On March 29, 2023, a Φ14.29m dual mode TBM (“CREC 1192”), designed and manufactured by China Railway Engineering Equipment Group Co. Ltd. (CREG), rolled off the production line at the Shunde plant in Foshan city, Guangdong province. Together with CREC 1169, they will be used to excavate the Guifeng Mountain tunnel in the Jiangmen-Pearl River Delta Hub Airport section of Zhuhai-Zhaoqing High-speed Railway.
The tunneling section is 4.78km long and has the maximum water head of 75.67m. The dual mode TBM, with a total length of 145m and total weight of 4250t, will mainly go through weakly weathered argillaceous siltstone, weakly weathered sandstone and weakly weathered granite accompanied by adverse geological conditions including tectonic fault zones and joint intensive belts. Besides, it also needs to bore under major buildings and structures such as Jiangmen tunnel of Guangzhou-Zhuhai Railway. These bring strict requirements for the machine performance and ground settlement.
CREG has customized the TBM to cope with the construction difficulties such as long-distance water-rich hard rock stratum, continuous downgrade excavation and long-distance full face weakly weathered sandstone and granite stratum. Firstly, it selects dual mode TBM including slurry mode and single shield mode, which could ensure the construction safety, quality and project schedule at the same time. In addition, it adopts quick switching method to realize the quick switching between slurry mode/single shield TBM mode. What’s more, it uses the auxiliary design of cut ring freezing for hyperbaric intervention, which could guarantee the stability of super-large diameter tunnel face and improve the safety coefficient of hyperbaric intervention. Finally, it equips the TBM with 4 targeted systems, which safeguard the large gradient, long-distance and continuous downgrade construction.
The entire line of Zhuhai-Zhaoqing High-speed Railway with a total of 98.6km is located in Guangdong province. It has a designed speed limit of 350km/h and will pass through Jiangmen station and Pearl River Delta Hub Airport to realize the seamless transfer between aircraft and train, which will further enhance the Jiangmen station as the West Pearl River Delta Transportation Center.