Abstract: A selfadaptive control method for the shield posture based on the thrust vector technology is proposed, in order to solve the problem of the fluctuations in the tunnel axis caused by the shield drivers. The control method is comprehensively elaborated from three aspects: the overall logic structure design, the rectifying movement path planning, and the shield posture control strategy and methods. The control method is applied in the construction of the Wusongkou river-crossing tunnel on Shanghai-Nantong railway, and conclusions drawn are as follows: (1) Due to the good execution of the target pressure of the propulsion cylinders, a good collaborating relationship between the target total thrust and the actual total thrust is observed, and the shield has a stable advancing speed. (2) The target horizontal moment of the total thrust and the actual horizontal moment of the total thrust are highly consistent; however, due to the influence of the overburden thickness and the geological conditions, the target vertical moment of the total thrust is slightly higher than the actual vertical moment of the total thrust so as to maintain good shield posture adjustment capability in the vertical direction. (3) The relationship between the acting point of the total thrust and the posture of the shield in the horizontal direction and in the vertical direction roughly takes a "sugar-coated haws"-shaped feature, the deviation of the shield posture can be rectified and the shield posture can be controlled.

Key words: thrust vector technology; shield posture, self-adaptive control, path planning, engineering application