Chinese engineers pioneer innovative subsea tunnel construction in Abu Dhabi

by Xinhua writers Wen Xinnian, Zhao Danliang

ABU DHABI, Dec. 15 (Xinhua) -- Chinese engineers are building an innovative subsea tunnel here using a pioneering "cut-and-cover with cofferdam" method, drawing broad recognition for its technical advancement and efficient execution.

The Abu Dhabi 1B tunnel, connecting Saadiyat Island and Umm Yifenah Island, is being constructed by a consortium led by China Railway International Group starting from October 2024. Instead of conventional shield tunneling or immersed-tube methods, the team created a dry work area by enclosing a sea section with a single-row steel pipe pile cofferdam and pumping out the water.

The excavation has finished, and the cofferdam, which has been successfully closed, remains stable. The project now enters the main structural phase.

Highlighting the scale of innovation, project manager Liu Kun said the single-row steel pipe pile cofferdam "is the first of its kind in the world," noting that as the tunnel's lowest point lies 27 meters below sea level, it must withstand enormous seawater pressure with critical stability and watertightness.

"This has never been attempted on such a scale, either in the region or globally," Liu said.

Dorukhan Kellecioglu, head of the design team of the Swiss-based global engineering and consulting services provider PINI Group, said the achievement has exceeded his expectations.

"We could hardly imagine that a single-row steel pipe pile cofferdam could work in practice. This is a remarkable engineering innovation and a strong showcase of China's infrastructure capabilities," he said.

The project also demonstrates effective global collaboration and management. Hu Peng, project head from China Railway International Group, called the project a model of effective overseas consortium management.

"By bringing together strong partners and exercising full-process control over technology, risk, and resources, the project has progressed steadily and efficiently," he said.

Upon the completion expected by the end of 2026, the tunnel will enhance local connectivity. Wu Lebin is the deputy general manager of the international business department of China Railway Tunnel Group. He said the tunnel "will help optimize the local transport network and support regional economic development."

"This is another concrete example of how China-UAE cooperation under the Belt and Road Initiative is creating real value on the ground," he added. ■