The influence of key structural parameters of main beam TBM on its dynamic characteristics

Full-face rock tunnel boring machine (TBM) bears changing large thrust, torque and overturning moment in the process of excavation, which causes mainframe vibration response. In order to reduce fatigue failure of mainframe and improve tunneling efficiency, a dynamic model of the main beam TBM mainframe was based on the dynamics simulation software, the dynamic response of mainframe and the influence law of main beam structural parameters on the dynamic characteristics of TBM were investigated. The results show that an increase in the length of the first main beam will cause its vibration to increase, and the vibration of the second main beam and saddle will decrease. An increase in the thickness of the first main beam will cause its vibration to decrease, the vibration of the second main beam increases slowly, and the vibration of the saddle first increases and then decreases. When the thickness of the upper and lower webs is 50 mm, the thickness of the side plates is 40 mm, and the thickness of the front and rear flanges is 105 mm, the vibration reaches maximum. The acceleration RMS of the cutterhead in the tunneling direction is 1.1g, and the acceleration RMS of the main beam is 0.21g, and as the vibration transferred backward gradually weakened, the frequency of varies is mainly between 0-50 Hz; According to the simulation results, the relevant parameters of the main beam were determined. The TBM has been applied for 2 years in a water diversion project, and the project has been successfully completed. Field test results show, the error between the three-way vibration test data and the simulation results is basically less than 20%. © 2020, Editorial Office of Journal of Vibration and Shock. All right reserved.