Development and Application of Cutterhead Working Status Monitoring System for Shield TBM Tunnelling

During the shield TBM tunnelling, the working status of the cutterhead is difficult to be determined because the pressured chamber is located behind the cutterhead. In this paper, a cutterhead working status monitoring system for shield TBM tunnelling was developed to monitor the working status of the cutterhead in real time. The system consists of data acquisition subsystem, control and data transmission subsystem, as well as data processing and display subsystem. The cutter wear, cutter rotation speed and cutterhead temperature can be monitored and transmitted to the system software through the central port by cable and wireless. The system software can simultaneously display the TBM operating parameters and cutterhead working status parameters, predict the cutter life and present early warning of abnormal working status. The system has been successfully applied in a shield tunnelling project. Based on the analysis of the monitoring data, it was found that the normal cutter wear mainly depended on the rock abrasiveness and cutter rotation distance. The difference in cutter wear rate in the different ground was more than 3 times. The relative sliding between the cutter and the tunnel face was widespread. The sliding distance in low-abrasive formations exceeded 1/3 of the cutter track length. Under the normal tunneling conditions, the cutterhead temperature was lower than 50°. The successful application shows that this system can work stably in long term under harsh work environment and provide guidance for shield TBM tunnelling.