Investigating Rock-Breaking Mechanisms Under TBM Hobs: Energy Analysis and Finite Element Modeling

Underground engineering has led to the rapid development of tunnel boring machines (TBM), which have been used in practical projects such as transportation, municipalities, water, and electricity in recent years due to advantages such as excavation speed. Excavation speed, high safety, and good construction quality greatly affect the life of the hobs (disc cutters of TBMs). The rock-breaking process for rock crushing under the forces of TBM hobs was numerically performed using LS-DYNA software based on the finite element method. A full-section model with five hobs was used to simulate the rock-breaking process of hobs. In addition, an analysis was performed on the internal and kinetic energy involved in the rock-cutting and breaking processes under TBM hobs. The results show that the vertical force plays a major role in the rock-breaking process of the hob, and the values of the lateral force and the rolling force are small and do not affect it. The results obtained from this simulation can be used as boundary conditions for bearing analysis. Numerical and theoretical results were compared to verify the reasonability of the constructed constitutive model.