Coupling dynamic characteristics of tunnel boring machine cutterhead system with multi-source uncertainties

Abstract

During tunnel boring machine (TBM) tunneling, the violent vibration of the cutterhead system is the major cause of structural failure and engineering accidents. There are many uncertain coupled factors of the cutterhead system, which can lead to inaccurate vibration analysis and difficulty predicting the dynamic response. In this study, coupling dynamic characteristics under multi-source uncertainties of the TBM cutterhead system were analyzed. First, a geological uncertain coupling model and disc cutter uncertain coupling model were established. Then, the load interval boundaries with multi-source uncertainties under different working conditions were obtained and the load interval boundary was combined with the cutterhead dynamic model to establish a dynamic model with multi-source uncertainties. Finally, a dynamic characteristic analysis was carried out using a real-world engineering example to validate the model. The results show that when multi-source uncertainties are considered: (1) The maximum increase in the radial load amplitude and corresponding load interval median are about 137% and 73%, respectively. The maximum increase in the overturning moment amplitude and the load interval median are roughly 92% and 93%, respectively. (2) Under typical working conditions, the maximum increase in the stability vibration response boundary is about 92% for the radial displacement response, with a maximum increase in overturning angle displacement of 70%. (3) The optimum mass fraction of the cutterhead center block is around 46.5%, resulting in the smallest vibration amplitude. The results provide a theoretical reference for the design of cutterhead structures for vibration reduction.