| A tunnel boring machine(TBM)is a construction machinery used to excavate tunnels of circular cross section through a variety of soil and rock strata.Disk cutter,as the primary tool of the TBM to excavate rock,its rock cutting performance and loading state are key factors impacting TBM’s tunneling efficiency.In order to measure the forces acting on the disk cutter and its vibration status,an experimental setup is developed.The setup called TBM Test is horizontal frame type structure equipped with a small size cutter head and three disc cutters.The main structure of TBM Test includes transmission structure,rock specimen fixture structure,rock specimen propulsion structure and cutter head.We have designed these structures above and verified them by means of finite element analysis.The result shows that each structure can work well under the most dangerous working conditions.We can achieve the measurements of total thrust and torque of the testing machine,as well as the forces acting on the disc cutters.The accuracy of the measurement scheme can be guaranteed,because the program is based on the structural characteristics of the test machine and the way the hob is installed.A combined sensor of compression and torsion is installed between the cutter head and the main shaft to measure the total thrust and total torque.Besides,three groups of modified C-shape blocks,used to fix the disc cutters,are employed as tri-direction forces sensors to measure the normal force,rolling force and side force of each disc cutter.The sensors are calibrated and are confirmed to have good linearity and repeatability.Preliminary operation shows that the main structures are running well and the corresponding logical relationships are correct.Subsequently,concrete specimen is prepared to conduct a rock cutting experiment.Total thrust and total torque of the testing machine and the forces acting on the disc cutters are measured,which verifies the testing machine’s function well. |
