Beijing — China has set a new engineering benchmark by completing the world’s largest-diameter underwater shield tunnel in just 110 days. The achievement, part of the Jinan Huanggang Road Yellow River Crossing Tunnel project, underscores the nation’s rapid advances in large-scale infrastructure development.

According to project officials, construction was carried out using a tunnel boring machine (TBM) with a diameter of 17.5 meters, making it the largest of its kind globally. The tunnel runs beneath the Yellow River in Jinan, Shandong Province, and is designed to improve urban connectivity and relieve congestion in the rapidly growing city.

Engineering achievement

The use of an ultra-large TBM allowed engineers to complete the shield tunneling phase in less than four months — a record-breaking pace for a project of this scale. Shield tunneling is considered one of the most complex methods of underground construction, particularly when executed beneath a major river.

Part of China’s infrastructure drive

This tunnel is just one of many high-profile projects showcasing China’s ability to execute large, technically demanding works. The country is also advancing projects such as the Shenzhen–Zhongshan Link, a mega-crossing in the Pearl River Delta that combines bridges, artificial islands, and an immersed tunnel, set to open in the coming years.

Together, these projects highlight China’s strategy of using innovative construction technologies to enhance regional integration, reduce travel times, and strengthen economic links between major cities.

A symbol of technological progress

Beyond improving transport efficiency, the Jinan Huanggang tunnel demonstrates China’s growing dominance in TBM manufacturing and large-diameter shield tunneling technology. The successful completion of the project in record time is seen as a milestone in both civil engineering and urban development planning, solidifying China’s reputation as a global leader in mega-infrastructure projects.