On December 7, the No. 1 shaft of the Songyang Pumped Storage Power Station in Zhejiang Province was completed, reaching a depth of 637 meters, making it the deepest shaft of its kind in China. This achievement marks a major breakthrough in China’s advanced construction of ultra-deep shafts for pumped storage power stations.
The No. 1 shaft of the Songyang Pumped Storage Power Station in Zhejiang Province was completed, reaching a depth of 637 meters, making it the deepest shaft of its kind in China. [Photo/sasac.gov.cn]
The shaft was excavated using China’s first full-section reaming ultra-deep shaft boring machine, adopting an innovative one-time forming method for slag expansion support. The guiding shaft achieved a maximum deviation rate of only 0.216‰, well below the industry standard of 0.5‰, and the maximum diameter deviation after expansion was within 6 millimeters—both setting new industry benchmarks.
The project also set four new industry records: a maximum daily advance of 20.18 meters, a maximum monthly advance of 236.96 meters, a monthly average of 204.98 meters, and the completion of excavation and support for the ultra-deep shaft in just 2.5 months.
The Songyang Pumped Storage Power Station, located in Songyang County of Lishui City and built by China Three Gorges Corporation, is a pure pumped-storage plant designed for daily peak shaving. It features four 350-MW reversible pump-turbine generator units and consists of upper and lower reservoirs, a water conveyance system, an underground powerhouse, and a surface switchyard. Its water conveyance system features a single-stage vertical shaft arrangement.
To address these challenges, China Three Gorges Construction Engineering Corporation led the development of China’s first complete intelligent equipment system for 700-meter-class ultra-deep shafts. This includes the country’s first full-section reaming hard-rock ultra-deep shaft boring machine and the world’s tallest 700-meter-class intelligent hoisting system.
The Songyang project will play a key role in peak shaving, valley filling, energy storage, frequency and phase regulation, and emergency backup for the power grid in Zhejiang Province. Once operational, it will work with other pumped storage facilities to support flexible dispatching in the East China grid, promote the consumption of renewable energy, optimize grid structure, and enhance power system safety and stability. It will also contribute to China’s “dual-carbon” goals and the development of a new energy-dominated power system.
(Executive editor: Yuan Ting)
