangdong-Hong Kong-Macao Greater Bay Area, as well as promoting the coordinated development of Guangdong and the Pearl River Delta region.

The Nansha section of the Pearl River Estuary tunnel of the Shenzhen-Jiangmen Railway. [Photo/WeChat account: nanshafabu]

The Greater Bay Area shield machine [Photo/WeChat account: nanshafabu]