Wuhu Chengnan Cross-river Tunnel Excavation Reaches Halfway Point

50% of the excavation of the largest diameter TBM tunnel in An Hui Province, China, has now been completed, with the most complex geological conditions, the most difficult construction and the highest risk in the middle and lower reaches of the Yangtze River. In order to make this large infrastructure project a reality, two 15.07m diameter slurry TBM are working non-stop on the construction works. One of them is equipped with CREG (China Railway Engineering Equipment Group Co. Ltd. ) key technologies including cutter full-state monitoring and excavation geological perception.

These technologies enable the large TBM to excavate the tunnel more efficiently, stably and intelligently and avoid the abnormal damages of cutters, as they could provide scientific guidance for TBM drivers to change cutters and optimize tunneling parameters based on cutter status monitoring to avoid tunneling risks. The intelligent cutter diagnosis technology has accurately judged abnormal damage status such as uneven wear and cutter edge cracks during the application process many times. The real-time perception technology of the tunnel face based on the state of the cutters has realized the inversion and inference of the geological state of the tunnel face at present, provided guidance for the optimization of tunneling parameters, and improved the tunneling efficiency. Through the big data statistical analysis of the clogging phenomenon and cutter load under different geological conditions, the cutter head clogging warning and cutter load monitoring technology can optimize and guide the design of cutter head and cutter, and overcome the clogging challenge by optimizing the designs of cutter head opening rate, cutter layout and cutter height setting.

“Cutter status monitoring helps us a lot and has basically become a standard for TBM construction in complex ground.” the project manager says. The above-mentioned key technologies transform the high-intensity, high-risk, and high-pollution TBM working environment into a relatively safe and efficient green construction mode, with real-time perception of cutter status, early warning of clogging on the cutter head, geological perception of the tunnel face, and cutter operation and maintenance management and have been praised by many clients.