Constructors successfully completed boring a tunnel across the Yellow River in east China's Shandong Province on Sunday.
Located in Jinan, the provincial capital of Shandong, the 5.75 km tunnel is set to open to traffic in the latter half of next year, which will reduce the Yellow River crossing time to just five minutes.
Constructed by using a "Shanhe" shield machine with a 17.5-meter excavation diameter, this double-deck, two-way, six-lane tunnel stands as the world's largest-diameter underwater tunnel completed by a shield tunneling machine.
The complex geological conditions in the region, coupled with stringent subsidence control requirements during the tunneling process, presented significant challenges for the construction team.
"We overcame technical challenges such as controlling embankment subsidence when crossing the perched river and implemented green and efficient treatment of large amounts of mud, achieving rapid and safe excavation at a speed of up to 18 meters per day," said Zhou Xiang, on-site manager of the tunnel project.
Tunneling through the perched river with such a large tunneling machine also presented extremely high demands for precise tunneling control and machine reliability.
"We equipped the machine with a pressurized cutter head featuring a larger opening and installed additional flushing pipelines at the center of the cutter head to effectively prevent clogging issues. An intelligent system was also integrated to provide the machine with a 'smart brain', enabling it to achieve full-process perception, early warning, and intelligent decision-making during tunneling. This ensures its safe and efficient passage under the Yellow River," said Wang Xianguo, chief shielding machine operator of the project.
The Yellow River, China's second-largest river after the Yangtze, is known as the country's "Mother River" and the cradle of Chinese civilization.
Boring of tunnel across Yellow River completed in China's Shandong
