Recently, the left line of the Ji-Gu shield tunneling section of the Jiqian section of the Guangzhou-Dongguan-Shenzhen Intercity Railway was successfully completed, marking the dual-line breakthrough of the longest undersea tunnel of an intercity railway in China.

The Jiqian section of the Guangzhou-Dongguan-Shenzhen Intercity Railway is an important component of the Guangzhou-Shenzhen main axis of the Greater Bay Area intercity railway network. It starts at the already operational Shenzhen Airport Station of the Guangzhou-Shenzhen Intercity Railway and ends at Qianhai Station, with a total length of approximately 15.2 kilometers, using underground alignment. The line has 3 stations in total: Xixiang, Bao'an, and Qianhai. The project is designed for a speed of 160 km/h and uses 8-car CRH6-type EMU trains.

The Jiqian section of the Guangzhou-Dongguan-Shenzhen Intercity Railway passes beneath the Xiwan sea area for a length of approximately 3.1 kilometers, constructed using a slurry balance shield tunneling machine with an excavation diameter of 9.14 meters. It is the tunnel with the longest single-head excavation distance and the ** undersea crossing tunnel on the entire line, and also the project with the highest environmental risk on the entire line. The left line of the section completed this time is 4,368.2 meters long, totaling 2,426 rings. During construction, the shield machine intensively passed through 9 types of strata, including highly water-sensitive soil layers and high-strength granite formations.

Shenzhen Metro Group organized the participating construction units to overcome a series of technical challenges, including long-distance tunneling of a large-diameter shield under high water pressure and complex strata, frequent opening of the chamber for cutter replacement in high-strength hard rock, replacement of shield tail brushes inside the tunnel, and reinforcement of the large ring of the cutterhead. Facing the dual pressure of environmental conditions and schedule, all parties worked in coordination, continuously optimized the construction plan, and ensured continuous and safe shield tunneling, successfully completing the breakthrough objective.

As an important link of the Guangzhou-Dongguan-Shenzhen Intercity Railway, once the Jiqian section is completed and opened, intercity trains will directly reach Qianhai and Bao'an Central. This is of great significance for improving the intercity network of the Guangdong-Hong Kong-Macao Greater Bay Area and achieving integrated regional economic development.