Laboratory experimental study of a real-time monitoring system for TBM cutter force

For the purpose of identifying the rock mass conditions of the tunnel face and determining the TBM operating parameters, real-time monitoring of TBM cutter forces is required. For a TBM cutter mounted in the cutter box with a fixed wedge block, a cutter force measurement system is proposed to measure the cutter forces in the laboratory. The C-shaped block in the cutter box was replaced by a designed C-shaped block sensor as the force measurement component. By optimizing the structure of the C-shaped block sensor, a bi-directional force sensor with two full-bridge circuits on the bottom and side of the C-shaped block was built. The cutter force measurement system consists of two C-shaped bi-directional force sensors to measure the normal force, rolling force and side force of the cutter. The results of laboratory calibration experiments show that the cutter force measurement system is capable of measuring the cutter forces under various working conditions, and the linearity of the system is about 10 % for the overall force measurement. In general, the cutter force measurement system built with C-shaped force sensors has the advantages of accurate measurement, simple installation and stable operation. The system has great prospects for application in TBM tunneling.