Study on influencing factors of cutting efficiency for TBM gage cutters by linear cutting test

Abstract

The gage cutter is the key component in a tunnel boring machine (TBM); this part affects the machine’s cutting efficiency and maintains the tunnel diameter. In this study, a series of rock cutting tests with different parameters (cutting spacing, penetration depth, and installation angle) is conducted using the mechanical rock fragmentation experimental platform of Beijing University of Technology to study the influences of these parameters on the rock-breaking performance of a TBM gage cutter. During the tests, the triaxial cutting forces and rock chips are collected and analyzed. The test results show that the average normal force of the cutter will decrease with the installation angle increasing at the same penetration depth and cutting spacing, but the average rolling force has the opposite change tendency. The side force is influenced by the installation angle significantly. The side force of the gage cutter plays a more important role in the rock fragmentation than does the side force of the normal cutter. Moreover, the cutting efficiency of the normal cutter is higher than that of the gage cutter. An inclined disc cutter is more conducive to producing rock chips under a large cutting spacing than is a vertical disc cutter, and the optimal cutting spacing under different installation angles is different. This study can provide a reference for TBM gage cutter design and TBM operation parameter optimization.