The DN1000 Self-Anchored Pipe Immersed Tunnel Project Sets A New Industry Record

Recently, the immersed tunnel construction for the water supply pipeline relocation project on the Changqiao section of the Suzhou section of the Beijing-Hangzhou Grand Canal was successfully completed. The project utilized DN1000 self-anchored ductile iron pipes, implementing a 150-meter-long immersed tunnel operation across the river, setting new domestic industry records for both the length and diameter of immersed tunnels constructed with ductile iron pipes of the same diameter.

As a key supporting project for waterway improvement, the project spans the main channel of the Beijing-Hangzhou Grand Canal, presenting extremely high construction challenges. The work area was 9 meters deep with complex geology, and the entire immersion process had to be completed within a 6-hour navigation closure window, leaving very little room for error. The construction team selected a solution after comparing multiple construction methods, leveraging the advantages of customized self-anchored pipes to successfully overcome challenges such as shore-side transportation and water-based hoisting.

Its flexible socket joint and self-anchored anti-pull-out design effectively resisted water flow impact and construction disturbance, ensuring immersion accuracy and structural stability. This breakthrough fills a gap in the application of large-diameter ductile iron pipes in the field of immersed tunnel construction in main river channels, providing a replicable model for similar projects.