As of November 19, the A6 section of the Guangdong Water Resources Allocation Project around the Beibu Gulf, undertaken by China Railway Tunnel Group, achieved significant progress. The largest diameter TBM (Tunnel Boring Machine) in the project, named Yuehai Huanbei No. 5, successfully advanced over 1,000 meters.

This project is a major water resource and livelihood initiative planned by the Guangdong provincial government to support the future development of four cities in western Guangdong. With a total water transmission length of 490.33 kilometers, the project is designed for a water flow rate of 110 cubic meters per second.

The A6 section, constructed by China Railway Tunnel Group, forms part of the Yunkaishan tunnel on the West High Mainline, spanning 24.82 kilometers from the Xijiang intake to the Gaozhou Reservoir. Construction involves two open TBMs and the drill-and-blast method. The Dachen branch tunnel, where this milestone was achieved, extends 10.4 kilometers with a buried depth ranging from 200 to 890 meters. The TBM used for this section has a diameter of 9.43 meters, a length of 200 meters, and a weight of 2,300 tons, powered by a 7,100 kW system.

source: https://www.crecg.com/zgztywz/10210594/10210606/10282800/index.html