On July 16, the construction of Wuhan Metro Line 12 in Wuhan, Hubei province achieved a significant milestone as its Yangtze River tunnel section was successfully bored through, completing the breakthrough for China’s longest loop metro line.
Constructed by China Railway 14th Bureau Group Corporation Limited and jointly invested by China Railway Construction Investment Group Corporation Limited, both subsidiaries of China Railway Construction Corporation Limited, this project spans 59.9 kilometers with 37 stations.
Serving as the country’s longest loop metro line, it provides convenient transfer opportunities with 18 lines within Wuhan’s metro network plan.
The tunnel section between Danshuichi Station and Science Popularization Park Station crosses the Yangtze River and spans 4,011 meters. It is a single-bore, double-track tunnel constructed using the 12.55-meter-diameter slurry shield machine. As a critical control section of the entire line, this tunnel presented significant technical challenges.
The shield machine faced a 2,160-meter-wide river crossing with a maximum burial depth of 45.5 meters, cutting through geologically complex strata. These included severely weathered mudstone — prone to causing clay clogging and slurry discharge blockages — and layers that led to heavy wear and frequent cutter replacements.
To overcome these challenges, the project team utilized a shield tunnel big data monitoring platform and a BIM data platform to continuously optimize construction plans. They employed automated monitoring technology, optimized cutter configurations, used wear-resistant materials to extend tool life, and installed rotational monitoring devices on cutterheads and tools. This meticulous approach ensure the tunnel’s successful passage beneath critical zones such as railway utility corridors, the Yangtze River levee, the main waterway, and operational high-speed rail lines.
The project team’s technological breakthroughs and innovations yielded significant results, including 21 authorized national patents and more than ten awards and recognitions, such as the National Invention and Entrepreneurship Innovation Award and top honors in engineering micro-innovation contests. These achievements provide strong technical support for similar tunnel projects.
Once operational, the section connecting Qingshan and Jiang’an districts will reduce travel time between the two areas to just five minutes. The project is expected to alleviate passenger flow pressure in central Wuhan, accelerate development in key urban zones, and further enhance the city’s comprehensive transportation network.
(Executive editor: Yuan Ting)
