Tunnel boring machine anchor shoe structure and process of operating a tunnel boring machine having such anchor shoe structure

摘要

The anchor shoes of a tunnel-boring machine arranged in a circular configuration are individually truncated by being tapered rearwardly so that the girth of the circular anchor shoe configuration can decrease progressively in order to accommodate convergence of superincumbent ground pressure. Preferably the anchor shoes are mounted for tilting of their aft portions to enable the degree of convergence or constriction to be altered. Chordal jacks connecting adjacent anchor shoes exert pressure on them resisting inward swinging of the aft portions of the anchor shoes resulting from superincumbent ground pressure.