Recently, the entire land-based mining section of the Shantou Bay Subsea Tunnel on the Shantou-Shanwei Railway, constructed by China Railway 14th Bureau Group, has been fully holed through. This section totals 5,636 meters and is a controlling project of the Shantou-Shanwei Railway.

The Shantou Bay Subsea Tunnel is the world's first single-tube, double-track high-speed railway subsea tunnel designed for a speed of 350 kilometers per hour. With a total length of 9,781 meters, it is located in an 8-degree seismic zone and successively crosses multiple fractured geological zones and zones of strong karst development. The construction of the land-based section holed through this time was affected by fault zones, uneven weathering of granite, and pore water and fissure water in the surrounding rock, posing high safety risks and construction difficulties.

During construction, in response to changes in the location of the tunnel's active fault relative to the original design position, the project adopted reinforcement measures such as full-face curtain grouting at the tunnel face and advanced middle pipe roofs, safely passing through the active fault. Facing complex geological conditions, the project adopted effective safety technical measures and new construction techniques during construction, increased the frequency of construction monitoring and measurement, and ensured the steady progress of the tunnel.

At present, the entire tunnel has cumulatively completed 85% of its total length in excavation.

Site of the sea-based mining section of the Shantou Bay Subsea Tunnel

To ensure the smooth progress of tunnel construction, the project established the "Sheng Sheng Sheng Innovation Studio" in July 2020, mainly conducting research on comprehensive construction key technologies for ultra-large cross-section, high-risk subsea tunnels under complex sea conditions. To date, it has applied for 10 utility model patents, with 5 entering the substantive examination stage; applied for 5 software copyrights, with 2 authorized; and completed 10 papers, of which 3 have been published and 4 have been accepted, achieving fruitful innovation results.

Innovation Studio

The Shantou-Shanwei Railway is an important component of the national "Eight Vertical and Eight Horizontal" coastal high-speed railway corridor designed for 350 kilometers per hour, and is also a key project in Guangdong Province. After the railway is completed and opened to traffic, the journey from Shantou to Guangzhou is expected to be shortened to about 1.5 hours.