Main Construction of Gezhouba Navigation Capacity Expansion Project for the New Three Gorges Water Transport Channel Kicks Off

According to Xinhuanet, construction of the upstream and downstream cofferdams for the Gezhouba navigation capacity expansion project of the New Three Gorges Water Transport Channel started on October 10. The two cofferdams, together with bank slopes and other structures, will enclose the construction zone to create preconditions for dry-land construction of the new 10,000-ton ship locks, marking the full launch of main works for the Gezhouba navigation capacity expansion project.

Located on the left bank of the Gezhouba Hydropower Complex, the Gezhouba navigation capacity expansion works constitute one of the two major components of the New Three Gorges Water Transport Channel. The project will demolish the existing No.3 ship lock and build two new 10,000-ton ship locks on the original site. Each lock chamber measures 280 meters long, 40 meters wide and 8 meters high.

The cofferdam serves as the first critical construction procedure of the Gezhouba navigation capacity expansion project. As a water-retaining enclosure structure built in the river, it separates the ship lock construction area. After draining water from the foundation pit, crews can carry out demolition of the old ship lock, excavation and concreting for new locks under dry-land conditions.

The upstream cofferdam is a Class I temporary hydraulic structure with flood control standards aligned with the main dam of Gezhouba. It stretches 835.94 meters with a maximum height of 28 meters. The total construction period lasts 24 months, involving dredging volume of approximately 518,000 cubic meters and filling volume of around 1,015,200 cubic meters. The downstream cofferdam comprises concrete cofferdam, steel pipe pile cofferdam, earth-rock cofferdam and rock ridge cofferdam, with a total length of 960.85 meters.

The cofferdam construction site lies within the core navigation waters of the Gezhouba Hydropower Complex. Construction needs to seize the low-water window period to ensure timely closure of cofferdams while coordinating navigation guarantee and other related tasks. The project team will strengthen whole-process safety and quality control, push forward cofferdam construction with high standards and lay a solid foundation for subsequent main construction of ship locks.

According to the Ministry of Transport, the project also includes dredging and expansion of upstream and downstream approach channels with a total construction period of 95 months, including a 12-month preparation phase, designed for passage of 10,000-ton vessels. Upon full completion, the Three Gorges Hub will have four ship locks plus a ship lift with an overall throughput capacity of 336 million tons. The Gezhouba Hub will form a layout of four ship locks with a total throughput capacity of 360 million tons.