Comparison of the mechanical performance between two-stage and flat-face cutter head for the rock tunnel boring machine (TBM)

Abstract

To overcome the drawbacks of the large flat-face TBM cutter head (for example, enormous rock cutting forces and eccentric forces cause excessive deformation of the cutter head and damage to the main bearing), a two-stage cutter head is introduced. The two-stage cutter head was designed using grey relational analysis method according to the flat-face cutter head applied in the West Qinling Tunnel, China. The mechanical performance analysis models of the two cutter heads in the layered-banded rock (LBR) mixed ground were built to calculate the cutter heads’ rock cutting thrust and torque, eccentric forces and overturning moments. The two cutter heads’ deformation and stress distribution were also compared. We concluded that with the same penetration, the thrust, torque, eccentric force, overturning moment, deformation and maximum stress of the two-stage cutter head were smaller than those of the flat-face cutter head.