Workers in China have set a new world record by completing the construction of the world’s largest-diameter underwater shield tunnel, marking a major milestone in infrastructure development. A two-mile section of the tunnel, with an impressive diameter of 55.8 feet (17 meters), has been finished, featuring 500 pipe rings of underwater shielding. The work is part of an ambitious project to build a 3.6-mile tunnel beneath the Yellow River in Jinan, the capital of Shandong Province, East China.
Currently under construction 98 feet below the surface, the tunnel will be a critical north-south route connecting key areas in Jinan. It will feature a two-way road with three lanes in each direction, designed to accommodate vehicles at a speed of 37.2 miles per hour (60 km/h). The project aims to enhance the region’s connectivity and is set to be completed by late 2025.
China Railway 14th Bureau Group Co., Ltd. is leading the construction of the Jinan Huanggang Road Tunnel, which is set to become a vital piece of infrastructure linking the urban area on the south side of the Yellow River to a newly established state-level strategic pilot zone for free trade, innovation, and reform on the north side of the river.
Record-Breaking Speed and Innovation
The construction process has been nothing short of remarkable. The tunnel’s underwater shielding was completed in just 110 days, thanks to the advanced technology of the “Shanhe,” a state-of-the-art shield boring machine. This mega-boring machine, manufactured by Herrenknecht, made unprecedented progress, advancing between 52.5 and 59 feet per day and covering up to 1,396.6 feet per month. This achievement set a new world record for 17-meter-class shield construction.
The “Shanhe” features a massive cutterhead with a diameter of 57.5 feet—roughly the height of a five-story building—and boasts 7,510 horsepower, providing more than 26 million lb-ft of electric motor and hydraulic power. The machine is equipped with cutting-edge technologies, including a flushing system to prevent clogging, a telescopic camera system for safer maintenance, and a specialized automatic air cushion system that helps balance pressure and prevent collapse or flooding during tunneling operations.
Notably, the “Shanhe” can withstand up to 7.5 times the normal atmospheric pressure (7.5 bar), and its excavation chamber can endure up to 15 bar of pressure, further highlighting the machine’s extraordinary capabilities in challenging underwater environments.
Overcoming Challenges in Construction
While the project has seen significant technological breakthroughs, it hasn’t been without its challenges. One of the major obstacles encountered was the treatment of waste slurry, a byproduct of the tunneling process. The team developed a pioneering solution to address this issue while ensuring environmentally friendly tunneling. This innovative process included the installation of jaw crushers, a dual-line pipeline hydraulic quarrying device, and a waste slurry concentration and filter press system, ensuring minimal environmental impact.
A New Landmark in Underwater Tunneling
At 55.8 feet in diameter, the Yellow River tunnel stands as the largest of its kind in the world, though it is not the longest. For comparison, Japan’s Seikan Tunnel stretches 33.46 miles, and the Channel Tunnel connecting the UK and France is 31.4 miles long. Nonetheless, the Jinan Huanggang Road Tunnel’s significance lies in its strategic location, connecting two vital regions of China and improving infrastructure in one of the country’s most populous areas.
As work continues on this colossal project, the completion of the Jinan Huanggang Road Tunnel promises to further enhance China’s economic and logistical connectivity, solidifying its place as one of the most ambitious infrastructure projects in the world.
By Impact Lab
