April 18, in Ningbo, Zhejiang
It was built by the 14th Bureau of China Railway
The construction site of the Jintang submarine tunnel of the Yongzhou Railway
The cutterhead of the shield machine with a diameter of 14.57 meters and a weight of 460 tons
Successfully hoisted down the well
It marks the completion of the assembly of the "Yongzhou" shield machine
The world's longest undersea high-speed rail tunnel
The countdown to the start of the shield has begun
With a total length of 135 meters and a weight of 4,350 tons, the "Yongzhou" shield machine will start from the Ningbo working shaft and excavate 4,940 meters, passing through many complex formations such as soft and hard at the bottom and geological structure zones for a long distance, and finally achieve precise docking and dismantling on the seabed.
Cutterhead hoisting down the well is the most important part of the whole assembly stage, but also the most difficult process, need to two crawler cranes with a lifting capacity of 800 tons, 400 tons of collaborative operation and precise cooperation, through a series of operations such as lifting, turning, rotating, hoisting and going down, the cutterhead is successfully installed on the main drive.
According to reports, the Ningbo end shield launch shaft is up to 58 meters deep, is the deepest large-diameter shield launch shaft in China, the cutterhead is facing difficulties such as narrow site and huge hanging objects. In order to ensure the smooth launch of the cutterhead of the shield machine, the project team customized a series of equipment, analyzed the surrounding environment and on-site layout of the cutterhead hoisting and other factors after 7 simulations, reasonably set up the crawler crane position, and the surface operators and underground operators worked closely together to realize the accurate docking of the cutterhead and the shield.
After the positioning and installation of the cutterhead is completed, the follow-up work such as pipeline connection, no-load test of each system and joint debugging and joint test of the whole machine will begin.
Yongzhou railway project is about 77 kilometers long, with a design speed of 250 kilometers per hour, which is a major project of the national "medium and long-term railway network planning", one of the top ten landmark projects in the construction of large corridors in Zhejiang Province, and the number one project of the Zhoushan comprehensive transportation battle. (China Railway 14th Bureau)