Design method of installed cutterhead parameters for dual-mode TBM in complex ground: An example of Yangtze-River-to-Han-River Water Diversion Project

For Yangtze-River-to-Han-River Water Diversion Project, the Tunnel Section 10, which will be excavated by tunnel boring machine (TBM), subjects to large tunnel diameter, low buried depth, low rock mass grade, large rock mass strength difference and excessively developed underground water, which bring serious engineering problems such as low rock breaking adaptation, high water/mud inrush risk, large rock mass deformation and low ground instability. The sole use of traditional hard rock TBM or traditional shield TBM cannot meet the changeable geological conditions, thus cannot achieve the expected excavation schedule and quality. Therefore, this study investigates the feasibility of using EPB (Earth Pressure Balance)-SS(Single Shield) dual mode TBM in Tunnel Section 10. The design methods for installed cutterhead parameters such as thrust and torque are proposed respectively based on the EPB mode and the SS mode, and the final installed TBM cutterhead parameters for Tunnel Section 10 are determined by combing the design results of these two modes. The design methods for installed cutterhead parameters of dual mode TBM can provide references and guidance for EPB-SS dual mode TBM design of similar tunnel projects.