Full-Scale Rotary Cutting Experimental Study and Development of Prediction Formulas for TBM Cutting Force

Estimation of cutting forces has been used in the design and performance prediction of tunnel boring machines. The relationship between rock strength and integrity, cutting force, torque, and vibration response was investigated by the synchronous monitoring system of the full-scale rotary cutting machine. The results showed that the penetration and rotation speed of the cutterhead were important operating parameters affecting the cutting force. Moreover, the penetration also greatly influenced the cutting force. The size, position, and frequency of the cutting force significantly correlated with the vibration of the cutterhead. The root mean square (RMS) of the acceleration component in the tunnel direction was the key feature. Soft–hard mixed stratum could be identified by the RMS of vibration. Based on these results, an empirical formula for predicting cutting force was constructed. The Colorado School of Mines model underestimated the normal forces acting on soft rocks, and the gradient boosting decision tree has the best effect in predicting the cutting force.