World’s largest tunnel boring machine in China unveiled

China has unveiled its 5,000-ton heavy-duty tunnel boring machine, known as "Jianghai," which has the largest diameter of its kind.

The production of this massive tunnel boring machine, with a diameter of 16.64 meters, has been completed.

This new machine will be used to construct a tunnel beneath the Yangtze River in Jiangsu Province, China, connecting two regions.

"Jianghai" means "river and ocean" in Chinese. The machine weighs nearly 5,000 tons and is 145 meters long, making it the largest tunnel boring machine in the world.

The Jianghai was manufactured by CRCHI (China Railway Construction Heavy Industry Corporation).

A few months ago, China also announced that it had developed the world’s first BBM (boring and blasting machine), which offers 30% greater tunneling efficiency.

Advanced tunnel boring machine

This new tunnel boring machine is designed to build a tunnel across the Yangtze River in Jiangsu Province, connecting the cities of Nantong and Suzhou.

The tunnel will form part of a 39-kilometer highway expected to be completed by 2028.

The tunnel, spanning 11.2 kilometers, will be bored at a depth of 75 meters below the Yangtze River.

According to You Shaoqiang, the chief engineer of the project, this tunnel faces unique challenges due to underground water sources, soft soil, and mud, which make conventional tunneling methods impossible.

Jianghai will bore through the ground at a speed of 12 to 16 meters per day, with the entire tunnel excavation anticipated to take about two and a half years.

Since the tunnel is located near the Yangtze River’s estuary, tunneling precision must remain within one centimeter to ensure the safety of the dams constructed along this waterway.

Jianghai, with its 16-meter diameter and 5,000-ton weight, is comparable in scale to a six-story building.

Strengthening innovation in infrastructure

Zhao Hui, president of CRCHI, stated that this development marks a significant milestone in the industrialization of large-diameter tunnel boring technology, specifically within the 16-meter class, in China.

In 2022, CRCHI produced a 16.07-meter diameter tunnel boring machine for a renovation project in Beijing.

According to Chinese chief engineer Fan Ruiqiang, the team spent over two years developing Jianghai, which is newer and larger than previous models.

Reports indicate that this advanced machine is now more intelligent, equipped with a database that records past tunneling issues.

This feature enables the machine to offer suggestions to operators if similar challenges arise.

Wang Jun, deputy director of the construction office for this project, noted that this tunnel boring machine represents a crucial step forward for the Jiangsu Highway project and a major transportation initiative for China. He added that this machine is a remarkable achievement for China's manufacturing industry, reflecting both the hard work of engineers and China’s progress in large-scale machinery production.

Jianghai employs completely different drilling and blasting methods and is claimed to be a valuable asset for water conservation, mining, railway, and highway projects.

Designed to operate in fault zones and withstand sudden inflows of mud or water, Jianghai’s ring-shaped cutting head enables tunneling in challenging conditions, while its dual-mode function allows simultaneous drilling and blasting, enhancing both speed and efficiency.

Additionally, Jianghai’s hollow cutting head facilitates routing and progress in complex geological conditions.

BY WPB