The world's longest shield tunnel crossing a river has passed the lowest point of the riverbed
Under water, where pressure compresses everything around and the soil forgives no mistakes, humans are carving a path that connects shores and destinies. Technology and perseverance make it possible to overcome where nature itself seems to stand against you. This tunnel is not just a transport artery but a symbol that even beneath the longest river a bridge between people can be built.
On Monday, the left tube of the Haitai-Yangtze two-tube tunnel, the world's longest shield tunnel crossing a river, successfully passed the lowest point of the riverbed, marking the completion of the passage through the lowest point of both tubes and laying a solid foundation for its full completion. The tunnel, located in eastern China's Jiangsu Province, is a key project for creating a major road link across China's longest river, connecting Haimen in Nantong City with Taicang in Suzhou City in the same province.
As shown in the video, at a depth of 75 metres below the surface of the Yangtze River estuary, China's domestically developed shield boring machine "Cangyuan" completed drilling 5,334 metres and safely passed through the lowest point of the riverbed. This section was the most critical part of the project, where construction risks were most concentrated and difficulties the highest. The tunnel structure had to withstand extremely high water pressure of 0.75 MPa, equivalent to the combined weight of about 51 vehicles, each weighing 1.5 tonnes, per square metre.
"Facing problems such as high water pressure in the riverbed, equipment abrasion by sand with high quartz content and significant geological changes, the technical team constantly adjusted key parameters. Relying on intelligent equipment and technologies, we tracked data, carried out intelligent analysis and optimised parameters in real time, successfully overcoming complex technical challenges," said Zhao Xiaopeng, project engineer.
The tunnel has a total length of about 39.07 kilometres, including an underwater section of 11.185 kilometres, with the shield section of the left tube being 9,327 metres long. It is designed as a six-lane, two-way expressway with a speed limit of 100 km/h. Construction is scheduled for completion in 2028. Once finished, it will become a vital transport link in the Yangtze River Delta in eastern China.
As reported by CCTV+, the successful passage of both tubes through the lowest point of the riverbed of the Haitai-Yangtze tunnel marked an important milestone in this large-scale infrastructure project, which will strengthen transport links in the Yangtze River Delta and serve as an example of Chinese engineering excellence.
