Abstract:

To investigate the organizational aspects and cost structure associated with the maintenance of tunnel boring machine(TBM) tunnels, a comprehensive case study is conducted on the maintenance and rehabilitation of a TBM utilized in the North Qinling water diversion tunnel of the Hanjiang rivertoWeihe river water diversion project. The detailed examination includes the maintenance plan for the TBM′s main machine and its rear components, along with the allocation of manpower, materials, and machinery. Additionally, key technologies and construction methods related to the cutterhead, main drive, and gripper are discussed. Furthermore, the cost analysis of TBM main machine and its auxiliary maintenance is performed using technical measurement, statistical analysis, and mathematical statistics. The relationship between the TBM maintenance cycle, inspection cost, maintenance cost, and the original value of the equipment is scrutinized.  The findings reveal the following insights: (1) In the service life cycle of the TBM, a single overhaul is necessary to restore normal functioning, with the overhaul cycle spanning approximately 7 000 hours of main bearing running. (2) In situations where no maintenance cavern is available, the construction period for TBM tunnel maintenance and rehabilitation is estimated to be around 100 days. (3) The cost analysis indicates that the main machine and supporting equipment maintenance and rehabilitation costs for the TBM used in the North Qinling water diversion tunnel of the Hanjiang rivertoWeihe river water diversion project constitute approximately onequarter of the original equipment price. Furthermore, the cost of accessories constitutes approximately 78% of the total maintenance and rehabilitation cost, resulting in a maintenance cost coefficient ranging from 3.24 to 3.59.

Key words: tunnel, tunnel boring machine, overhaul and rehabilitation in tunnel, equipment transformation, overhaul cost