Abstract
Disc cutter wear in TBM tunneling is caused by initial fragmentation of a solid rock face (the primary fragmentation) and fragmentation of residual rock pieces between a cutterhead and a face (the secondary fragmentation). The authers have studied the relationship between the rate of cutter wear caused by primary fragmentation and the modified F value, and analyzed the proportion of cutter wear caused by secondary fragmentation in four projects. It was concluded that there was a good correlation between the two indices, and that the secondary fragmentation invited the excessive cutter wear beyond the estimation in the two projects.
