On Dec. 28, “CREG 599” – a full face hard rock shaft boring machine – broke through the ventilation shaft of Ninghai Pumped Storage Power Plant. Independently developed by China Railway Engineering Equipment Group Co. Ltd. (CREG), the successful application of full face hard rock shaft boring machine marks that CREG has successfully overcome the world-class technical problem of a full face hard rock shaft boring machine and realized underground unmanned tunneling in a shaft for the first time.
Water headrace systems, such as pressure shafts, ventilation shafts and access shafts, are characterized by difficult construction, poor environment, high labor intensity and risk factor, which are the difficulties of underground construction projects. With the continuous development of science and technology, the society’s thirst for efficient, safe, and new-type shaft construction technology is increasing. However, the high-end equipment for mechanized and intelligent shaft construction full face hard rock shaft boring machine and its construction technology are still great challenges in the world.
“CREC 599” with an excavation diameter of 7.83 m integrates the traditional shaft construction technology and the construction concept of full face TBM. The machine has a capability of building the shaft safely and efficiently and realizing underground unmanned tunnelling. The excavated shaft is nearly 200 m deep, with good integrity of surrounding rock and high rock strength. Faced with many challenges such as no precedent, complex geology and difficult construction, CREG team created a series of pioneering technologies:
-Tailored thrust technology with independent intellectual property rights, which provides reliable and stable thrust power for the machine;
-Mechanical synchronous muck discharge system with independent intellectual property rights, which has higher efficiency and lower energy consumption than traditional muck discharge methods such as slurry and vacuum, and solves the international difficulty of simultaneous operation of excavation and muck discharge;
-Remote control system for shaft construction, which enables the operator free from working in the shaft, and realizes unmanned construction of underground full face hard rock excavation for the first time.
Compared with other traditional construction methods, the construction personnel of full face hard rock shaft boring machine developed by CREG are reduced by over 50%, and the tunnelling efficiency is increased by more than twice. During the excavation, “CREC 599” realized unmanned underground construction, automatic excavation and overground remote control, which provides experience and reference for similar underground construction projects, and offers new solutions to the technical problems of excavating a kilometric shaft using full face tunnelling method.