Photo: Screenshot from China Media Group

The world's largest-diameter high-speed railway shield tunneling machine independently developed in China, known as Linghang, for the Chongming-Taizhou tunnel under the Yangtze River, reached the 10,000-meter tunneling milestone on Tuesday, with only 1,000 meters remaining to the southern bank of the Yangtze River, according to China Media Group (CMG).

This is the first time in the world that a shield tunneling machine with a diameter of 15 meters has achieved a single continuous tunneling of 10,000 meters. It is also a critical step for the tunnel project toward completing the "final kilometer" and carrying a high-speed rail line crossing the river at 350 kilometers per hour, the CMG reported.

The tunnel will significantly shorten the travel time among cities along the Yangtze River, such as Shanghai, Nanjing, and Hefei, better supporting the high-quality development of the Yangtze River Economic Belt.

The tunneling machine is equipped with the world's most advanced "brain" system, which has achieved breakthroughs in core technologies such as adaptive pressure control within the shield chamber, independent decision-making of cloud-based predictive data, and autonomous cruising of tunneling posture. Compared with manual operation, the parameters for tunneling, slurry circulation, and posture are more stable, according to the Science and Technology Daily.

It has enabled the routine application of fully algorithmic, unmanned intelligent tunneling across the entire system, setting a world record for a monthly advance of 718 meters in a 15-meter-class high-speed railway tunnel, according to the report.

Shield tunneling machines, formally known as tunnel boring machines (TBMs), are hailed as the "king of construction machinery" due to their immense scale and complexity. Once limited to horizontal excavation, today's Chinese-developed TBMs can operate in multiple situations including vertical, inclined, and curved trajectories, earning the nickname "transformers" for their adaptability and precision, according to the People's Daily.

In October 2017, China's first domestically developed 15-meter-class slurry balance TBM known as China Railway 306 rolled off the assembly line, breaking the longstanding foreign monopoly in this field. Since then, China has successively rolled out the 15.8-meter Chunfeng, the 16.07-meter Jinghua, and the 16.6-meter-plus Jianghai. Chinese-manufactured TBMs now account for nearly 70 percent of the global market, the People's Daily reported.

Global Times