Chained dynamic reconfiguration optimization for nonuniform shield propulsion system layouts and thrust fluctuation stability evaluation methodology

Based on the engineering challenge of dynamic stability control for shield propulsion systems under complex geological conditions, this study aims to address two critical issues: adaptive optimization of nonuniform configurations during multi-ring continuous tunneling and long-term stability evaluation. By establishing a segmented progressive reconfiguration mechanism with the core constraint of minimizing phase angle adjustment quantities between adjacent configurations, analytical optimization algorithms achieve rapid and energy-efficient switching of nonuniform layouts. Simultaneously, this work innovatively proposes the Thrust Stability Coefficient ( TSC ). A quantitative dynamic stability evaluation model is developed by coupling the discrete characteristics of thrust variation coefficients with their mean levels. Numerical simulations and field validation demonstrate: The nonuniform thrust system reduces TSC values by 85%, while the overall TSC at the Duesseldorf WHL Metro Project in Germany is further reduced by 70% during continuous construction. Adams virtual prototype simulations validate the effectiveness of TSC in characterizing the stability of chained nonuniform configurations. The theoretical framework of “dynamic reconfiguration optimization—global stability evaluation—long-term safety control” established in this research not only provides innovative solutions for shield propulsion systems under complex geological conditions, but also delivers critical technical support through its engineering data-driven verification methodology and chain optimization strategy for the stability control of intelligent tunneling equipment in underground engineering.