Analysis of Plane Attitude and Overexcavation Control of Shield Tunneling Machine in Transition Curve Section

The attitude control of the shield machine is mainly realized by the telescopic pushing jack and the control of the elongation of the over-excavation cutter. Due to the complexity of the curve line of the transition curve section, the attitude of the shield machine is often difficult to control. In view of the above problems, based on the over-excavation mode and plane attitude analysis of the shield machine, the reasonable over-excavation mode of the shield machine is determined to be the inner half-circle over-excavation, and the difference between the inner and outer pushing strokes and the maximum elongation of the over-excavation cutter is calculated. In the calculation process, a two-dimensional plane is used to simplify the jacking jack of the shield machine, and only the influence of the jacks at the left and right ends on the attitude of the shield machine is considered. Finally, the calculation formulas of the jacking stroke difference and the maximum elongation of the over-excavation cutter of the shield machine in the straight-line transition curve section and the transition curve section are obtained. Taking the construction data of a project into the above formula, it is concluded that the push stroke difference between the inner and outer sides of the straight line into the transition curve section and the maximum elongation of the over-excavation cutter is in a quadratic parabola relationship with the tunneling distance of the shield machine, and the transition curve section. The research can provide a scientific basis for the plane attitude and over-excavation control of the shield machine when the shield machine is over-gentle curve.