Shenzhen's first cross-sea passage has made further progress. Reporters learned on December 1 that the right-line shield tunneling of the cross-sea passage, constructed by the Shenzhen Transportation Public Facilities Construction Center, China Railway South, and China Railway Tunnel Group, has successfully surpassed 500 meters. The project is expected to officially begin tunneling "into the sea" at the end of this month.

The Shenzhen Mawan Cross-Sea Passage starts at the intersection of Mawan Avenue and Yueliangwan Avenue in the Mawan Port Area of Qianhai, and connects with the Dachan Bay Toll Station of the Yanjiang Expressway and the intersection of Jinwan Avenue and Xixiang Avenue. It is divided into above-ground and underground road sections, with a total length of 8.05 kilometers. The shield section of the Mawan Cross-Sea Passage Lot 2 project undertaken by China Railway Tunnel Group has a total length of 2,063 meters, including 1,100 meters in the sea area. A domestically produced shield machine named "Mawan" was tailor-made for the project, and it is also the largest-diameter shield machine used in underwater tunnel construction in China.

Zhao Yong, an engineer at the Shenzhen Transportation Public Facilities Construction Center, told reporters that more than 50% of the ground encountered by "Mawan" consists of uneven strata with soft upper layers and hard lower layers, and the maximum rock strength reaches 193 MPa. The repeated variability of the strata has brought severe challenges to the project. During construction, builders from China Railway Tunnel Group relied on the intelligent shield TBM engineering big data platform to achieve real-time intelligent monitoring and automatic warning of tunneling parameters. Technologies such as digital Beidou positioning, informatized BIM, 5D, and intelligent monitoring were used to comprehensively perceive the surrounding environment of the project construction, changing the traditional methods of manual supervision and manual setting-out, and greatly improving construction accuracy and monitoring efficiency.

According to Wang Binbin, chief engineer of the Mawan Cross-Sea Passage project of China Railway Tunnel Group, while the project team operated this "national treasure" more than five stories high and struggled to tunnel through complex strata with uneven hardness, it also attached great importance to environmental protection. It adopted a zero-emission slurry collection design for shield machine pipeline extension, achieving zero leakage and zero pollution of slurry, ensuring the overall construction environment of the tunnel and practicing the concept of green development.

As Shenzhen's first large-diameter sea-crossing shield tunnel, the Mawan Cross-Sea Passage is expected to be completed and opened to traffic by the end of 2023.