On March 29th, 2023, a 14.29m diameter 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 tunnelling 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 weight of 4250t, will traverse mainly weakly weathered argillaceous siltstone, weakly weathered sandstone and weakly weathered granite alongside adverse geological conditions including tectonic fault zones and joint intensive belts. The TBMs will alos be required to bore beneath major buildings and structures such as the Jiangmen tunnel on the Guangzhou-Zhuhai Railway, bringing strict requirements for machine performance and ground settlement control.
CREG has customized the TBM to cope with the challenging conditions such as long-distance water-rich hard rock stratum, continuous downgrade excavation, and extensive lengths of full face weakly weathered sandstone and granite. Dual mode including slurry and single shield mode, with the ability to switch rapidly between modes, was selected to ensure construction safety, quality and project schedule. Additionally, the TBM uses an auxiliary design of ‘cut ring freezing’ for hyperbaric intervention, to assist stability of a super-large diameter tunnel face and improve the safety coefficient of hyperbaric interventions. The TBM is also equipped with four targeted systems, to safeguard the steep and lengthy downhill boring gradient.
The entire 98.6km length of the Zhuhai-Zhaoqing High-speed Railway is located in the Guangdong province. It has a designed speed limit of 350km/h and will pass through Jiangmen Station and the Pearl River Delta Hub Airport allowing a seamless transfer between aircraft and train, further enhancing the Jiangmen Station as the West Pearl River Delta Transportation Center.
14.29m diameter TBM, is one among the largest
excavated diameter in the world.
The successful boring by TBM will prove that such
large diameter could also be done through
mechanised Tunnelling.
This is going to be the Engineering achievement
for all the professionals associated with the under
ground excavation.