Impact of tunneling parameters on disc cutter wear during rock breaking in transient conditions

The assessment of disc cutter wear in subway shield construction beneath operational airports is a critical endeavor for evaluating the structural integrity of shield machines. This study delved into the linear tunnel project linking Station T1 to T3 within the Baiyun airport, focusing on the intricate relationship between tunneling parameters during rock-machine interactions and the impact of disc cutter installation radius on wear amount. In addition, dynamic impact transient rock-breaking tests of shield disc cutters were performed under the coupled thermo-hydro-mechanical triaxial conditions to ensure the validity of the relationship between mass-point velocity and the transient rock-breaking behavior of the disc cutter. The analysis revealed that when the shield thrust was between 17000 kN and 21000 kN, the total thrust of the shield had a significant effect on the advancement speed and cutterhead torque. Notably, the wear amount of the cutter increased approximately linearly with the installation radius, while the wear of the gauge cutter was also affected by the inclination angle. Furthermore, the study uncovered a linear correlation between the cutting length of the disc cutter and the magnitude of wear. Within a cutting length range between 440 km and 2276 km, the disc cutter's installation position had minimal impact on the wear coefficient. Simultaneously, this study employed the mass-point velocity to simulate the thrust and rolling forces in the equivalent shield tunneling processes. The findings underscored a positive correlation between disc cutter wear and shield advancement speed, cutterhead rpm, and mass-point velocity. When the mass-point velocity of the shield reached the maximum value of 0.666 m/s, the wear of the shield disc cutter also reached the maximum value of 27.5 mm, providing the quantitative reference for evaluating the influences of shield tunneling parameters on the cutter wear under transient impact rock breaking conditions.