Study on Calculation Method of Shield Length and Thrust of TBM in Deep High Stress Tunnel

Rock tunnel boring machine (TBM) is a safe, fast and effective tunnel excavation equipment. However, TBM is prone to get stuck when TBM is excavating complex and high in-situ stress tunnels. Therefore the influence of geological environment should be considered as much as possible at the beginning of TBM design to reduce the risk of TBM sticking. By analyzing the influences of high stress conventional stratum and high stress soft and broken rock stratum on TBM, two criteria of TBM jamming in high stress conventional formation and high stress soft broken formation were proposed. According to the two criteria, the theoretical calculation method of shield length design and thrust design of high stress tunnel TBM considering surrounding rock mechanical parameters was proposed, and the basis of parameter selection was given. Finally, the rationality of the existing TBM design was calculated and analyzed based on actual surrounding rock geological parameters of a high stress tunnel in Southwest China. The study can provide basis for the design and calculation of shield length and thrust of TBM.