Directional control of EPB shield in spiral curve

A Geometric Model for a Shield TBM Steering Simulator

“…Chanchaya and Suwansawat [4] introduced three operational factors (articulation angle, shield jack length difference, and copy cutter stroke) that are necessary for curved excavation and derived calculation methods for those factors and methods for forming curved alignments, including circular and spiral curves in two-dimensional space. They also compared three operational factors obtained from theoretical calculations with those measured in a real guidance system.…”

“…These previous studies highlight limitations in designing the steering system for the TBM simulator. Sugimoto and Sramoon [1] presented various factors related to shield behavior; Chanchaya and Suwansawat [4] introduced operational factors for TBM curved excavation, and the TBM navigation system (the critical part of the steering system) was partially covered in both studies. Shen et al [2,3] suggested determining the TBM position and its deviation caused by pitch, yaw, and roll, but considered only one reference point when calculating TBM position, whereas at least three reference points must be considered for a navigation system in three-dimensional space.…”

“…Shield jack extension differences, by one-sided extension and the use of tapered segments, are required for successful curved excavation [4]. Here, we assumed that the shield jacks are extended equally, simultaneously, and at the same rate.…”

“…The X-type system involves the extension and retraction of the articulation jack simultaneously during articulation, with the articulation point always being at the center of the shield (Figure 1a). Shield jack extension differences, by one-sided extension and the use of tapered segments, are required for successful curved excavation [4]. Here, we assumed that the shield jacks are extended equally, simultaneously, and at the same rate.…”