ABSTRACT
The Tunnel Boring Machine (TBM) tunneling process in hard rock involves breaking a rock mass that is not necessarily intact. The performance of this process heavily relies on the rock breakage efficiency induced by the TBM cutter head. Both the characteristics of the rock mass and the specifications of the TBM influence the rock breakage and chipping process, ultimately affecting the machine’s efficiency. This study introduces an approach to optimize the cutter replacement strategy in anisotropic hard rock using Finite Element Analysis (FEA). Through 3D numerical modeling, the load paths for different cutter patterns are simulated, considering a variable load distribution. The optimization of cutter spacing is based on several defined criteria, including chip thickness and chipping stress. Additionally, the influence of rock anisotropy in this study as a critical factor was investigated, as it directly affects the rock breakage and chipping process during TBM operations. This study addresses these challenges by incorporating anisotropic characteristics into the FEA models, allowing a simulation of load paths and cutter interactions. By varying cutter spacing and thrust forces, the study identifies optimal configurations that account for the anisotropic nature of the rock, thereby enhancing the efficiency of rock fragmentation. This nuanced understanding helps in designing more effective cutter strategies that accommodate the directional dependencies of rock properties, leading to improved TBM performance and reduced wear on the machine.
