Optimizing cutter wear in TBM operations through numerical analysis of enhanced rock-cutting interaction

The inevitable wear and degradation of disc cutters during the rock-crushing process significantly impacts the efficacy, timeline, and cost-effectiveness of tunnel construction. Optimizing cutter arrangements and adjusting suitable excavation parameters are crucial to reducing cutter wear in Tunnel Boring Machine (TBM) operations. This study probes the interaction between disc cutters and rock, employing an enhanced Bonding model to more accurately depict the failure behavior of rock specimens. Numerical simulations of the rock-breaking process using two disc cutters were conducted, focusing on highly influential excavation parameters—penetration depth (3, 5, 7, 9 mm) and cutter arrangements—tip width (14, 17, 20, 23 mm) and cutter spacing (50, 65, 80, 95, 110 mm). These simulations analyzed the impact of various factors on cutter force, wear, specific energy of rock breaking, and crushing unit rock cutter wear. The results show that increased penetration depth leads to higher cutter force and wear, with specific energy and unit wear remaining low when penetration is less than 5 mm. A larger cutter tip width incurs higher forces and wear of the first cutter, but when the tip width exceeds 20 mm, the force and wear of the second cutter will be reduced. Optimal specific energy for rock breaking and unit wear of rock volume were identified within a cutter spacing range of 80 to 95 mm. These findings can facilitate the analysis of how excavation parameters and cutter arrangements affect wear behavior, offering superior construction recommendations.