Crossing under the Yangtze River in a high-speed train at up to 350 kilometers per hour - this will soon become reality for the first time in Chongqing. On June 16, 2023, the Herrenknecht Mixshield "Yangtze River" started its tunnel drive. With a diameter of 12.66 meters, it crosses under the Yangtze River near Chongqing, Sichuan Province, over a length of 1,282 meters. The total drive length of the TBM is 3,845 meters.
The single-track rail tunnel project will be part of the 11.9-kilometer Chongqing-Qianjiang railway line. It will extend the total length of the high-speed railway to 269.6 kilometers, from Chongqing to Xiangshan.
Passing sensitive buildings and other railroad lines, the tunnel route takes the Mixshield through complex, karstic geology, fracture zones and coal seam gas zones. With a water depth of around 42 meters and a minimum overburden of 10 meters, a water pressure of up to 9 bar must also be expected during tunnel construction.
The high-performance machine from Herrenknecht is equipped with a gas-liquid pressure equalization control and gas detectors for this application. Efficient flushing and high-quality cutter tools support safe tunnelling. In close cooperation with the customer, it was also possible to ensure the start of tunnelling in a very confined space.
