Evaluation of TBM Cutterhead’s Comprehensive Performance Under Complicated Conditions

A comprehensive performance evaluation method for the tunnel boring machine(TBM) cutterhead is proposed in this paper. The evaluation system is established on strength and vibration. Based on fracture mechanics theory, fatigue strength evaluation indices are determined under critical crack length. The concept of crack regions division is proposed to evaluate fatigue strength more accurately and specifically. In addition, the velocities in three directions of critical locations are obtained with dynamics equations. Then, the root-mean-square values of velocities are taken as the vibration severity indices. Taking the cutterhead of Jilin diversion engineering as an example, the evaluations of each index are completed; then, the vibration of the TBM cutterhead is measured and compared with the theoretical calculation results. There are similar change laws between the theoretical calculation results and the testing results of the cutterhead acceleration, which proves that the method of calculation of the vibration index is effective, the reliability of the cutter saddle welding should be paid attention to when the TBM is working, and the condition of vibration severity of the TBM cutterhead meets the requirements but needs to be improved.