CREG Baiyun Pioneer, a shield TBM manufactured by the China Railway Group, broke through rock to complete boring on the tunnel.
The Baiyun Airport T3 transportation hub railway reserve project includes the Baiyun Airport T3 hub station, the Guangzhou-Heyuan high-speed railway (Guangcong Intercity), the Guangzhou-Zhuhai- Macao high-speed railway section tunnel, and the east and west section tunnels of the Fangcun to Baiyun Airport Intercity.
These sections total 5.5km, with one station and four tunnels.
The 1.476km-long Guangzhou-Zhuhai-Macao high-speed railway section tunnel posed significant construction challenges: the karst cave detection rate was 48.94%, and the karst line rate was 13.54%. In addition, 98% of the shield tunnelling route was within the airport’s operational flight zone, with the tunnel passing directly underneath the airport runway, and the vertical distance from the tunnel segment to the ground surface of the flight zone was only about 11.246m.
The shield tunnelling phase required strict control over the total cumulative settlement, which was not to exceed 30mm, with uplift limited to 10mm. Differential settlement could not exceed 1%, and segment joint misalignment had a 5mm tolerance.
The height restrictions at the airport and limited working space also created challenges, including insufficient launch shaft length and ultra-shallow shield tunnelling.
To ensure the project proceeded smoothly, China Railway (Guangzhou) Investment & Development co-ordinated and integrated resources, partnering with the China Railway Tunnel Group, which was responsible for the shield tunnelling work. They deployed the largest diameter shield machine currently used in Guangzhou metro construction – the 14.31m-diameter CREG Baiyun Pioneer shield machine.
The TBM is 115m long, weighs approximately 2,500 tons, and is equipped with online tool monitoring, advanced geological forecasting functions, a dual-channel muck removal system (screw machine + direct discharge pipe), as well as cutting-edge automated grouting detection and equipment status monitoring technologies.
