By ashleykaren
A CREG‘s designed and manufactured Φ14.29m dual mode TBM (“CREC 1192”) rolled off the production line at the Shunde plant in Foshan City, Guangdong province.
Jointly with CREC 1169, they will be employed to bore the Guifeng Mountain tunnel in the Jiangmen-Pearl River Delta Hub Airport section of the Zhuhai-Zhaoqing High-speed Railway.
The tunneling section is 4.78km long and has a max water head of 75.67m. The dual-mode tunnel boring machine, with a total length of 145m and a total weight of 4250t, will specifically go through weakly weathered argillaceous siltstone, weakly weathered sandstone, and weakly weathered granite accompanied by adverse geological conditions, such as tectonic fault zones and joint intensive belts.
Similarly, it also must excavate under principal buildings and structures such as the Jiangmen tunnel of the Guangzhou-Zhuhai Railway. These bring rigid requirements for the TBM performance and ground settlement.
China Railway Engineering Equipment Group Co., Ltd. has customized the machine to adjust to the construction challenges such as long-distance water-rich hard rock stratum, continuous downgrade boring and long-distance full face weakly weathered sandstone and granite stratum.
Firstly, it picks dual mode machines such as slurry mode and single shield mode, which could ensure the construction safety, quality, and project timetable at the same time. Secondly, it selects a fast-switching method to learn the quick switching between slurry mode/single shield TBM mode.
Moreover, it uses the auxiliary design of cut ring freezing for hyperbaric intervention, which could secure the stability of the super-large diameter tunnel face and enhance the safety coefficient of hyperbaric intervention.
Finally, it prepares the machine with four targeted systems, which safeguard the large gradient, long-distance, and continuous downgrade construction.
The complete line of the 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 is said to pass through Jiangmen station and Pearl River Delta Hub Airport to discover the seamless transfer between aircraft and train, which will also improve the Jiangmen station as the West Pearl River Delta Transportation Center.
