"Shenzhen Fabu" (Shenzhen Release) official WeChat account stated in a post that in China's deepest subsea tunnel — the Pearl River Estuary Tunnel of the Shenzhen-Jiangmen Railway — the super-large-diameter shield tunneling machine "Greater Bay Area" was the first to complete all 1,468 rings of excavation, reaching the designated mileage, marking major progress in the construction of the entire Shenzhen-Jiangmen Railway line.

　　The Shenzhen-Jiangmen Railway is an important component of the coastal corridor of the national "eight vertical and eight horizontal" high-speed rail network. Because the line needs to cross the Pearl River estuary between Guangzhou and Dongguan, the geological and hydrological conditions are extremely complex. After several rounds of comparison and selection in the design scheme, it was ultimately changed from a road-rail dual-purpose bridge to an undersea tunnel.

　　As the controlling project of the entire line, the Pearl River Estuary Tunnel of the Shenzhen-Jiangmen Railway has a total length of 13.69 kilometers and uses two shield tunneling machines excavating toward each other. The shield-method tunnel in Section 2, constructed by China Railway Tunnel Group, is 2,930 meters long. The tunnel's maximum underwater burial depth is 115 meters, and the maximum water pressure is as high as 1.06 MPa, setting China's record for the deepest subsea railway tunnel.

　　According to a previous report by IT Home, the project began in December 2021. The "Greater Bay Area" shield tunneling machine was tailor-made for the Pearl River Estuary Tunnel of the Shenzhen-Jiangmen Railway, with an excavation diameter of 13.32 meters, a total length of 133 meters, and a total weight of about 3,900 tons.

　　The "Greater Bay Area" shield tunneling machine successively passed through nearly 21 types of geological conditions and 9 fault fracture zones. During this period, it achieved impressive results of 24 meters of excavation in a single day and a maximum monthly excavation of 432 meters.