Main Construction Begins on Gezhouba Navigation Capacity Expansion for Three Gorges New Waterway

On October 10, construction officially commenced on the upstream and downstream cofferdams for the Gezhouba navigation capacity expansion, a key component of the Three Gorges new waterway project. Together with the riverbank slopes, the two cofferdams will enclose the work area, creating the preconditions for dry-land construction of the new 10,000-ton ship locks. This milestone marks the full entry of the Gezhouba navigation expansion into its main construction phase.

Groundbreaking Ceremony for Downstream Cofferdam of Gezhouba Navigation Capacity Expansion Project

Located on the left bank of the Gezhouba hub, the navigation capacity expansion project will decommission the existing No. 3 ship lock and build two new 10,000-ton locks on-site, each with an effective chamber dimension of 280 meters by 40 meters by 8 meters. Upon completion, single 10,000-ton vessels will be able to navigate smoothly through the Gezhouba hub.

The cofferdams are the first critical engineering barrier for the Gezhouba navigation capacity expansion, serving as in-river water-retaining structures. Simply put, a cofferdam is an in-river barrier that cordons off the lock construction site from surrounding waters. Once the foundation pit is drained, construction crews can carry out demolition of the old lock and excavation and concrete placement for the new locks just as they would on dry land.

Contracted by CCCC Second Harbor Engineering Company, the downstream cofferdam has a total length of 960.85 meters and consists of four sections: a concrete cofferdam, a steel pipe pile cofferdam, an earth-rock cofferdam, and a rock-berm cofferdam.

"The cofferdam construction zone lies within the core navigable waters of the Gezhouba hub. We must capitalize on the low-water window to achieve scheduled water shut-off, while coordinating navigation guarantee and other related work," said Wang Xiao, Deputy Director of the Gezhouba Expansion Project Management Department at China Three Gorges Corporation's Three Gorges New Channel Company.

During construction, the Gezhouba No. 2 ship lock will remain operational, and navigation controls will be implemented on relevant water sections in accordance with notices issued by maritime authorities.