Analysis of parameters for large cross-section quasi-rectangular EPBM in water-rich sandy strata

Water-rich sandy stratum, characterized by high permeability, low cohesion, and strong fluidity, poses critical challenges for large-section quasi-rectangular Earth Pressure Balance Shield Machine tunneling. Based on a quasi-rectangular shield tunneling project in the water-rich sandy stratum of Zhengzhou Metro Line 8, this study focuses on optimizing tunneling parameters. Through field measurements and statistical analysis, the evolution patterns of key parameters-including chamber pressure, cutterhead torque, total thrust, screw conveyor torque, grouting pressure, grouting volume, and advance rate-are investigated. Recommended value ranges for these parameters are proposed. The research outcomes provide data support and practical guidance for quasi-rectangular shield tunneling under similar geological conditions.