Abstract: The mechanism of shield-soil interaction has always been a significant issue in academia and industry. For the active articulated shield, the presence of the active articulation system has an inevitable impact on shield-soil interaction. Therefore, a shield-soil interaction model considering active articulation was proposed and numerically solved using the time-incremental method. The model was validated through a case study of the Binzhong interval in Fuzhou Metro Binhai Express. The influence of active articulation on shield heading, resultant moment of earth pressure on shield shell, and resultant propulsion moment was carefully studied. Key conclusions include: (1) The shield-soil interaction during continuous excavation is more accurately reflected by the model and its numerical solution method. (2) Increasing the pitch articulation angle significantly reduces shield heading. (3) With a smaller coefficient of subgrade reaction, the articulation angle is approximately linearly correlated with the resultant moment of earth pressure; this relationship transitions to nonlinearity as the coefficient increases. In upper-soft lower-hard strata, the resultant moment varies with pitch articulation direction and becomes more pronounced with larger articulation angles. (4) Within the small-angle attitude correction range, a certain articulation angle reduces the resultant propulsion moment, enabling efficient attitude control. These findings provide theoretical support for shield axis deviation calculation and shield attitude control strategy.

Key words: shield tunnel, shield attitude, active articulation, shield-strata interaction, incremental process